Merge remote-tracking branch 'eugenp/master'

README.md

@@ -2,41 +2,22 @@
 The "REST with Spring" Classes
 ==============================
 
-Here's the Master Class of REST With Spring (price changes permanently next Friday): <br/>
+Here's the Master Class of REST With Spring (along with the newly announced Boot 2 material): <br/>
-**[>> THE REST WITH SPRING MASTER CLASS](http://www.baeldung.com/rest-with-spring-course?utm_source=github&utm_medium=social&utm_content=tutorials&utm_campaign=rws#master-class)**
+**[>> THE REST WITH SPRING - MASTER CLASS](http://www.baeldung.com/rest-with-spring-course?utm_source=github&utm_medium=social&utm_content=tutorials&utm_campaign=rws#master-class)**
 
 And here's the Master Class of Learn Spring Security: <br/>
-**[>> LEARN SPRING SECURITY MASTER CLASS](http://www.baeldung.com/learn-spring-security-course?utm_source=github&utm_medium=social&utm_content=tutorials&utm_campaign=lss#master-class)**
+**[>> LEARN SPRING SECURITY - MASTER CLASS](http://www.baeldung.com/learn-spring-security-course?utm_source=github&utm_medium=social&utm_content=tutorials&utm_campaign=lss#master-class)**
 
 
 
-Spring Tutorials
+Java and Spring Tutorials
 ================
 
-This project is **a collection of small and focused tutorials** each covering a single and well defined area of development. 
+This project is **a collection of small and focused tutorials** - each covering a single and well defined area of development in the Java ecosystem. 
-Most of the tutorial projects are focused on the `Spring Framework` (and `Spring Security`).  
+A strong focus of these is, of course, the Spring Framework - Spring, Spring Boot and Spring Securiyt. 
 In additional to Spring, the following technologies are in focus: `core Java`, `Jackson`, `HttpClient`, `Guava`. 
 
+
 Building the project
 ====================
 To do the full build, do: `mvn install -Pdefault -Dgib.enabled=false`
-
-
-Working with the code in Eclipse
-================================
-Any IDE can be used to work with the projects, but if you're using Eclipse, consider the following. 
-
-- import the included **formatter** in Eclipse: 
-`https://github.com/eugenp/tutorials/tree/master/eclipse`
-
-
-CI - Jenkins
-================================
-This tutorials project is being built **[>> HERE](https://rest-security.ci.cloudbees.com/job/tutorials-unit/)**
-
-### Relevant Articles: 
-================================
-
-- [Apache Maven Standard Directory Layout](http://www.baeldung.com/maven-directory-structure)
-- [Apache Maven Tutorial](http://www.baeldung.com/maven)
-- [Designing a User Friendly Java Library](http://www.baeldung.com/design-a-user-friendly-java-library)

algorithms/src/main/java/com/baeldung/algorithms/kthlargest/FindKthLargest.java

@@ -98,7 +98,7 @@ public class FindKthLargest {
 
     private int randomPartition(Integer arr[], int left, int right) {
         int n = right - left + 1;
-        int pivot = (int) (Math.random()) % n;
+        int pivot = (int) (Math.random() * n);
         swap(arr, left + pivot, right);
         return partition(arr, left, right);
     }

algorithms/src/main/java/com/baeldung/algorithms/quicksort/QuickSort.java

@@ -0,0 +1,39 @@
+package com.baeldung.algorithms.quicksort;
+
+public class QuickSort {
+
+    public static void quickSort(int arr[], int begin, int end)
+    {
+        if (begin < end) {
+            int partitionIndex = partition(arr, begin, end);
+
+            // Recursively sort elements of the 2 sub-arrays
+            quickSort(arr, begin, partitionIndex-1);
+            quickSort(arr, partitionIndex+1, end);
+        }
+    }
+
+    private static int partition(int arr[], int begin, int end)
+    {
+        int pivot = arr[end];
+        int i = (begin-1);
+
+        for (int j=begin; j<end; j++)
+        {
+            if (arr[j] <= pivot) {
+                i++;
+
+                int swapTemp = arr[i];
+                arr[i] = arr[j];
+                arr[j] = swapTemp;
+            }
+        }
+
+        int swapTemp = arr[i+1];
+        arr[i+1] = arr[end];
+        arr[end] = swapTemp;
+
+        return i+1;
+    }
+
+}

algorithms/src/main/java/com/baeldung/algorithms/quicksort/ThreeWayQuickSort.java

@@ -0,0 +1,38 @@
+package com.baeldung.algorithms.quicksort;
+
+public class ThreeWayQuickSort {
+
+    public static void threeWayQuickSort(int[] a, int begin, int end)
+    {
+        if (end <= begin) return;
+
+        // partition
+        int i = begin;
+        int less = begin;
+        int greater = end;
+
+        while (i <= greater){
+            if (a[i] < a[less]) {
+                int tmp = a[i];
+                a[i] = a[less];
+                a[less] = tmp;
+
+                i++;
+                less++;
+            }
+            else if (a[less] < a[i])	{
+                int tmp = a[i];
+                a[i] = a[greater];
+                a[greater] = tmp;
+
+                greater--;
+            }
+            else {
+                i++;
+            }
+        }
+
+        threeWayQuickSort(a, begin, less - 1);
+        threeWayQuickSort(a, greater + 1, end);
+    }
+}

algorithms/src/test/java/com/baeldung/algorithms/quicksort/QuickSortUnitTest.java

@@ -0,0 +1,17 @@
+package com.baeldung.algorithms.quicksort;
+
+import com.baeldung.algorithms.quicksort.QuickSort;
+import org.junit.Assert;
+import org.junit.Test;
+
+public class QuickSortUnitTest {
+
+    @Test
+    public void givenIntegerArray_whenSortedWithQuickSort_thenGetSortedArray() {
+        int[] actual = { 9, 5, 1, 0, 6, 2, 3, 4, 7, 8 };
+        int[] expected = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 };
+        QuickSort.quickSort(actual, 0, actual.length-1);
+        Assert.assertArrayEquals(expected, actual);
+    }
+
+}

algorithms/src/test/java/com/baeldung/algorithms/quicksort/ThreeWayQuickSortUnitTest.java

@@ -0,0 +1,15 @@
+package com.baeldung.algorithms.quicksort;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+public class ThreeWayQuickSortUnitTest {
+
+    @Test
+    public void givenIntegerArray_whenSortedWithThreeWayQuickSort_thenGetSortedArray() {
+        int[] actual = { 3, 5, 5, 5, 3, 7, 7, 3, 5, 5, 7, 3, 3 };
+        int[] expected = { 3, 3, 3, 3, 3, 5, 5, 5, 5, 5, 7, 7, 7 };
+        ThreeWayQuickSort.threeWayQuickSort(actual, 0, actual.length-1);
+        Assert.assertArrayEquals(expected, actual);
+    }
+}

apache-geode/pom.xml

@@ -0,0 +1,46 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+
+    <groupId>com.baeldung</groupId>
+    <artifactId>apache-geode</artifactId>
+    <version>1.0-SNAPSHOT</version>
+
+    <parent>
+        <groupId>com.baeldung</groupId>
+        <artifactId>parent-modules</artifactId>
+        <version>1.0.0-SNAPSHOT</version>
+    </parent>
+    
+    <properties>
+        <geode.core>1.6.0</geode.core>
+    </properties>
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-compiler-plugin</artifactId>
+                <configuration>
+                    <source>1.8</source>
+                    <target>1.8</target>
+                </configuration>
+            </plugin>
+        </plugins>
+    </build>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.apache.geode</groupId>
+            <artifactId>geode-core</artifactId>
+            <version>${geode.core}</version>
+        </dependency>
+        <dependency>
+            <groupId>junit</groupId>
+            <artifactId>junit</artifactId>
+            <version>RELEASE</version>
+        </dependency>
+    </dependencies>
+    
+</project>

apache-geode/src/main/java/com/baeldung/geode/Customer.java

@@ -0,0 +1,78 @@
+package com.baeldung.geode;
+
+import java.io.Serializable;
+import java.util.Objects;
+
+public class Customer implements Serializable {
+
+    private static final long serialVersionUID = -7482516011038799900L;
+
+    private CustomerKey key;
+    private String firstName;
+    private String lastName;
+    private Integer age;
+
+    public Customer() {
+    }
+
+    public Customer(String firstName, String lastName, int age) {
+        this.firstName = firstName;
+        this.lastName = lastName;
+        this.age = age;
+    }
+
+    public Customer(CustomerKey key, String firstName, String lastName, int age) {
+        this(firstName, lastName, age);
+        this.key = key;
+    }
+
+    // setters and getters
+
+    public static long getSerialVersionUID() {
+        return serialVersionUID;
+    }
+
+    public String getFirstName() {
+        return firstName;
+    }
+
+    public void setFirstName(String firstName) {
+        this.firstName = firstName;
+    }
+
+    public String getLastName() {
+        return lastName;
+    }
+
+    public void setLastName(String lastName) {
+        this.lastName = lastName;
+    }
+
+    public Integer getAge() {
+        return age;
+    }
+
+    public void setAge(Integer age) {
+        this.age = age;
+    }
+
+    @Override
+    public String toString() {
+        return "Customer{" + "firstName='" + firstName + '\'' + ", lastName='" + lastName + '\'' + ", age=" + age + '}';
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o)
+            return true;
+        if (o == null || getClass() != o.getClass())
+            return false;
+        Customer customer = (Customer) o;
+        return Objects.equals(firstName, customer.firstName) && Objects.equals(lastName, customer.lastName) && Objects.equals(age, customer.age);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(firstName, lastName, age);
+    }
+}

apache-geode/src/main/java/com/baeldung/geode/CustomerKey.java

@@ -0,0 +1,57 @@
+package com.baeldung.geode;
+
+import java.io.Serializable;
+
+public class CustomerKey implements Serializable {
+
+    private static final long serialVersionUID = -3529253035303792458L;
+    private long id;
+    private String country;
+
+    public CustomerKey(long id) {
+        this.id = id;
+        this.country = "USA";
+    }
+
+    public CustomerKey(long id, String country) {
+        this.id = id;
+        this.country = country;
+    }
+
+    public long getId() {
+        return id;
+    }
+
+    public void setId(long id) {
+        this.id = id;
+    }
+
+    public String getCountry() {
+        return country;
+    }
+
+    public void setCountry(String country) {
+        this.country = country;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o)
+            return true;
+        if (o == null || getClass() != o.getClass())
+            return false;
+
+        CustomerKey that = (CustomerKey) o;
+
+        if (id != that.id)
+            return false;
+        return country != null ? country.equals(that.country) : that.country == null;
+    }
+
+    @Override
+    public int hashCode() {
+        int result = (int) (id ^ (id >>> 32));
+        result = 31 * result + (country != null ? country.hashCode() : 0);
+        return result;
+    }
+}

apache-geode/src/main/java/com/baeldung/geode/functions/UpperCaseNames.java

@@ -0,0 +1,34 @@
+package com.baeldung.geode.functions;
+
+import com.baeldung.geode.Customer;
+import com.baeldung.geode.CustomerKey;
+import org.apache.geode.cache.Region;
+import org.apache.geode.cache.execute.Function;
+import org.apache.geode.cache.execute.FunctionContext;
+import org.apache.geode.cache.execute.RegionFunctionContext;
+
+import java.util.Map;
+
+public class UpperCaseNames implements Function<Boolean> {
+    private static final long serialVersionUID = -8946294032165677602L;
+
+    @Override
+    public void execute(FunctionContext<Boolean> context) {
+        RegionFunctionContext regionContext = (RegionFunctionContext) context;
+        Region<CustomerKey, Customer> region = regionContext.getDataSet();
+
+        for (Map.Entry<CustomerKey, Customer> entry : region.entrySet()) {
+            Customer customer = entry.getValue();
+            customer.setFirstName(customer.getFirstName()
+                .toUpperCase());
+        }
+
+        context.getResultSender()
+            .lastResult(true);
+    }
+
+    @Override
+    public String getId() {
+        return getClass().getName();
+    }
+}

apache-geode/src/test/java/com/baeldung/geode/GeodeSamplesIntegrationTest.java

@@ -0,0 +1,110 @@
+package com.baeldung.geode;
+
+import com.baeldung.geode.functions.UpperCaseNames;
+import org.apache.geode.cache.Region;
+import org.apache.geode.cache.client.ClientCache;
+import org.apache.geode.cache.client.ClientCacheFactory;
+import org.apache.geode.cache.client.ClientRegionShortcut;
+import org.apache.geode.cache.execute.Execution;
+import org.apache.geode.cache.execute.FunctionService;
+import org.apache.geode.cache.query.*;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+
+import java.util.HashMap;
+import java.util.Map;
+import java.util.function.Function;
+import java.util.function.Supplier;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
+
+import static org.junit.Assert.assertEquals;
+
+public class GeodeSamplesIntegrationTest {
+
+    ClientCache cache = null;
+    Region<String, String> region = null;
+    Region<Integer, Customer> queryRegion = null;
+    Region<CustomerKey, Customer> customerRegion = null;
+
+    @Before
+    public void connect() {
+        this.cache = new ClientCacheFactory().addPoolLocator("localhost", 10334)
+            .create();
+        this.region = this.cache.<String, String> createClientRegionFactory(ClientRegionShortcut.CACHING_PROXY)
+            .create("baeldung");
+        this.customerRegion = this.cache.<CustomerKey, Customer> createClientRegionFactory(ClientRegionShortcut.CACHING_PROXY)
+            .create("baeldung-customers");
+    }
+
+    @After
+    public void cleanup() {
+        this.cache.close();
+    }
+
+    @Test
+    public void whenSendMessageToRegion_thenMessageSavedSuccessfully() {
+
+        this.region.put("1", "Hello");
+        this.region.put("2", "Baeldung");
+
+        assertEquals("Hello", region.get("1"));
+        assertEquals("Baeldung", region.get("2"));
+
+    }
+
+    @Test
+    public void whenPutMultipleValuesAtOnce_thenValuesSavedSuccessfully() {
+
+        Supplier<Stream<String>> keys = () -> Stream.of("A", "B", "C", "D", "E");
+        Map<String, String> values = keys.get()
+            .collect(Collectors.toMap(Function.identity(), String::toLowerCase));
+
+        this.region.putAll(values);
+
+        keys.get()
+            .forEach(k -> assertEquals(k.toLowerCase(), this.region.get(k)));
+
+    }
+
+    @Test
+    public void whenPutCustomKey_thenValuesSavedSuccessfully() {
+        CustomerKey key = new CustomerKey(123);
+        Customer customer = new Customer(key, "William", "Russell", 35);
+
+        Map<CustomerKey, Customer> customerInfo = new HashMap<>();
+        customerInfo.put(key, customer);
+
+        this.customerRegion.putAll(customerInfo);
+
+        Customer storedCustomer = this.customerRegion.get(key);
+        assertEquals("William", storedCustomer.getFirstName());
+        assertEquals("Russell", storedCustomer.getLastName());
+
+    }
+
+    @Test
+    public void whenFindACustomerUsingOQL_thenCorrectCustomerObject() throws NameResolutionException, TypeMismatchException, QueryInvocationTargetException, FunctionDomainException {
+
+        Map<CustomerKey, Customer> data = new HashMap<>();
+        data.put(new CustomerKey(1), new Customer("Gheorge", "Manuc", 36));
+        data.put(new CustomerKey(2), new Customer("Allan", "McDowell", 43));
+        this.customerRegion.putAll(data);
+
+        QueryService queryService = this.cache.getQueryService();
+        String query = "select * from /baeldung-customers c where c.firstName = 'Allan'";
+        SelectResults<Customer> queryResults = (SelectResults<Customer>) queryService.newQuery(query)
+            .execute();
+        assertEquals(1, queryResults.size());
+
+    }
+
+    @Test
+    public void whenExecuteUppercaseNames_thenCustomerNamesAreUppercased() {
+        Execution execution = FunctionService.onRegion(this.customerRegion);
+        execution.execute(UpperCaseNames.class.getName());
+        Customer customer = this.customerRegion.get(new CustomerKey(1));
+        assertEquals("GHEORGE", customer.getFirstName());
+    }
+}

core-java-8/src/test/java/com/baeldung/java8/Java8SortUnitTest.java

@@ -1,16 +1,18 @@
 package com.baeldung.java8;
 
-import com.baeldung.java8.entity.Human;
+import static org.hamcrest.Matchers.equalTo;
-import com.google.common.collect.Lists;
-import com.google.common.primitives.Ints;
-import org.junit.Assert;
-import org.junit.Test;
 
 import java.util.Collections;
 import java.util.Comparator;
 import java.util.List;
+import java.util.stream.Collectors;
 
-import static org.hamcrest.Matchers.equalTo;
+import org.junit.Assert;
+import org.junit.Test;
+
+import com.baeldung.java8.entity.Human;
+import com.google.common.collect.Lists;
+import com.google.common.primitives.Ints;
 
 public class Java8SortUnitTest {
 
@@ -112,4 +114,21 @@ public class Java8SortUnitTest {
         Assert.assertThat(humans.get(0), equalTo(new Human("Jack", 12)));
     }
     
+    @Test
+    public final void givenStreamNaturalOrdering_whenSortingEntitiesByName_thenCorrectlySorted() {
+        final List<String> letters = Lists.newArrayList("B", "A", "C");
+        
+        final List<String> sortedLetters = letters.stream().sorted().collect(Collectors.toList());
+        Assert.assertThat(sortedLetters.get(0), equalTo("A"));
+    }
+
+    @Test
+    public final void givenStreamCustomOrdering_whenSortingEntitiesByName_thenCorrectlySorted() {
+        
+        final List<Human> humans = Lists.newArrayList(new Human("Sarah", 10), new Human("Jack", 12));
+        final Comparator<Human> nameComparator = (h1, h2) -> h1.getName().compareTo(h2.getName());
+        
+        final List<Human> sortedHumans = humans.stream().sorted(nameComparator).collect(Collectors.toList());
+        Assert.assertThat(sortedHumans.get(0), equalTo(new Human("Jack", 12)));
+    }
 }

core-java-8/src/test/java/com/baeldung/stream/conditional/StreamForEachIfElseUnitTest.java

@@ -0,0 +1,41 @@
+package com.baeldung.stream.conditional;
+
+import java.util.Arrays;
+import java.util.List;
+import java.util.stream.Stream;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+public class StreamForEachIfElseUnitTest {
+
+    @Test
+    public final void givenIntegerStream_whenCheckingIntegerParityWithIfElse_thenEnsureCorrectParity() {
+        List<Integer> ints = Arrays.asList(1, 2, 3, 4, 5, 6, 7, 8, 9, 10);
+
+        ints.stream()
+            .forEach(i -> {
+                if (i.intValue() % 2 == 0) {
+                    Assert.assertTrue(i.intValue() + " is not even", i.intValue() % 2 == 0);
+                } else {
+                    Assert.assertTrue(i.intValue() + " is not odd", i.intValue() % 2 != 0);
+                }
+            });
+
+    }
+
+    @Test
+    public final void givenIntegerStream_whenCheckingIntegerParityWithStreamFilter_thenEnsureCorrectParity() {
+        List<Integer> ints = Arrays.asList(1, 2, 3, 4, 5, 6, 7, 8, 9, 10);
+
+        Stream<Integer> evenIntegers = ints.stream()
+            .filter(i -> i.intValue() % 2 == 0);
+        Stream<Integer> oddIntegers = ints.stream()
+            .filter(i -> i.intValue() % 2 != 0);
+
+        evenIntegers.forEach(i -> Assert.assertTrue(i.intValue() + " is not even", i.intValue() % 2 == 0));
+        oddIntegers.forEach(i -> Assert.assertTrue(i.intValue() + " is not odd", i.intValue() % 2 != 0));
+
+    }
+
+}

core-java/README.md

@@ -25,7 +25,6 @@
 - [The Traveling Salesman Problem in Java](http://www.baeldung.com/java-simulated-annealing-for-traveling-salesman)
 - [How to Create an Executable JAR with Maven](http://www.baeldung.com/executable-jar-with-maven)
 - [How to Design a Genetic Algorithm in Java](http://www.baeldung.com/java-genetic-algorithm)
-- [Spring Security – Cache Control Headers](http://www.baeldung.com/spring-security-cache-control-headers)
 - [Basic Introduction to JMX](http://www.baeldung.com/java-management-extensions)
 - [AWS Lambda With Java](http://www.baeldung.com/java-aws-lambda)
 - [Introduction to Nashorn](http://www.baeldung.com/java-nashorn)

core-java/src/main/java/com/baeldung/memoryleaks/equalshashcode/Person.java

@@ -0,0 +1,9 @@
+package com.baeldung.memoryleaks.equalshashcode;
+
+public class Person {
+    public String name;
+     
+    public Person(String name) {
+        this.name = name;
+    }
+}

core-java/src/main/java/com/baeldung/memoryleaks/equalshashcode/PersonOptimized.java

@@ -0,0 +1,25 @@
+package com.baeldung.memoryleaks.equalshashcode;
+
+public class PersonOptimized {
+    public String name;
+     
+    public PersonOptimized(String name) {
+        this.name = name;
+    }
+     
+    @Override
+    public boolean equals(Object o) {
+        if (o == this) return true;
+        if (!(o instanceof PersonOptimized)) {
+            return false;
+        }
+        PersonOptimized person = (PersonOptimized) o;
+        return person.name.equals(name);
+    }
+     
+    @Override
+    public int hashCode() {
+        int result = 17;
+        result = 31 * result + name.hashCode();
+        return result;
+    }}

core-java/src/main/java/com/baeldung/memoryleaks/finalize/BulkyObject.java

@@ -0,0 +1,32 @@
+package com.baeldung.memoryleaks.finalize;
+
+import java.nio.charset.Charset;
+import java.util.Random;
+
+public class BulkyObject {
+    private String data[];
+    
+    public BulkyObject() {
+        data = new String[1000000];
+        
+        for(int i=0; i<1000000; i++) {
+            data[i] = getRandomString();
+        }
+    }
+    
+    private String getRandomString() {
+        byte[] array = new byte[1000];
+        new Random().nextBytes(array);
+        return new String(array, Charset.forName("UTF-8"));
+    }
+    
+    @Override
+    public void finalize() {
+        try {
+            Thread.sleep(100);
+        } catch (InterruptedException e) {
+            e.printStackTrace();
+        }
+        System.out.println("Finalizer called");
+    }
+}

core-java/src/main/java/com/baeldung/memoryleaks/finalize/BulkyObjectOptimized.java

@@ -0,0 +1,22 @@
+package com.baeldung.memoryleaks.finalize;
+
+import java.nio.charset.Charset;
+import java.util.Random;
+
+public class BulkyObjectOptimized {
+    private String data[];
+    
+    public BulkyObjectOptimized() {
+        data = new String[1000000];
+        
+        for(int i=0; i<1000000; i++) {
+            data[i] = getRandomString();
+        }
+    }
+    
+    private String getRandomString() {
+        byte[] array = new byte[1000];
+        new Random().nextBytes(array);
+        return new String(array, Charset.forName("UTF-8"));
+    }
+}

core-java/src/main/java/com/baeldung/memoryleaks/innerclass/BulkyObject.java

@@ -0,0 +1,22 @@
+package com.baeldung.memoryleaks.innerclass;
+
+import java.nio.charset.Charset;
+import java.util.Random;
+
+public class BulkyObject {
+    private String data[];
+    
+    public BulkyObject() {
+        data = new String[1000000];
+        
+        for(int i=0; i<1000000; i++) {
+            data[i] = getRandomString();
+        }
+    }
+    
+    private String getRandomString() {
+        byte[] array = new byte[1000];
+        new Random().nextBytes(array);
+        return new String(array, Charset.forName("UTF-8"));
+    }
+}

core-java/src/main/java/com/baeldung/memoryleaks/innerclass/InnerClassDriver.java

@@ -0,0 +1,17 @@
+package com.baeldung.memoryleaks.innerclass;
+
+public class InnerClassDriver {
+    public static InnerClassWrapper.SimpleInnerClass getSimpleInnerClassObj() {
+        return new InnerClassWrapper().new SimpleInnerClass();
+    }
+    
+    public static void main2(String[] args) {
+        InnerClassWrapper.SimpleInnerClass simpleInnerClassObj = getSimpleInnerClassObj();
+        System.out.println("Debug point");
+    }
+    
+    public static void main(String[] args) {
+        StaticNestedClassWrapper.StaticNestedClass simpleInnerClassObj = new StaticNestedClassWrapper.StaticNestedClass();
+        System.out.println("Debug point");
+    }
+}

core-java/src/main/java/com/baeldung/memoryleaks/innerclass/InnerClassWrapper.java

@@ -0,0 +1,10 @@
+package com.baeldung.memoryleaks.innerclass;
+
+
+public class InnerClassWrapper {
+    private BulkyObject bulkyObject = new BulkyObject();
+    
+    public class SimpleInnerClass {
+        
+    }
+}

core-java/src/main/java/com/baeldung/memoryleaks/innerclass/StaticNestedClassWrapper.java

@@ -0,0 +1,10 @@
+package com.baeldung.memoryleaks.innerclass;
+
+
+public class StaticNestedClassWrapper {
+    private BulkyObject bulkyObject = new BulkyObject();
+    
+    public static class StaticNestedClass {
+        
+    }
+}

core-java/src/main/java/com/baeldung/memoryleaks/internedstrings/InternedString.java

@@ -0,0 +1,17 @@
+package com.baeldung.memoryleaks.internedstrings;
+
+public class InternedString {
+    private static final String FILEPATH = "C:\\bigstring.txt";
+    
+    public void readString() {
+        String s1 = ReadStringFromFileUtil.read(FILEPATH).intern();
+        String s2 = ReadStringFromFileUtil.read(FILEPATH).intern();
+
+        if (s1 == s2) {
+            System.out.println("Both the strings objects are same");
+        }
+        else {
+            System.out.println("Both the strings objects are different");
+        }
+    }
+}

core-java/src/main/java/com/baeldung/memoryleaks/internedstrings/ReadStringFromFileUtil.java

@@ -0,0 +1,34 @@
+package com.baeldung.memoryleaks.internedstrings;
+
+import java.io.BufferedReader;
+import java.io.FileReader;
+import java.io.IOException;
+
+public class ReadStringFromFileUtil {
+
+    public static String read(String fileName) {
+        BufferedReader br = null;
+        try {
+            br = new BufferedReader(new FileReader(fileName));
+            StringBuilder sb = new StringBuilder();
+            String line = br.readLine();
+
+            while (line != null) {
+                sb.append(line);
+                sb.append("\n");
+                line = br.readLine();
+            }
+            return sb.toString();
+        } catch (IOException e) {
+            e.printStackTrace();
+        } finally {
+            try {
+                br.close();
+            } catch (IOException e) {
+                e.printStackTrace();
+            }
+        }
+        return null;
+    }
+
+}

core-java/src/main/java/com/baeldung/memoryleaks/internedstrings/StringObject.java

@@ -0,0 +1,17 @@
+package com.baeldung.memoryleaks.internedstrings;
+
+public class StringObject {
+    private static final String FILEPATH = "C:\\bigstring.txt";
+    
+    public void readString() {
+        String s1 = ReadStringFromFileUtil.read(FILEPATH);
+        String s2 = ReadStringFromFileUtil.read(FILEPATH);
+
+        if (s1 == s2) {
+            System.out.println("Both the strings objects are same");
+        }
+        else {
+            System.out.println("Both the strings objects are different");
+        }
+    }
+}

core-java/src/main/java/com/baeldung/memoryleaks/staticfields/NonStaticFieldsDemo.java

@@ -0,0 +1,21 @@
+package com.baeldung.memoryleaks.staticfields;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class NonStaticFieldsDemo {
+    public List<Double> list = new ArrayList<>();
+ 
+    public void populateList() {
+        for (int i = 0; i < 10000000; i++) {
+            list.add(Math.random());
+        }
+        System.out.println("Debug Point 2");
+    }
+ 
+    public static void main(String[] args) {
+        System.out.println("Debug Point 1");
+        new NonStaticFieldsDemo().populateList();
+        System.out.println("Debug Point 3");
+    }
+}

core-java/src/main/java/com/baeldung/memoryleaks/staticfields/StaticFieldsDemo.java

@@ -0,0 +1,21 @@
+package com.baeldung.memoryleaks.staticfields;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class StaticFieldsDemo {
+    public static List<Double> list = new ArrayList<>();
+ 
+    public void populateList() {
+        for (int i = 0; i < 10000000; i++) {
+            list.add(Math.random());
+        }
+        System.out.println("Debug Point 2");
+    }
+ 
+    public static void main(String[] args) {
+        System.out.println("Debug Point 1");
+        new StaticFieldsDemo().populateList();
+        System.out.println("Debug Point 3");
+    }
+}

core-java/src/main/java/com/baeldung/nth/root/calculator/NthRootCalculator.java

@@ -0,0 +1,8 @@
+package com.baeldung.nth.root.calculator;
+
+public class NthRootCalculator
+{
+    public Double calculate(Double base, Double n) {
+        return Math.pow(Math.E, Math.log(base)/n);
+    }
+}

core-java/src/main/java/com/baeldung/nth/root/main/Main.java

@@ -0,0 +1,13 @@
+package com.baeldung.nth.root.main;
+
+import com.baeldung.nth.root.calculator.NthRootCalculator;
+
+public class Main {
+    public static void main(String[] args) {
+        NthRootCalculator calculator = new NthRootCalculator();
+        Double base = Double.parseDouble(args[0]);
+        Double n = Double.parseDouble(args[1]);
+        Double result = calculator.calculate(base, n);
+        System.out.println("The " + n + " root of " + base + " equals to " + result + ".");
+    }
+}

core-java/src/test/java/com/baeldung/memoryleaks/equalshashcode/PersonMemoryLeakUnitTest.java

@@ -0,0 +1,33 @@
+package com.baeldung.memoryleaks.equalshashcode;
+
+import static org.junit.Assert.assertTrue;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import org.junit.Ignore;
+import org.junit.Test;
+
+public class PersonMemoryLeakUnitTest {
+    @Test
+    @Ignore // Test deliberately ignored as memory leak tests consume lots of resources
+    public void givenMap_whenEqualsAndHashCodeNotOverridden_thenMemoryLeak() {
+        Map<Person, Integer> map = new HashMap<Person, Integer>();
+        for(int i=0; i<10000000; i++) {
+            map.put(new Person("jon"), 1);
+        }
+        assertTrue(map.size() > 1);
+        System.out.print("Debug Point - VisuaLVM");
+    }
+    
+    @Test
+    @Ignore // Test deliberately ignored as memory leak tests consume lots of resources
+    public void givenMap_whenEqualsAndHashCodeOverridden_thenNoMemoryLeak() {
+        Map<PersonOptimized, Integer> map = new HashMap<PersonOptimized, Integer>();
+        for(int i=0; i<10000; i++) {
+            map.put(new PersonOptimized("jon"), 1);
+        }
+        assertTrue(map.size() == 1);
+        System.out.print("Debug Point - VisuaLVM");
+    }
+}

core-java/src/test/java/com/baeldung/memoryleaks/finalize/FinalizeMemoryLeakUnitTest.java

@@ -0,0 +1,28 @@
+package com.baeldung.memoryleaks.finalize;
+
+import org.junit.Ignore;
+import org.junit.Test;
+
+public class FinalizeMemoryLeakUnitTest {
+    @Test
+    @Ignore // Test deliberately ignored as memory leak tests consume lots of resources
+    public void givenObjectWithFinalizer_whenCreatingAndDestroyingThisObject_thenMemoryLeak() {
+        BulkyObject[] stock = new BulkyObject[100000];
+        
+        for(int i=0; i<100000; i++) {
+            stock[i] = new BulkyObject();
+        }
+        System.out.print("Debug Point - VisuaLVM");
+    }
+    
+    @Test
+    @Ignore // Test deliberately ignored as memory leak tests consume lots of resources
+    public void givenObjectWithoutFinalizer_whenCreatingAndDestroyingThisObject_thenNoMemoryLeak() {
+        BulkyObjectOptimized[] stock = new BulkyObjectOptimized[100000];
+        
+        for(int i=0; i<100000; i++) {
+            stock[i] = new BulkyObjectOptimized();
+        }
+        System.out.print("Debug Point - VisuaLVM");
+    }
+}

core-java/src/test/java/com/baeldung/memoryleaks/innerclass/StaticInnerClassMemoryLeakUnitTest.java

@@ -0,0 +1,20 @@
+package com.baeldung.memoryleaks.innerclass;
+
+import org.junit.Ignore;
+import org.junit.Test;
+
+public class StaticInnerClassMemoryLeakUnitTest {
+    @Test
+    @Ignore // Test deliberately ignored as memory leak tests consume lots of resources
+    public void givenUsingInnerClass_whenInitializingInnerClass_thenInnerClassHoldsReferenceOfOuterObject() {
+        InnerClassWrapper.SimpleInnerClass simpleInnerClassObj = new InnerClassWrapper().new SimpleInnerClass();
+        System.out.print("Debug Point - VisuaLVM");
+    }
+    
+    @Test
+    @Ignore // Test deliberately ignored as memory leak tests consume lots of resources
+    public void givenUsingStaticNestedClass_whenInitializingInnerClass_thenStaticNestedClassDoesntReferenceOuterObject() {
+        StaticNestedClassWrapper.StaticNestedClass staticNestedClassObj = new StaticNestedClassWrapper.StaticNestedClass();
+        System.out.print("Debug Point - VisuaLVM");
+    }
+}

core-java/src/test/java/com/baeldung/memoryleaks/internedstrings/StringInternMemoryLeakUnitTest.java

@@ -0,0 +1,20 @@
+package com.baeldung.memoryleaks.internedstrings;
+
+import org.junit.Ignore;
+import org.junit.Test;
+
+public class StringInternMemoryLeakUnitTest {
+    @Test
+    @Ignore // Test deliberately ignored as memory leak tests consume lots of resources
+    public void givenJava6OrBelow_whenInterningLargeStrings_thenPermgenIncreases() {
+        new InternedString().readString();
+        System.out.print("Debug Point - VisuaLVM");
+    }
+    
+    @Test
+    @Ignore // Test deliberately ignored as memory leak tests consume lots of resources
+    public void givenJava6OrBelow_whenNotInterningLargeStrings_thenPermgenDoesntIncrease() {
+        new StringObject().readString();
+        System.out.print("Debug Point - VisuaLVM");
+    }
+}

core-java/src/test/java/com/baeldung/memoryleaks/staticfields/NonStaticFieldsMemoryLeakUnitTest.java

@@ -0,0 +1,26 @@
+package com.baeldung.memoryleaks.staticfields;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import org.junit.Ignore;
+import org.junit.Test;
+
+public class NonStaticFieldsMemoryLeakUnitTest {
+    public List<Double> list = new ArrayList<>();
+ 
+    public void populateList() {
+        for (int i = 0; i < 10000000; i++) {
+            list.add(Math.random());
+        }
+        System.out.println("Debug Point 2");
+    }
+ 
+    @Test
+    @Ignore // Test deliberately ignored as memory leak tests consume lots of resources
+    public void givenNonStaticLargeList_whenPopulatingList_thenListGarbageCollected() {
+        System.out.println("Debug Point 1");
+        new NonStaticFieldsMemoryLeakUnitTest().populateList();
+        System.out.println("Debug Point 3");
+    }
+}

core-java/src/test/java/com/baeldung/memoryleaks/staticfields/StaticFieldsMemoryLeakUnitTest.java

@@ -0,0 +1,26 @@
+package com.baeldung.memoryleaks.staticfields;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import org.junit.Ignore;
+import org.junit.Test;
+
+public class StaticFieldsMemoryLeakUnitTest {
+    public static List<Double> list = new ArrayList<>();
+ 
+    public void populateList() {
+        for (int i = 0; i < 10000000; i++) {
+            list.add(Math.random());
+        }
+        System.out.println("Debug Point 2");
+    }
+ 
+    @Test
+    @Ignore // Test deliberately ignored as memory leak tests consume lots of resources
+    public void givenStaticLargeList_whenPopulatingList_thenListIsNotGarbageCollected() {
+        System.out.println("Debug Point 1");
+        new StaticFieldsDemo().populateList();
+        System.out.println("Debug Point 3");
+    }
+}

core-java/src/test/java/com/baeldung/nth/root/calculator/NthRootCalculatorUnitTest.java

@@ -0,0 +1,21 @@
+package com.baeldung.nth.root.calculator;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.InjectMocks;
+import org.mockito.runners.MockitoJUnitRunner;
+
+import static org.junit.Assert.assertEquals;
+
+@RunWith(MockitoJUnitRunner.class)
+public class NthRootCalculatorUnitTest {
+
+    @InjectMocks
+    private NthRootCalculator nthRootCalculator;
+
+    @Test
+    public void giventThatTheBaseIs125_andTheExpIs3_whenCalculateIsCalled_thenTheResultIsTheCorrectOne() {
+       Double result = nthRootCalculator.calculate(125.0, 3.0);
+       assertEquals(result, (Double) 5.0d);
+    }
+}

core-java/src/test/java/com/baeldung/nth/root/main/MainUnitTest.java

@@ -0,0 +1,34 @@
+package com.baeldung.nth.root.main;
+
+import java.io.ByteArrayOutputStream;
+import java.io.PrintStream;
+
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+import org.mockito.InjectMocks;
+import static org.junit.Assert.assertEquals;
+
+public class MainUnitTest {
+    @InjectMocks
+    private Main main;
+
+    private final ByteArrayOutputStream outContent = new ByteArrayOutputStream();
+    private final PrintStream originalOut = System.out;
+
+    @Before
+    public void setUpStreams() {
+        System.setOut(new PrintStream(outContent));
+    }
+
+    @After
+    public void restoreStreams() {
+        System.setOut(originalOut);
+    }
+
+    @Test
+    public void givenThatTheBaseIs125_andTheExpIs3_whenMainIsCalled_thenTheCorrectResultIsPrinted() {
+        main.main(new String[]{"125.0", "3.0"});
+        assertEquals("The 3.0 root of 125.0 equals to 5.0.\n", outContent.toString().replaceAll("\r", ""));
+    }
+}

core-kotlin/src/test/kotlin/com/baeldung/kotlin/StructuralJumpUnitTest.kt

@@ -0,0 +1,121 @@
+package com.baeldung.kotlin
+
+import org.junit.Test
+import kotlin.test.assertEquals
+import kotlin.test.assertFalse
+
+class StructuralJumpUnitTest {
+
+    @Test
+    fun givenLoop_whenBreak_thenComplete() {
+        var value = ""
+        for (i in "hello_world") {
+            if (i == '_')
+                break
+            value += i.toString()
+        }
+        assertEquals("hello", value)
+    }
+    @Test
+    fun givenLoop_whenBreakWithLabel_thenComplete() {
+        var value = ""
+        outer_loop@ for (i in 'a'..'d') {
+            for (j in 1..3) {
+                value += "" + i + j
+                if (i == 'b' && j == 1)
+                    break@outer_loop
+            }
+        }
+        assertEquals("a1a2a3b1", value)
+    }
+
+    @Test
+    fun givenLoop_whenContinue_thenComplete() {
+        var result = ""
+        for (i in "hello_world") {
+            if (i == '_')
+                continue
+            result += i
+        }
+        assertEquals("helloworld", result)
+    }
+    @Test
+    fun givenLoop_whenContinueWithLabel_thenComplete() {
+        var result = ""
+        outer_loop@ for (i in 'a'..'c') {
+            for (j in 1..3) {
+                if (i == 'b')
+                    continue@outer_loop
+                result += "" + i + j
+            }
+        }
+        assertEquals("a1a2a3c1c2c3", result)
+    }
+
+    @Test
+    fun givenLambda_whenReturn_thenComplete() {
+        var result = returnInLambda();
+        assertEquals("hello", result)
+    }
+
+    private fun returnInLambda(): String {
+        var result = ""
+        "hello_world".forEach {
+            // non-local return directly to the caller
+            if (it == '_') return result
+            result += it.toString()
+        }
+        //this line won't be reached
+        return result;
+    }
+
+    @Test
+    fun givenLambda_whenReturnWithExplicitLabel_thenComplete() {
+        var result = ""
+        "hello_world".forEach lit@{
+            if (it == '_') {
+                // local return to the caller of the lambda, i.e. the forEach loop
+                return@lit
+            }
+            result += it.toString()
+        }
+        assertEquals("helloworld", result)
+    }
+
+    @Test
+    fun givenLambda_whenReturnWithImplicitLabel_thenComplete() {
+        var result = ""
+        "hello_world".forEach {
+            if (it == '_') {
+                // local return to the caller of the lambda, i.e. the forEach loop
+                return@forEach
+            }
+            result += it.toString()
+        }
+        assertEquals("helloworld", result)
+    }
+
+    @Test
+    fun givenAnonymousFunction_return_thenComplete() {
+        var result = ""
+        "hello_world".forEach(fun(element) {
+            // local return to the caller of the anonymous fun, i.e. the forEach loop
+            if (element == '_') return
+            result += element.toString()
+        })
+        assertEquals("helloworld", result)
+    }
+
+    @Test
+    fun givenAnonymousFunction_returnToLabel_thenComplete() {
+        var result = ""
+        run loop@{
+            "hello_world".forEach {
+                // non-local return from the lambda passed to run
+                if (it == '_') return@loop
+                result += it.toString()
+            }
+        }
+        assertEquals("hello", result)
+    }
+}

flyway-cdi-extension/pom.xml

@@ -0,0 +1,51 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+
+    <groupId>com.baeldung</groupId>
+    <artifactId>flyway-cdi-extension</artifactId>
+    <version>1.0-SNAPSHOT</version>
+
+    <properties>
+        <maven.compiler.source>1.8</maven.compiler.source>
+        <maven.compiler.target>1.8</maven.compiler.target>
+    </properties>
+
+    <dependencies>
+        <dependency>
+            <groupId>javax.enterprise</groupId>
+            <artifactId>cdi-api</artifactId>
+            <version>2.0.SP1</version>
+        </dependency>
+        <dependency>
+            <groupId>org.jboss.weld.se</groupId>
+            <artifactId>weld-se-core</artifactId>
+            <version>3.0.5.Final</version>
+            <scope>runtime</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.flywaydb</groupId>
+            <artifactId>flyway-core</artifactId>
+            <version>5.1.4</version>
+        </dependency>
+        <dependency>
+            <groupId>org.apache.tomcat</groupId>
+            <artifactId>tomcat-jdbc</artifactId>
+            <version>8.5.33</version>
+        </dependency>
+        <dependency>
+            <groupId>javax.annotation</groupId>
+            <artifactId>javax.annotation-api</artifactId>
+            <version>1.3.2</version>
+        </dependency>
+        <dependency>
+            <groupId>com.h2database</groupId>
+            <artifactId>h2</artifactId>
+            <version>1.4.197</version>
+            <scope>runtime</scope>
+        </dependency>
+    </dependencies>
+
+</project>

flyway-cdi-extension/src/main/java/com/baeldung/cdi/extension/FlywayExtension.java

@@ -0,0 +1,74 @@
+package com.baeldung.cdi.extension;
+
+import org.apache.tomcat.jdbc.pool.DataSource;
+import org.flywaydb.core.Flyway;
+
+import javax.annotation.sql.DataSourceDefinition;
+import javax.enterprise.context.ApplicationScoped;
+import javax.enterprise.event.Observes;
+import javax.enterprise.inject.Any;
+import javax.enterprise.inject.Default;
+import javax.enterprise.inject.literal.InjectLiteral;
+import javax.enterprise.inject.spi.*;
+import javax.enterprise.util.AnnotationLiteral;
+
+
+/**
+ * Flyway is now under CDI container like:
+ *
+ * @ApplicationScoped
+ * @FlywayType public class Flyway{
+ * @Inject setDataSource(DataSource dataSource){
+ * //...
+ * }
+ * }
+ */
+
+public class FlywayExtension implements Extension {
+
+    DataSourceDefinition dataSourceDefinition = null;
+
+    public void registerFlywayType(@Observes BeforeBeanDiscovery bbdEvent) {
+        bbdEvent.addAnnotatedType(Flyway.class, Flyway.class.getName());
+    }
+
+    public void detectDataSourceDefinition(@Observes @WithAnnotations(DataSourceDefinition.class) ProcessAnnotatedType<?> patEvent) {
+        AnnotatedType at = patEvent.getAnnotatedType();
+        dataSourceDefinition = at.getAnnotation(DataSourceDefinition.class);
+    }
+
+    public void processAnnotatedType(@Observes ProcessAnnotatedType<Flyway> patEvent) {
+        patEvent.configureAnnotatedType()
+                //Add Scope
+                .add(ApplicationScoped.Literal.INSTANCE)
+                //Add Qualifier
+                .add(new AnnotationLiteral<FlywayType>() {
+                })
+                //Decorate setDataSource(DataSource dataSource){} with @Inject
+                .filterMethods(annotatedMethod -> {
+                    return annotatedMethod.getParameters().size() == 1 &&
+                            annotatedMethod.getParameters().get(0).getBaseType().equals(javax.sql.DataSource.class);
+                })
+                .findFirst().get().add(InjectLiteral.INSTANCE);
+    }
+
+    void afterBeanDiscovery(@Observes AfterBeanDiscovery abdEvent, BeanManager bm) {
+        abdEvent.addBean()
+                .types(javax.sql.DataSource.class, DataSource.class)
+                .qualifiers(new AnnotationLiteral<Default>() {}, new AnnotationLiteral<Any>() {})
+                .scope(ApplicationScoped.class)
+                .name(DataSource.class.getName())
+                .beanClass(DataSource.class)
+                .createWith(creationalContext -> {
+                    DataSource instance = new DataSource();
+                    instance.setUrl(dataSourceDefinition.url());
+                    instance.setDriverClassName(dataSourceDefinition.className());
+                    return instance;
+                });
+    }
+
+    void runFlywayMigration(@Observes AfterDeploymentValidation adv, BeanManager manager) {
+        Flyway flyway = manager.createInstance().select(Flyway.class, new AnnotationLiteral<FlywayType>() {}).get();
+        flyway.migrate();
+    }
+}

flyway-cdi-extension/src/main/java/com/baeldung/cdi/extension/FlywayType.java

@@ -0,0 +1,14 @@
+package com.baeldung.cdi.extension;
+
+import javax.inject.Qualifier;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+import static java.lang.annotation.ElementType.*;
+
+@Retention(RetentionPolicy.RUNTIME)
+@Target({FIELD, METHOD, PARAMETER, TYPE})
+@Qualifier
+public @interface FlywayType {
+}

flyway-cdi-extension/src/main/java/com/baeldung/cdi/extension/MainApp.java

@@ -0,0 +1,16 @@
+package com.baeldung.cdi.extension;
+
+import javax.annotation.sql.DataSourceDefinition;
+import javax.enterprise.context.ApplicationScoped;
+import javax.enterprise.inject.se.SeContainer;
+import javax.enterprise.inject.se.SeContainerInitializer;
+
+@ApplicationScoped
+@DataSourceDefinition(name = "ds", className = "org.h2.Driver", url = "jdbc:h2:mem:testdb")
+public class MainApp {
+    public static void main(String[] args) {
+        SeContainerInitializer initializer = SeContainerInitializer.newInstance();
+        try (SeContainer container = initializer.initialize()) {
+        }
+    }
+}

flyway-cdi-extension/src/main/resources/META-INF/beans.xml

@@ -0,0 +1,6 @@
+<beans version="2.0" xmlns="http://xmlns.jcp.org/xml/ns/javaee"
+       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+       xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee
+		http://xmlns.jcp.org/xml/ns/javaee/beans_2_0.xsd"
+       bean-discovery-mode="annotated">
+</beans>

flyway-cdi-extension/src/main/resources/META-INF/services/javax.enterprise.inject.spi.Extension

@@ -0,0 +1,2 @@
+com.baeldung.cdi.extension.FlywayExtension
+

flyway-cdi-extension/src/main/resources/db/migration/V1__Create_person_table.sql

@@ -0,0 +1,4 @@
+create table PERSON (
+    ID int not null,
+    NAME varchar(100) not null
+);

flyway-cdi-extension/src/main/resources/db/migration/V2__Add_people.sql

@@ -0,0 +1,3 @@
+insert into PERSON (ID, NAME) values (1, 'Axel');
+insert into PERSON (ID, NAME) values (2, 'Mr. Foo');
+insert into PERSON (ID, NAME) values (3, 'Ms. Bar');

gson/src/main/java/org/baeldung/gson/entities/Employee.java

@@ -0,0 +1,36 @@
+package org.baeldung.gson.entities;
+
+public class Employee {
+    private int id;
+    private String name;
+    private String address;
+
+    public Employee(int id, String name) {
+        this.id = id;
+        this.name = name;
+    }
+
+    public int getId() {
+        return id;
+    }
+
+    public void setId(int id) {
+        this.id = id;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    public String getAddress() {
+        return address;
+    }
+
+    public void setAddress(String address) {
+        this.address = address;
+    }
+}

gson/src/main/java/org/baeldung/gson/serialization/HashMapDeserializer.java

@@ -0,0 +1,66 @@
+package org.baeldung.gson.serialization;
+
+import java.lang.reflect.Type;
+import java.math.BigDecimal;
+import java.util.HashMap;
+import java.util.Map;
+
+import org.baeldung.gson.entities.Employee;
+
+import com.google.gson.*;
+
+public class HashMapDeserializer implements JsonDeserializer<HashMap<String, Object>> {
+
+    @Override
+    public HashMap<String, Object> deserialize(JsonElement elem, Type type, JsonDeserializationContext context) throws JsonParseException {
+        HashMap<String, Object> map = new HashMap<>();
+        for (Map.Entry<String, JsonElement> entry : elem.getAsJsonObject().entrySet()) {
+            JsonElement jsonValue = entry.getValue();
+            Object value = null;
+            if (jsonValue.isJsonPrimitive()) {
+                value = toPrimitive(jsonValue.getAsJsonPrimitive(), context);
+            } else {
+                value = context.deserialize(jsonValue, Employee.class);
+            }
+            map.put(entry.getKey(), value);
+        }
+        return map;
+
+    }
+
+    private Object toPrimitive(JsonPrimitive jsonValue, JsonDeserializationContext context) {
+        if (jsonValue.isBoolean())
+            return jsonValue.getAsBoolean();
+        else if (jsonValue.isString())
+            return jsonValue.getAsString();
+        else {
+            BigDecimal bigDec = jsonValue.getAsBigDecimal();
+            Long l;
+            Integer i;
+            if ((i = toInteger(bigDec)) != null) {
+                return i;
+            } else if ((l = toLong(bigDec)) != null) {
+                return l;
+            } else {
+                return bigDec.doubleValue();
+            }
+        }
+    }
+
+    private Long toLong(BigDecimal val) {
+        try {
+            return val.toBigIntegerExact().longValue();
+        } catch (ArithmeticException e) {
+            return null;
+        }
+    }
+
+    private Integer toInteger(BigDecimal val) {
+        try {
+            return val.intValueExact();
+        } catch (ArithmeticException e) {
+            return null;
+        }
+    }
+
+}

gson/src/main/resources/logback.xml

@@ -7,13 +7,13 @@
         </encoder>
     </appender>
 
-    <logger name="org.springframework" level="WARN" />
+    <logger name="org.springframework" level="WARN"/>
-    <logger name="org.springframework.transaction" level="WARN" />
+    <logger name="org.springframework.transaction" level="WARN"/>
 
     <!-- in order to debug some marshalling issues, this needs to be TRACE -->
-    <logger name="org.springframework.web.servlet.mvc" level="WARN" />
+    <logger name="org.springframework.web.servlet.mvc" level="WARN"/>
 
     <root level="INFO">
-        <appender-ref ref="STDOUT" />
+        <appender-ref ref="STDOUT"/>
     </root>
 </configuration>

gson/src/test/java/org/baeldung/gson/deserialization/HashMapDeserializationUnitTest.java

@@ -0,0 +1,86 @@
+package org.baeldung.gson.deserialization;
+
+import java.lang.reflect.Type;
+import java.util.HashMap;
+
+import org.baeldung.gson.entities.Employee;
+import org.baeldung.gson.serialization.HashMapDeserializer;
+import org.junit.Assert;
+import org.junit.Test;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import com.google.gson.Gson;
+import com.google.gson.GsonBuilder;
+import com.google.gson.JsonSyntaxException;
+import com.google.gson.internal.LinkedTreeMap;
+import com.google.gson.reflect.TypeToken;
+
+public class HashMapDeserializationUnitTest {
+
+    private static final Logger logger = LoggerFactory.getLogger(HashMapDeserializationUnitTest.class);
+
+    @Test
+    public void whenUsingHashMapClass_thenShouldReturnMapWithDefaultClasses() {
+
+        String jsonString = "{'employee.name':'Bob','employee.salary':10000, 'employee.active':true, "
+          + "'employee':{'id':10, 'name': 'Bob Willis', 'address':'London'}}";
+
+        Gson gson = new Gson();
+        HashMap map = gson.fromJson(jsonString, HashMap.class);
+
+        logger.info("The converted map: {}", map);
+        Assert.assertEquals(4, map.size());
+        Assert.assertEquals(Double.class, map.get("employee.salary").getClass());
+        Assert.assertEquals(LinkedTreeMap.class, map.get("employee").getClass());
+
+    }
+
+    @Test(expected = JsonSyntaxException.class)
+    public void whenUsingJsonStringWithDuplicateKey_thenShouldThrowJsonSyntaxException() {
+
+        String jsonString = "{'employee.name':'Bob', 'employee.name':'Jenny','employee.salary':10000, "
+          + "'employee.active':true, " + "'employee':{'id':10, 'name': 'Bob Willis', 'address':'London'}}";
+
+        Gson gson = new Gson();
+        HashMap map = gson.fromJson(jsonString, HashMap.class);
+
+        logger.info("The converted map: {}", map);
+    }
+
+    @Test
+    public void whenUsingTypeToken_thenShouldReturnMapWithProperClass() {
+
+        String jsonString = "{'Bob':{'id':10, 'name': 'Bob Willis', 'address':'UK'},"
+          + "'Jenny':{'id':10, 'name': 'Jenny McCarthy', 'address':'USA'}, "
+          + "'Steve':{'id':10, 'name': 'Steven Waugh', 'address':'Australia'}}";
+
+        Gson gson = new Gson();
+        Type empMapType = new TypeToken<HashMap<String, Employee>>(){}.getType();
+        HashMap<String, Employee> nameEmployeeMap = gson.fromJson(jsonString, empMapType);
+
+        logger.info("The converted map: {}", nameEmployeeMap);
+        Assert.assertEquals(3, nameEmployeeMap.size());
+        Assert.assertEquals(Employee.class, nameEmployeeMap.get("Bob").getClass());
+    }
+
+    @Test
+    public void whenUsingCustomDeserializer_thenShouldReturnMapWithProperClass() {
+
+        String jsonString = "{'employee.name':'Bob','employee.salary':10000, 'employee.active':true, "
+          + "'employee':{'id':10, 'name': 'Bob Willis', 'address':'London'}}";
+
+        Type type = new TypeToken<HashMap<String, Object>>(){}.getType();
+        Gson gson = new GsonBuilder()
+          .registerTypeAdapter(type, new HashMapDeserializer())
+          .create();
+        HashMap<String, Object> blendedMap = gson.fromJson(jsonString, type);
+
+        logger.info("The converted map: {}", blendedMap);
+        Assert.assertEquals(4, blendedMap.size());
+        Assert.assertEquals(Integer.class, blendedMap.get("employee.salary").getClass());
+        Assert.assertEquals(Employee.class, blendedMap.get("employee").getClass());
+
+    }
+
+}

gson/src/test/resources/logback-test.xml

@@ -0,0 +1,19 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<configuration>
+    <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
+        <encoder>
+            <pattern>%d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n
+            </pattern>
+        </encoder>
+    </appender>
+
+    <logger name="org.springframework" level="WARN"/>
+    <logger name="org.springframework.transaction" level="WARN"/>
+
+    <!-- in order to debug some marshalling issues, this needs to be TRACE -->
+    <logger name="org.springframework.web.servlet.mvc" level="WARN"/>
+
+    <root level="INFO">
+        <appender-ref ref="STDOUT"/>
+    </root>
+</configuration>

hibernate5/src/main/java/com/baeldung/hibernate/namingstrategy/CustomPhysicalNamingStrategy.java

@@ -0,0 +1,47 @@
+package com.baeldung.hibernate.namingstrategy;
+
+import org.hibernate.boot.model.naming.Identifier;
+import org.hibernate.boot.model.naming.PhysicalNamingStrategy;
+import org.hibernate.engine.jdbc.env.spi.JdbcEnvironment;
+
+public class CustomPhysicalNamingStrategy implements PhysicalNamingStrategy {
+
+    @Override
+    public Identifier toPhysicalCatalogName(final Identifier identifier, final JdbcEnvironment jdbcEnv) {
+        return convertToSnakeCase(identifier);
+    }
+
+    @Override
+    public Identifier toPhysicalColumnName(final Identifier identifier, final JdbcEnvironment jdbcEnv) {
+        return convertToSnakeCase(identifier);
+    }
+
+    @Override
+    public Identifier toPhysicalSchemaName(final Identifier identifier, final JdbcEnvironment jdbcEnv) {
+        return convertToSnakeCase(identifier);
+    }
+
+    @Override
+    public Identifier toPhysicalSequenceName(final Identifier identifier, final JdbcEnvironment jdbcEnv) {
+        return convertToSnakeCase(identifier);
+    }
+
+    @Override
+    public Identifier toPhysicalTableName(final Identifier identifier, final JdbcEnvironment jdbcEnv) {
+        return convertToSnakeCase(identifier);
+    }
+
+    private Identifier convertToSnakeCase(final Identifier identifier) {
+        if (identifier == null) {
+            return identifier;
+        }
+
+        final String regex = "([a-z])([A-Z])";
+        final String replacement = "$1_$2";
+        final String newName = identifier.getText()
+            .replaceAll(regex, replacement)
+            .toLowerCase();
+        return Identifier.toIdentifier(newName);
+    }
+
+}

hibernate5/src/main/java/com/baeldung/hibernate/namingstrategy/Customer.java

@@ -0,0 +1,56 @@
+package com.baeldung.hibernate.namingstrategy;
+
+import javax.persistence.Column;
+import javax.persistence.Entity;
+import javax.persistence.GeneratedValue;
+import javax.persistence.Id;
+import javax.persistence.Table;
+
+@Entity
+@Table(name = "Customers")
+public class Customer {
+
+    @Id
+    @GeneratedValue
+    private Long id;
+
+    private String firstName;
+
+    private String lastName;
+
+    @Column(name = "email")
+    private String emailAddress;
+
+    public Long getId() {
+        return id;
+    }
+
+    public void setId(Long id) {
+        this.id = id;
+    }
+
+    public String getFirstName() {
+        return firstName;
+    }
+
+    public void setFirstName(String firstName) {
+        this.firstName = firstName;
+    }
+
+    public String getLastName() {
+        return lastName;
+    }
+
+    public void setLastName(String lastName) {
+        this.lastName = lastName;
+    }
+
+    public String getEmailAddress() {
+        return emailAddress;
+    }
+
+    public void setEmailAddress(String emailAddress) {
+        this.emailAddress = emailAddress;
+    }
+
+}

hibernate5/src/main/java/com/baeldung/hibernate/proxy/BatchEmployee.java

@@ -1,56 +0,0 @@
-package com.baeldung.hibernate.proxy;
-
-import org.hibernate.annotations.BatchSize;
-
-import javax.persistence.*;
-import java.io.Serializable;
-
-@Entity
-@BatchSize(size = 5)
-public class BatchEmployee implements Serializable {
-
-    @Id
-    @GeneratedValue (strategy = GenerationType.SEQUENCE)
-    private Long id;
-
-    @ManyToOne(fetch = FetchType.LAZY)
-    private Boss boss;
-
-    @Column(name = "name")
-    private String name;
-
-    @Column(name = "surname")
-    private String surname;
-
-    public Long getId() {
-        return id;
-    }
-
-    public void setId(Long id) {
-        this.id = id;
-    }
-
-    public Boss getBoss() {
-        return boss;
-    }
-
-    public void setBoss(Boss boss) {
-        this.boss = boss;
-    }
-
-    public String getName() {
-        return name;
-    }
-
-    public void setName(String name) {
-        this.name = name;
-    }
-
-    public String getSurname() {
-        return surname;
-    }
-
-    public void setSurname(String surname) {
-        this.surname = surname;
-    }
-}

hibernate5/src/main/java/com/baeldung/hibernate/proxy/Boss.java

@@ -1,49 +0,0 @@
-package com.baeldung.hibernate.proxy;
-
-import javax.persistence.*;
-import java.io.Serializable;
-
-@Entity
-public class Boss implements Serializable {
-
-    @Id
-    @GeneratedValue(strategy = GenerationType.SEQUENCE)
-    private Long id;
-
-    @Column(name = "name")
-    private String name;
-
-    @Column(name = "surname")
-    private String surname;
-
-    public Boss() { }
-
-    public Boss(String name, String surname) {
-        this.name = name;
-        this.surname = surname;
-    }
-
-    public Long getId() {
-        return id;
-    }
-
-    public void setId(Long id) {
-        this.id = id;
-    }
-
-    public String getName() {
-        return name;
-    }
-
-    public void setName(String name) {
-        this.name = name;
-    }
-
-    public String getSurname() {
-        return surname;
-    }
-
-    public void setSurname(String surname) {
-        this.surname = surname;
-    }
-}

hibernate5/src/main/java/com/baeldung/hibernate/proxy/Company.java

@@ -0,0 +1,62 @@
+package com.baeldung.hibernate.proxy;
+
+import javax.persistence.*;
+import java.io.Serializable;
+import java.util.HashSet;
+import java.util.Objects;
+import java.util.Set;
+
+@Entity
+public class Company implements Serializable {
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.SEQUENCE)
+    private Long id;
+
+    @Column(name = "name")
+    private String name;
+
+    @OneToMany
+    @JoinColumn(name = "workplace_id")
+    private Set<Employee> employees = new HashSet<>();
+
+    public Company() { }
+
+    public Company(String name) {
+        this.name = name;
+    }
+
+    public Long getId() {
+        return id;
+    }
+
+    public void setId(Long id) {
+        this.id = id;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    public Set<Employee> getEmployees() {
+        return this.employees;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        Company company = (Company) o;
+        return Objects.equals(id, company.id) &&
+                Objects.equals(name, company.name);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(id, name);
+    }
+}

hibernate5/src/main/java/com/baeldung/hibernate/proxy/Employee.java

@@ -1,9 +1,13 @@
 package com.baeldung.hibernate.proxy;
 
+import org.hibernate.annotations.BatchSize;
+
 import javax.persistence.*;
 import java.io.Serializable;
+import java.util.Objects;
 
 @Entity
+@BatchSize(size = 5)
 public class Employee implements Serializable {
 
     @Id
@@ -11,13 +15,18 @@ public class Employee implements Serializable {
     private Long id;
 
     @ManyToOne(fetch = FetchType.LAZY)
-    private Boss boss;
+    @JoinColumn(name = "workplace_id")
+    private Company workplace;
 
-    @Column(name = "name")
+    @Column(name = "first_name")
-    private String name;
+    private String firstName;
 
-    @Column(name = "surname")
+    public Employee() { }
-    private String surname;
+
+    public Employee(Company workplace, String firstName) {
+        this.workplace = workplace;
+        this.firstName = firstName;
+    }
 
     public Long getId() {
         return id;
@@ -27,27 +36,34 @@ public class Employee implements Serializable {
         this.id = id;
     }
 
-    public Boss getBoss() {
+    public Company getWorkplace() {
-        return boss;
+        return workplace;
     }
 
-    public void setBoss(Boss boss) {
+    public void setWorkplace(Company workplace) {
-        this.boss = boss;
+        this.workplace = workplace;
     }
 
-    public String getName() {
+    public String getFirstName() {
-        return name;
+        return firstName;
     }
 
-    public void setName(String name) {
+    public void setFirstName(String firstName) {
-        this.name = name;
+        this.firstName = firstName;
     }
 
-    public String getSurname() {
+    @Override
-        return surname;
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        Employee employee = (Employee) o;
+        return Objects.equals(id, employee.id) &&
+                Objects.equals(workplace, employee.workplace) &&
+                Objects.equals(firstName, employee.firstName);
     }
 
-    public void setSurname(String surname) {
+    @Override
-        this.surname = surname;
+    public int hashCode() {
+        return Objects.hash(id, workplace, firstName);
     }
 }

hibernate5/src/main/java/com/baeldung/hibernate/proxy/HibernateUtil.java

@@ -30,7 +30,7 @@ public class HibernateUtil {
     private static SessionFactoryBuilder getSessionFactoryBuilder(ServiceRegistry serviceRegistry) {
         MetadataSources metadataSources = new MetadataSources(serviceRegistry);
         metadataSources.addPackage("com.baeldung.hibernate.proxy");
-        metadataSources.addAnnotatedClass(Boss.class);
+        metadataSources.addAnnotatedClass(Company.class);
         metadataSources.addAnnotatedClass(Employee.class);
 
         Metadata metadata = metadataSources.buildMetadata();

hibernate5/src/test/java/com/baeldung/hibernate/namingstrategy/NamingStrategyLiveTest.java

@@ -0,0 +1,75 @@
+package com.baeldung.hibernate.namingstrategy;
+
+import static org.junit.Assert.fail;
+
+import java.io.IOException;
+import java.util.Properties;
+
+import org.hibernate.HibernateException;
+import org.hibernate.Session;
+import org.hibernate.SessionFactory;
+import org.hibernate.boot.MetadataSources;
+import org.hibernate.boot.registry.StandardServiceRegistryBuilder;
+import org.hibernate.cfg.Configuration;
+import org.hibernate.service.ServiceRegistry;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+
+public class NamingStrategyLiveTest {
+
+    private Session session;
+
+    @Before
+    public void init() {
+        try {
+            Configuration configuration = new Configuration();
+
+            Properties properties = new Properties();
+            properties.load(Thread.currentThread()
+                .getContextClassLoader()
+                .getResourceAsStream("hibernate-namingstrategy.properties"));
+
+            configuration.setProperties(properties);
+
+            ServiceRegistry serviceRegistry = new StandardServiceRegistryBuilder().applySettings(configuration.getProperties())
+                .build();
+            MetadataSources metadataSources = new MetadataSources(serviceRegistry);
+            metadataSources.addAnnotatedClass(Customer.class);
+
+            SessionFactory factory = metadataSources.buildMetadata()
+                .buildSessionFactory();
+
+            session = factory.openSession();
+        } catch (HibernateException | IOException e) {
+            fail("Failed to initiate Hibernate Session [Exception:" + e.toString() + "]");
+        }
+    }
+
+    @After
+    public void close() {
+        if (session != null)
+            session.close();
+    }
+
+    @Test
+    public void testCustomPhysicalNamingStrategy() {
+
+        Customer customer = new Customer();
+        customer.setFirstName("first name");
+        customer.setLastName("last name");
+        customer.setEmailAddress("customer@example.com");
+
+        session.beginTransaction();
+
+        Long id = (Long) session.save(customer);
+
+        session.flush();
+        session.clear();
+
+        Object[] result = (Object[]) session.createNativeQuery("select c.first_name, c.last_name, c.email from customers c where c.id = :id")
+            .setParameter("id", id)
+            .getSingleResult();
+
+    }
+}

hibernate5/src/test/java/com/baeldung/hibernate/proxy/HibernateProxyUnitTest.java

@@ -1,6 +1,7 @@
 package com.baeldung.hibernate.proxy;
 
 import org.hibernate.*;
+import org.hibernate.proxy.HibernateProxy;
 import org.junit.After;
 import org.junit.Before;
 import org.junit.Test;
@@ -8,25 +9,31 @@ import org.junit.Test;
 import static org.junit.Assert.*;
 
 import java.io.IOException;
-import java.util.List;
 
 import static org.junit.Assert.fail;
 
 public class HibernateProxyUnitTest {
 
+    private SessionFactory factory;
+
     private Session session;
 
+    private Company workplace;
+
+    private Employee albert;
+
+    private Employee bob;
+
+    private Employee charlotte;
+
     @Before
     public void init(){
         try {
-            session = HibernateUtil.getSessionFactory("hibernate.properties")
+            factory = HibernateUtil.getSessionFactory("hibernate.properties");
-                    .openSession();
+            session = factory.openSession();
         } catch (HibernateException | IOException e) {
             fail("Failed to initiate Hibernate Session [Exception:" + e.toString() + "]");
         }
-
-        Boss boss = new Boss("Eduard", "Freud");
-        session.save(boss);
     }
 
     @After
@@ -36,40 +43,114 @@ public class HibernateProxyUnitTest {
         }
     }
 
-    @Test(expected = NullPointerException.class)
+    @Test
     public void givenAnInexistentEmployeeId_whenUseGetMethod_thenReturnNull() {
-        Employee employee = session.get(Employee.class, new Long(14));
+        Employee employee = session.get(Employee.class, 14L);
         assertNull(employee);
-        employee.getId();
     }
 
-    @Test
+    @Test(expected = ObjectNotFoundException.class)
-    public void givenAnInexistentEmployeeId_whenUseLoadMethod_thenReturnAProxy() {
+    public void givenAnNonExistentEmployeeId_whenUseLoadMethod_thenThrowObjectNotFoundException() {
-        Employee employee = session.load(Employee.class, new Long(14));
+        Employee employee = session.load(Employee.class, 999L);
         assertNotNull(employee);
+        employee.getFirstName();
     }
 
     @Test
-    public void givenABatchEmployeeList_whenSaveOne_thenSaveTheWholeBatch() {
+    public void givenAnNonExistentEmployeeId_whenUseLoadMethod_thenReturnAProxy() {
-        Transaction transaction = session.beginTransaction();
+        Employee employee = session.load(Employee.class, 14L);
-
+        assertNotNull(employee);
-        for (long i = 1; i <= 5; i++) {
+        assertTrue(employee instanceof HibernateProxy);
-            Employee employee = new Employee();
-            employee.setName("Employee " + i);
-            session.save(employee);
     }
 
-        //After this line is possible to see all the insertions in the logs
+    @Test
+    public void givenAnEmployeeFromACompany_whenUseLoadMethod_thenCompanyIsAProxy() {
+        Transaction tx = session.beginTransaction();
+
+        this.workplace = new Company("Bizco");
+        session.save(workplace);
+
+        this.albert = new Employee(workplace, "Albert");
+        session.save(albert);
+
         session.flush();
         session.clear();
-        transaction.commit();
 
-        transaction = session.beginTransaction();
+        tx.commit();
+        this.session = factory.openSession();
 
-        List<Employee> employeeList = session.createQuery("from Employee")
+        Employee proxyAlbert = session.load(Employee.class, albert.getId());
-                                        .setCacheMode(CacheMode.IGNORE).getResultList();
+        assertTrue(proxyAlbert instanceof HibernateProxy);
 
-        assertEquals(employeeList.size(), 5);
+        // with many-to-one lazy-loading, associations remain proxies
-        transaction.commit();
+        assertTrue(proxyAlbert.getWorkplace() instanceof HibernateProxy);
+    }
+
+    @Test
+    public void givenACompanyWithEmployees_whenUseLoadMethod_thenEmployeesAreProxies() {
+        Transaction tx = session.beginTransaction();
+
+        this.workplace = new Company("Bizco");
+        session.save(workplace);
+
+        this.albert = new Employee(workplace, "Albert");
+        session.save(albert);
+
+        session.flush();
+        session.clear();
+
+        tx.commit();
+        this.session = factory.openSession();
+
+        Company proxyBizco = session.load(Company.class, workplace.getId());
+        assertTrue(proxyBizco instanceof HibernateProxy);
+
+        // with one-to-many, associations aren't proxies
+        assertFalse(proxyBizco.getEmployees().iterator().next() instanceof HibernateProxy);
+    }
+
+    @Test
+    public void givenThreeEmployees_whenLoadThemWithBatch_thenReturnAllOfThemWithOneQuery() {
+        Transaction tx = session.beginTransaction();
+
+        //We are saving 3 entities with one flush
+
+        this.workplace = new Company("Bizco");
+        session.save(workplace);
+
+        this.albert = new Employee(workplace, "Albert");
+        session.save(albert);
+
+        this.bob = new Employee(workplace, "Bob");
+        session.save(bob);
+
+        this.charlotte = new Employee(workplace, "Charlotte");
+        session.save(charlotte);
+
+        session.flush();
+        session.clear();
+
+        tx.commit();
+        session = factory.openSession();
+
+        Employee proxyAlbert = session.load(Employee.class, this.albert.getId());
+        assertNotNull(proxyAlbert);
+        assertTrue(proxyAlbert instanceof HibernateProxy);
+
+        Employee proxyBob = session.load(Employee.class, this.bob.getId());
+        assertNotNull(proxyBob);
+        assertTrue(proxyBob instanceof HibernateProxy);
+
+        Employee proxyCharlotte = session.load(Employee.class, this.charlotte.getId());
+        assertNotNull(proxyCharlotte);
+        assertTrue(proxyCharlotte instanceof HibernateProxy);
+
+        //Fetching from database 3 entities with one call
+        //Select from log: where employee0_.id in (?, ?, ?)
+        proxyAlbert.getFirstName();
+
+        assertEquals(proxyAlbert, this.albert);
+        assertEquals(proxyBob, this.bob);
+        assertEquals(proxyCharlotte, this.charlotte);
     }
 }

hibernate5/src/test/resources/hibernate-namingstrategy.properties

@@ -0,0 +1,10 @@
+hibernate.connection.driver_class=org.h2.Driver
+hibernate.connection.url=jdbc:h2:mem:mydb1;DB_CLOSE_DELAY=-1
+hibernate.connection.username=sa
+hibernate.dialect=org.hibernate.dialect.H2Dialect
+
+hibernate.show_sql=true
+hibernate.hbm2ddl.auto=create-drop
+
+hibernate.physical_naming_strategy=com.baeldung.hibernate.namingstrategy.CustomPhysicalNamingStrategy
+hibernate.implicit_naming_strategy=org.hibernate.boot.model.naming.ImplicitNamingStrategyJpaCompliantImpl

java-numbers/src/test/java/com/baeldung/maths/MathSinUnitTest.java

@@ -0,0 +1,20 @@
+package com.baeldung.maths;
+
+import static org.junit.Assert.assertTrue;
+
+import org.junit.jupiter.api.Test;
+
+public class MathSinUnitTest {
+
+    @Test
+    public void givenAnAngleInDegrees_whenUsingToRadians_thenResultIsInRadians() {
+        double angleInDegrees = 30;
+        double sinForDegrees = Math.sin(Math.toRadians(angleInDegrees)); // 0.5
+
+        double thirtyDegreesInRadians = 1/6 * Math.PI;
+        double sinForRadians = Math.sin(thirtyDegreesInRadians); // 0.5
+
+        assertTrue(sinForDegrees == sinForRadians);
+    }
+
+}

jee-7/README.md

@@ -6,3 +6,4 @@
 - [A Guide to Java EE Web-Related Annotations](http://www.baeldung.com/javaee-web-annotations)
 - [Introduction to Testing with Arquillian](http://www.baeldung.com/arquillian)
 - [Securing Java EE with Spring Security](http://www.baeldung.com/java-ee-spring-security)
+- [A Guide to Java EE Web-Related Annotations](https://www.baeldung.com/javaee-web-annotations)

jee-7/pom.xml

@@ -130,7 +130,7 @@
                 <artifactId>maven-war-plugin</artifactId>
                 <version>${maven-war-plugin.version}</version>
                 <configuration>
-                    <warSourceDirectory>webapp</warSourceDirectory>
+                    <warSourceDirectory>src/main/webapp</warSourceDirectory>
                     <failOnMissingWebXml>false</failOnMissingWebXml>
                 </configuration>
             </plugin>

jee-7/src/main/java/com/baeldung/javaeeannotations/AccountServlet.java

@@ -1,4 +1,4 @@
-package com.baeldung.javaeeannotations.JavaEEAnnotationsSample.src.main.java.com.baeldung.javaeeannotations;
+package com.baeldung.javaeeannotations;
 
 import java.io.IOException;
 import java.io.PrintWriter;

jee-7/src/main/java/com/baeldung/javaeeannotations/BankAppServletContextListener.java

@@ -1,4 +1,4 @@
-package com.baeldung.javaeeannotations.JavaEEAnnotationsSample.src.main.java.com.baeldung.javaeeannotations;
+package com.baeldung.javaeeannotations;
 
 import javax.servlet.ServletContextEvent;
 import javax.servlet.ServletContextListener;

jee-7/src/main/java/com/baeldung/javaeeannotations/JavaEEAnnotationsSample/README.txt

@@ -1,76 +0,0 @@
-About the application
----------------------
-This application demonstrates the usage of JavaEE Web Annotations.
-
-
-Contents of the application
----------------------------
-1. AccountServlet.java - Demonstrates the @WebServlet and @ServletSecurity annotation.
-
-NOTES: @WebServlet annotation designates the AccountServlet class as a Servlet component.
-       The usage of its parameters 'urlPatterns' & 'initParams' can be observed.
-       An initialization parameter 'type' is being set to denote the type of the bank account.
-       
-       @ServletSecurity annotation imposes security constraints on the AccountServlet based on
-       the tomcat-users.xml.
-       
-       This code assumes that your tomcat-users.xml looks as follows:
-
-       <role rolename="Admin"/>
-       <role rolename="Member"/>
-       <role rolename="Guest"/>
-       <user username="Annie" password="admin" roles="Admin, Member, Guest" />
-       <user username="Diane" password="coder" roles="Member, Guest" />
-       <user username="Ted" password="newbie" roles="Guest" />
-   
-N.B : To see  @ServletSecurity annotation in action, please uncomment the annotation code 
-      for @ServletSecurity.
-      
-      
-2. BankAppServletContextListener.java - Demonstrates the @WebListener annotation for denoting a class as a ServletContextListener.
-   
-NOTES: Sets a Servlet context attribute ATTR_DEFAULT_LANGUAGE to 'english' on web application start up, 
-       which can then be used throughout the application.
-
-
-3. LogInFilter.java - Demonstrates the @WebFilter annotation.
-                      
-NOTES: @WebFilter annotation designates the LogInFilter class as a Filter component.
-       It filters all requests to the bank account servlet and redirects them to
-       the login page.
-       
-N.B : To see @WebFilter annotation in action, please uncomment the annotation code for @WebFilter.
-
-
-4. UploadCustomerDocumentsServlet.java - Demonstrates the @MultipartConfig annotation.
-
-NOTES: @MultipartConfig anotation designates the UploadCustomerDocumentsServlet Servlet component, 
-       to handle multipart/form-data requests.
-       To see it in action, deploy the web application an access the url: http://<your host>:<your port>/JavaEEAnnotationsSample/upload.jsp
-       Once you upload a file from here, it will get uploaded to D:/custDocs (assuming such a folder exists).
-       
- 
-5. index.jsp - This is the welcome page.
-
-NOTES: You can enter a deposit amount here and click on the 'Deposit' button to see the AccountServlet in action.
-
-6. login.jsp - All requests to the AccountServlet are redirected to this page, if the LogInFilter is imposed.
-
-7. upload.jsp - Demonstrates the usage of handling multipart/form-data requests by the UploadCustomerDocumentsServlet.       
-       
-   
-Building and Running the application
-------------------------------------
-To build the application:
-
-1. Open the project in eclipse
-2. Right click on it in eclispe and choose Run As > Maven build
-3. Give 'clean install' under Goals
-4. This should build the WAR file of the application
-
-To run the application:
-
-1. Right click on the project
-2. Run as > Run on Server
-3. This will start you Tomcat server and deploy the application (Provided that you have configured Tomcat in your eclipse)
-4. You should now be able to access the url : http://<your host>:<your port>/JavaEEAnnotationsSample

jee-7/src/main/java/com/baeldung/javaeeannotations/JavaEEAnnotationsSample/pom.xml

@@ -1,52 +0,0 @@
-<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
-    <modelVersion>4.0.0</modelVersion>
-    <groupId>com.baeldung.javaeeannotations</groupId>
-    <artifactId>JavaEEAnnotationsSample</artifactId>
-    <version>0.0.1-SNAPSHOT</version>
-    <packaging>war</packaging>
-    <name>JavaEEAnnotationsSample</name>
-    <description>JavaEEAnnotationsSample</description>
-    <parent>
-        <groupId>com.baeldung</groupId>
-        <artifactId>parent-modules</artifactId>
-        <version>1.0.0-SNAPSHOT</version>
-    </parent>
-    <dependencies>
-
-        <dependency>
-            <groupId>javax.annotation</groupId>
-            <artifactId>javax.annotation-api</artifactId>
-            <version>1.3</version>
-        </dependency>
-
-        <dependency>
-            <groupId>javax.servlet</groupId>
-            <artifactId>javax.servlet-api</artifactId>
-            <version>3.1.0</version>
-        </dependency>
-
-        <dependency>
-            <groupId>javax.servlet.jsp</groupId>
-            <artifactId>jsp-api</artifactId>
-            <version>2.1</version>
-        </dependency>
-
-    </dependencies>
-    <build>
-        <pluginManagement>
-            <plugins>
-                <plugin>
-                    <groupId>org.apache.maven.plugins</groupId>
-                    <artifactId>maven-war-plugin</artifactId>
-                    <version>2.4</version>
-                    <configuration>
-                        <warSourceDirectory>src/main/webapp</warSourceDirectory>
-                        <warName>SpringFieldConstructorInjection</warName>
-                        <failOnMissingWebXml>false</failOnMissingWebXml>
-                    </configuration>
-                </plugin>
-            </plugins>
-        </pluginManagement>
-        <finalName>JavaEEAnnotationsSample</finalName>
-    </build>
-</project>

jee-7/src/main/java/com/baeldung/javaeeannotations/JavaEEAnnotationsSample/src/main/webapp/WEB-INF/web.xml

@@ -1,10 +0,0 @@
-<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
-         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-         xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee
-                             http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd" version="3.1">
-
-    <login-config>
-        <auth-method>BASIC</auth-method>
-        <realm-name>default</realm-name>
-    </login-config>
-</web-app>

jee-7/src/main/java/com/baeldung/javaeeannotations/JavaEEAnnotationsSample/src/main/webapp/login.jsp

@@ -1,12 +0,0 @@
-<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
-    pageEncoding="ISO-8859-1"%>
-<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
-<html>
-<head>
-<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
-<title>Login</title>
-</head>
-<body>
-Login Here...
-</body>
-</html>

jee-7/src/main/java/com/baeldung/javaeeannotations/LogInFilter.java

@@ -1,4 +1,4 @@
-package com.baeldung.javaeeannotations.JavaEEAnnotationsSample.src.main.java.com.baeldung.javaeeannotations;
+package com.baeldung.javaeeannotations;
 
 import java.io.IOException;
 

jee-7/src/main/java/com/baeldung/javaeeannotations/UploadCustomerDocumentsServlet.java

@@ -1,4 +1,4 @@
-package com.baeldung.javaeeannotations.JavaEEAnnotationsSample.src.main.java.com.baeldung.javaeeannotations;
+package com.baeldung.javaeeannotations;
 
 import java.io.IOException;
 import java.io.PrintWriter;

maven-polyglot/README.md

@@ -0,0 +1,3 @@
+To run the maven-polyglot-json-app successfully, you first have to build the maven-polyglot-json-extension module using: mvn clean install.
+
+Related Articles:

maven-polyglot/maven-polyglot-json-app/.mvn/extensions.xml

@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<extensions>
+    <extension>
+        <groupId>com.baeldung.maven.polyglot</groupId>
+        <artifactId>maven-polyglot-json-extension</artifactId>
+        <version>1.0-SNAPSHOT</version>
+    </extension>
+</extensions>

maven-polyglot/maven-polyglot-json-app/pom.json

@@ -0,0 +1,34 @@
+{
+  "modelVersion": "4.0.0",
+  "groupId": "com.baeldung.maven.polyglot",
+  "artifactId": "maven-polyglot-json-app",
+  "version": "1.0-SNAPSHOT",
+  "name": "Json Maven Polyglot",
+  "parent": {
+    "groupId": "org.springframework.boot",
+    "artifactId": "spring-boot-starter-parent",
+    "version": "2.0.5.RELEASE",
+    "relativePath": null
+  },
+  "properties": {
+    "project.build.sourceEncoding": "UTF-8",
+    "project.reporting.outputEncoding": "UTF-8",
+    "maven.compiler.source": "1.8",
+    "maven.compiler.target": "1.8",
+    "java.version": "1.8"
+  },
+  "dependencies": [
+    {
+      "groupId": "org.springframework.boot",
+      "artifactId": "spring-boot-starter-web"
+    }
+  ],
+  "build": {
+    "plugins": [
+      {
+        "groupId": "org.springframework.boot",
+        "artifactId": "spring-boot-maven-plugin"
+      }
+    ]
+  }
+}

maven-polyglot/maven-polyglot-json-app/src/main/java/com/baeldung/maven/polyglot/MavenPolyglotApplication.java

@@ -0,0 +1,19 @@
+package com.baeldung.maven.polyglot;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.web.bind.annotation.RestController;
+import org.springframework.web.bind.annotation.GetMapping;
+
+@RestController
+@SpringBootApplication
+public class MavenPolyglotApplication {
+    public static void main(String[] args) {
+        SpringApplication.run(MavenPolyglotApplication.class, args);
+    }
+
+    @GetMapping("/")
+    public String home(){
+        return "Hello JSON Maven Model !";
+    }
+}

maven-polyglot/maven-polyglot-json-app/src/main/resources/model.json

@@ -0,0 +1,109 @@
+{
+  "modules": [],
+  "distributionManagement": null,
+  "properties": {
+    "project.reporting.outputEncoding": "UTF-8",
+    "java.version": "1.8",
+    "maven.compiler.source": "1.8",
+    "project.build.sourceEncoding": "UTF-8",
+    "maven.compiler.target": "1.8"
+  },
+  "dependencyManagement": null,
+  "dependencies": [
+    {
+      "groupId": "org.springframework.boot",
+      "artifactId": "spring-boot-starter-web",
+      "version": null,
+      "type": "jar",
+      "classifier": null,
+      "scope": null,
+      "systemPath": null,
+      "exclusions": [],
+      "optional": null,
+      "managementKey": "org.springframework.boot:spring-boot-starter-web:jar"
+    }
+  ],
+  "repositories": [],
+  "pluginRepositories": [],
+  "reports": null,
+  "reporting": null,
+  "modelVersion": "4.0.0",
+  "parent": {
+    "groupId": "org.springframework.boot",
+    "artifactId": "spring-boot-starter-parent",
+    "version": "2.0.5.RELEASE",
+    "relativePath": "",
+    "id": "org.springframework.boot:spring-boot-starter-parent:pom:2.0.5.RELEASE"
+  },
+  "groupId": "com.demo.polyglot",
+  "artifactId": "maven-polyglot-app",
+  "version": "1.0.1",
+  "packaging": "jar",
+  "name": "Json Maven Polyglot",
+  "description": null,
+  "url": null,
+  "inceptionYear": null,
+  "organization": null,
+  "licenses": [],
+  "developers": [],
+  "contributors": [],
+  "mailingLists": [],
+  "prerequisites": null,
+  "scm": null,
+  "issueManagement": null,
+  "ciManagement": null,
+  "build": {
+    "plugins": [
+      {
+        "inherited": null,
+        "configuration": null,
+        "inheritanceApplied": true,
+        "groupId": "org.liquibase",
+        "artifactId": "liquibase-maven-plugin",
+        "version": "3.0.5",
+        "extensions": null,
+        "executions": [],
+        "dependencies": [],
+        "goals": null,
+        "key": "org.liquibase:liquibase-maven-plugin",
+        "id": "org.liquibase:liquibase-maven-plugin:3.0.5",
+        "executionsAsMap": {}
+      }
+    ],
+    "pluginManagement": null,
+    "defaultGoal": null,
+    "resources": [],
+    "testResources": [],
+    "directory": null,
+    "finalName": null,
+    "filters": [],
+    "sourceDirectory": null,
+    "scriptSourceDirectory": null,
+    "testSourceDirectory": null,
+    "outputDirectory": null,
+    "testOutputDirectory": null,
+    "extensions": [],
+    "pluginsAsMap": {
+      "org.liquibase:liquibase-maven-plugin": {
+        "inherited": null,
+        "configuration": null,
+        "inheritanceApplied": true,
+        "groupId": "org.liquibase",
+        "artifactId": "liquibase-maven-plugin",
+        "version": "3.0.5",
+        "extensions": null,
+        "executions": [],
+        "dependencies": [],
+        "goals": null,
+        "key": "org.liquibase:liquibase-maven-plugin",
+        "id": "org.liquibase:liquibase-maven-plugin:3.0.5",
+        "executionsAsMap": {}
+      }
+    }
+  },
+  "profiles": [],
+  "modelEncoding": "UTF-8",
+  "pomFile": null,
+  "id": "com.demo.polyglot:maven-polyglot-app:jar:1.0.1",
+  "projectDirectory": null
+}

maven-polyglot/maven-polyglot-json-extension/pom.xml

@@ -0,0 +1,47 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+
+    <groupId>com.baeldung.maven.polyglot</groupId>
+    <artifactId>maven-polyglot-json-extension</artifactId>
+    <version>1.0-SNAPSHOT</version>
+
+    <properties>
+        <maven.compiler.source>1.8</maven.compiler.source>
+        <maven.compiler.target>1.8</maven.compiler.target>
+    </properties>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.apache.maven</groupId>
+            <artifactId>maven-core</artifactId>
+            <version>3.5.4</version>
+            <scope>provided</scope>
+        </dependency>
+        <dependency>
+            <groupId>com.fasterxml.jackson.core</groupId>
+            <artifactId>jackson-databind</artifactId>
+            <version>2.9.6</version>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.codehaus.plexus</groupId>
+                <artifactId>plexus-component-metadata</artifactId>
+                <version>1.7.1</version>
+                <executions>
+                    <execution>
+                        <goals>
+                            <goal>generate-metadata</goal>
+                        </goals>
+                    </execution>
+                </executions>
+            </plugin>
+        </plugins>
+    </build>
+
+</project>

maven-polyglot/maven-polyglot-json-extension/src/main/java/com/demo/polyglot/CustomModelProcessor.java

@@ -0,0 +1,62 @@
+package com.demo.polyglot;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+import org.apache.maven.model.Model;
+import org.apache.maven.model.building.FileModelSource;
+import org.apache.maven.model.building.ModelProcessor;
+import org.apache.maven.model.io.ModelParseException;
+import org.apache.maven.model.io.ModelReader;
+import org.codehaus.plexus.component.annotations.Component;
+import org.codehaus.plexus.component.annotations.Requirement;
+import org.codehaus.plexus.util.ReaderFactory;
+
+import java.io.File;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.Reader;
+import java.util.Map;
+
+@Component(role = ModelProcessor.class)
+public class CustomModelProcessor implements ModelProcessor {
+
+    private static final String XML_POM = "pom.xml";
+    private static final String JSON_POM = "pom.json";
+    private static final String JSON_EXT = ".json";
+
+    ObjectMapper objectMapper = new ObjectMapper();
+
+    @Requirement
+    private ModelReader modelReader;
+
+    @Override
+    public File locatePom(File projectDirectory) {
+        File pomFile = new File(projectDirectory, JSON_POM);
+        if (!pomFile.exists()) {
+            pomFile = new File(projectDirectory, XML_POM);
+        }
+        return pomFile;
+    }
+
+    @Override
+    public Model read(InputStream input, Map<String, ?> options) throws IOException, ModelParseException {
+        try (final Reader in = ReaderFactory.newPlatformReader(input)) {
+            return read(in, options);
+        }
+    }
+
+    @Override
+    public Model read(Reader reader, Map<String, ?> options) throws IOException, ModelParseException {
+        FileModelSource source = (options != null) ? (FileModelSource) options.get(SOURCE) : null;
+        if (source != null && source.getLocation().endsWith(JSON_EXT)) {
+            Model model = objectMapper.readValue(reader, Model.class);
+            return model;
+        }
+        //It's a normal maven project with a pom.xml file
+        return modelReader.read(reader, options);
+    }
+
+    @Override
+    public Model read(File input, Map<String, ?> options) throws IOException, ModelParseException {
+        return null;
+    }
+}

maven-polyglot/maven-polyglot-yml-app/.mvn/extensions.xml

@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<extensions>
+    <extension>
+        <groupId>io.takari.polyglot</groupId>
+        <artifactId>polyglot-yaml</artifactId>
+        <version>0.3.1</version>
+    </extension>
+</extensions>

maven-polyglot/maven-polyglot-yml-app/pom.yml

@@ -0,0 +1,7 @@
+modelVersion: 4.0.0
+groupId: com.baeldung.maven.polyglot
+artifactId: maven-polyglot-yml-app
+version: 1.0-SNAPSHOT
+name: 'YAML Demo'
+
+properties: {maven.compiler.source: 1.8, maven.compiler.target: 1.8}

maven-polyglot/maven-polyglot-yml-app/src/main/java/com/baeldung/maven/polyglot/YamlDemoApplication.java

@@ -0,0 +1,7 @@
+package com.baeldung.maven.polyglot;
+
+public class YamlDemoApplication {
+    public static void main(String[] args) {
+        System.out.println("Hello Maven Polyglot YAML !");
+    }
+}

maven-polyglot/maven-polyglot-yml-app/src/main/resources/model.json

@@ -0,0 +1,109 @@
+{
+  "modules": [],
+  "distributionManagement": null,
+  "properties": {
+    "project.reporting.outputEncoding": "UTF-8",
+    "java.version": "1.8",
+    "maven.compiler.source": "1.8",
+    "project.build.sourceEncoding": "UTF-8",
+    "maven.compiler.target": "1.8"
+  },
+  "dependencyManagement": null,
+  "dependencies": [
+    {
+      "groupId": "org.springframework.boot",
+      "artifactId": "spring-boot-starter-web",
+      "version": null,
+      "type": "jar",
+      "classifier": null,
+      "scope": null,
+      "systemPath": null,
+      "exclusions": [],
+      "optional": null,
+      "managementKey": "org.springframework.boot:spring-boot-starter-web:jar"
+    }
+  ],
+  "repositories": [],
+  "pluginRepositories": [],
+  "reports": null,
+  "reporting": null,
+  "modelVersion": "4.0.0",
+  "parent": {
+    "groupId": "org.springframework.boot",
+    "artifactId": "spring-boot-starter-parent",
+    "version": "2.0.5.RELEASE",
+    "relativePath": "",
+    "id": "org.springframework.boot:spring-boot-starter-parent:pom:2.0.5.RELEASE"
+  },
+  "groupId": "com.demo.polyglot",
+  "artifactId": "maven-polyglot-app",
+  "version": "1.0.1",
+  "packaging": "jar",
+  "name": "Json Maven Polyglot",
+  "description": null,
+  "url": null,
+  "inceptionYear": null,
+  "organization": null,
+  "licenses": [],
+  "developers": [],
+  "contributors": [],
+  "mailingLists": [],
+  "prerequisites": null,
+  "scm": null,
+  "issueManagement": null,
+  "ciManagement": null,
+  "build": {
+    "plugins": [
+      {
+        "inherited": null,
+        "configuration": null,
+        "inheritanceApplied": true,
+        "groupId": "org.liquibase",
+        "artifactId": "liquibase-maven-plugin",
+        "version": "3.0.5",
+        "extensions": null,
+        "executions": [],
+        "dependencies": [],
+        "goals": null,
+        "key": "org.liquibase:liquibase-maven-plugin",
+        "id": "org.liquibase:liquibase-maven-plugin:3.0.5",
+        "executionsAsMap": {}
+      }
+    ],
+    "pluginManagement": null,
+    "defaultGoal": null,
+    "resources": [],
+    "testResources": [],
+    "directory": null,
+    "finalName": null,
+    "filters": [],
+    "sourceDirectory": null,
+    "scriptSourceDirectory": null,
+    "testSourceDirectory": null,
+    "outputDirectory": null,
+    "testOutputDirectory": null,
+    "extensions": [],
+    "pluginsAsMap": {
+      "org.liquibase:liquibase-maven-plugin": {
+        "inherited": null,
+        "configuration": null,
+        "inheritanceApplied": true,
+        "groupId": "org.liquibase",
+        "artifactId": "liquibase-maven-plugin",
+        "version": "3.0.5",
+        "extensions": null,
+        "executions": [],
+        "dependencies": [],
+        "goals": null,
+        "key": "org.liquibase:liquibase-maven-plugin",
+        "id": "org.liquibase:liquibase-maven-plugin:3.0.5",
+        "executionsAsMap": {}
+      }
+    }
+  },
+  "profiles": [],
+  "modelEncoding": "UTF-8",
+  "pomFile": null,
+  "id": "com.demo.polyglot:maven-polyglot-app:jar:1.0.1",
+  "projectDirectory": null
+}

pom.xml

@@ -290,7 +290,7 @@
 	<profiles>
 
 		<profile>
-			<id>default</id>
+			<id>default-first</id>
 			<build>
 				<plugins>
 
@@ -332,6 +332,7 @@
 				<module>annotations</module>
 				<module>apache-cxf</module>
 				<module>apache-fop</module>
+				<module>apache-geode</module>
 				<module>apache-poi</module>
 				<module>apache-tika</module>
 				<module>apache-thrift</module>
@@ -522,9 +523,9 @@
 				<module>spring-rest-angular</module>
 				<module>spring-rest-full</module>
 				<module>spring-rest-query-language</module>
-				<module>spring-rest</module>
+				<!-- <module>spring-rest</module> --> <!-- temporarily disabled -->
+				<!-- <module>spring-rest-simple</module> --> <!-- temporarily disabled -->
 				<module>spring-resttemplate</module>
-				<module>spring-rest-simple</module>
 				<module>spring-security-acl</module>
 				<module>spring-security-cache-control</module>
 				<module>spring-security-client/spring-security-jsp-authentication</module>
@@ -550,6 +551,44 @@
 				<module>spring-security-rest</module>
 				<module>spring-security-sso</module>
 				<module>spring-security-x509</module>
+			</modules>
+
+		</profile>
+		
+        <profile>
+            <id>default-second</id>
+            <build>
+                <plugins>
+
+                    <plugin>
+                        <groupId>org.apache.maven.plugins</groupId>
+                        <artifactId>maven-surefire-plugin</artifactId>
+                        <version>${maven-surefire-plugin.version}</version>
+                        <configuration>
+                            <forkCount>3</forkCount>
+                            <reuseForks>true</reuseForks>
+                            <excludes>
+                                <exclude>**/*IntegrationTest.java</exclude>
+                                <exclude>**/*IntTest.java</exclude>
+                                <exclude>**/*LongRunningUnitTest.java</exclude>
+                                <exclude>**/*ManualTest.java</exclude>
+                                <exclude>**/JdbcTest.java</exclude>
+                                <exclude>**/*LiveTest.java</exclude>
+                            </excludes>
+                        </configuration>
+                    </plugin>
+
+                </plugins>
+            </build>
+
+            <modules>
+                <module>parent-boot-1</module>
+                <module>parent-boot-2</module>
+                <module>parent-spring-4</module>
+                <module>parent-spring-5</module>
+                <module>parent-java</module>
+                <module>parent-kotlin</module>
+                
                 <module>spring-session</module>
                 <module>spring-sleuth</module>
                 <module>spring-social-login</module>
@@ -671,7 +710,7 @@
                 <!-- <module>guest/spring-security</module> --><!-- guest post on different site -->
                 <!-- <module>guest/thread-pools</module> --><!-- guest post on different site -->
                 <!-- <module>guest/tomcat-app</module> --><!-- guest post on different site -->
-				<module>jenkins/hello-world</module>
+                <!-- <module>jenkins/hello-world</module> --> <!-- disabled in the default profile -->
                 <!-- <module>rule-engines/easy-rules</module> --><!-- Wrong Parent -->
                 <!-- <module>rule-engines/openl-tablets</module> --><!-- Wrong Parent -->
                 <!-- <module>rule-engines/rulebook</module> --><!-- Wrong Parent -->
@@ -681,6 +720,7 @@
                 <!-- <module>guest\webservices\rest-client</module> --><!-- guest post on different site -->
                 <!-- <module>guest\webservices\rest-server</module> --><!-- guest post on different site -->
                 <!-- <module>guest\webservices\spring-rest-service</module> --><!-- guest post on different site -->
+                <module>flyway-cdi-extension</module>                               
             </modules>
 
         </profile>
@@ -1447,7 +1487,6 @@
 				<module>spring-security-thymeleaf</module>
 				<module>persistence-modules/java-jdbi</module>
 				<module>jersey</module>
-				<module>jersey-client-rx</module>
 				<module>java-spi</module>
 				<module>performance-tests</module>
 				<module>twilio</module>

spring-boot/pom.xml

@@ -145,6 +145,20 @@
             <artifactId>chaos-monkey-spring-boot</artifactId>
             <version>${chaos.monkey.version}</version>
         </dependency>
+
+        <!-- for Graylog demo -->
+        <dependency>
+            <!-- forcing spring boot 1.x sing log4j was dropped in spring boot 1.4 and beyond -->
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-log4j</artifactId>
+            <version>1.3.8.RELEASE</version>
+        </dependency>
+        <dependency>
+            <groupId>org.graylog2</groupId>
+            <artifactId>gelfj</artifactId>
+            <version>1.1.16</version>
+            <scope>compile</scope>
+        </dependency>
     </dependencies>
 
     <build>

spring-boot/src/main/java/com/baeldung/graylog/GraylogDemoApplication.java

@@ -0,0 +1,17 @@
+package com.baeldung.graylog;
+
+import org.apache.log4j.Logger;
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class GraylogDemoApplication {
+
+    private final static Logger LOG =
+            Logger.getLogger(GraylogDemoApplication.class);
+
+    public static void main(String[] args) {
+        SpringApplication.run(GraylogDemoApplication.class, args);
+        LOG.info("Hello from Spring Boot");
+    }
+}

spring-boot/src/main/resources/log4j.xml

@@ -0,0 +1,24 @@
+<?xml version="1.0" encoding="UTF-8" ?>
+<!DOCTYPE log4j:configuration SYSTEM "http://logging.apache.org/log4j/1.2/apidocs/org/apache/log4j/xml/doc-files/log4j.dtd">
+<log4j:configuration>
+    <appender name="stdout" class="org.apache.log4j.ConsoleAppender">
+        <layout class="org.apache.log4j.PatternLayout">
+            <param name="ConversionPattern" value="%d{yyyy-MM-dd HH:mm:ss.SSS} %5p ${PID:- } [%t] --- %-40.40logger{39} : %m%n"/>
+        </layout>
+    </appender>
+    <appender name="graylog" class="org.graylog2.log.GelfAppender">
+        <param name="graylogHost" value="18.217.253.212"/>
+        <param name="originHost" value="localhost"/>
+        <param name="graylogPort" value="12201"/>
+        <param name="extractStacktrace" value="true"/>
+        <param name="addExtendedInformation" value="true"/>
+        <param name="facility" value="log4j"/>
+        <param name="Threshold" value="DEBUG"/>
+        <param name="additionalFields" value="{'environment': 'DEV', 'application': 'GraylogDemoApplication'}"/>
+    </appender>
+    <root>
+        <priority value="DEBUG"/>
+        <appender-ref ref="stdout"/>
+        <appender-ref ref="graylog"/>
+    </root>
+</log4j:configuration>