Merge branch 'master' into BAEL-4183-dependency-management-in-gradle

algorithms-miscellaneous-6/README.md

@@ -9,4 +9,5 @@
 - [The Caesar Cipher in Java](https://www.baeldung.com/java-caesar-cipher)
 - [Implementing a 2048 Solver in Java](https://www.baeldung.com/2048-java-solver)
 - [Finding Top K Elements in an Array](https://www.baeldung.com/java-array-top-elements)
+- [Reversing a Linked List in Java](https://www.baeldung.com/java-reverse-linked-list)
 - More articles: [[<-- prev]](/../algorithms-miscellaneous-5)

algorithms-miscellaneous-6/src/main/java/com/baeldung/algorithms/linkedlist/LinkedListReversal.java

@@ -0,0 +1,30 @@
+package com.baeldung.algorithms.linkedlist;
+
+public class LinkedListReversal {
+
+    ListNode reverseList(ListNode head) {
+        ListNode previous = null;
+        ListNode current = head;
+        while (current != null) {
+            ListNode nextElement = current.getNext();
+            current.setNext(previous);
+            previous = current;
+            current = nextElement;
+        }
+        return previous;
+    }
+
+    ListNode reverseListRecursive(ListNode head) {
+        if (head == null) {
+            return null;
+        }
+        if (head.getNext() == null) {
+            return head;
+        }
+        ListNode node = reverseListRecursive(head.getNext());
+        head.getNext().setNext(head);
+        head.setNext(null);
+        return node;
+    }
+
+}

algorithms-miscellaneous-6/src/main/java/com/baeldung/algorithms/linkedlist/ListNode.java

@@ -0,0 +1,28 @@
+package com.baeldung.algorithms.linkedlist;
+
+public class ListNode {
+
+    private int data;
+    private ListNode next;
+
+    ListNode(int data) {
+        this.data = data;
+        this.next = null;
+    }
+
+    public int getData() {
+        return data;
+    }
+
+    public ListNode getNext() {
+        return next;
+    }
+
+    public void setData(int data) {
+        this.data = data;
+    }
+
+    public void setNext(ListNode next) {
+        this.next = next;
+    }
+}

algorithms-miscellaneous-6/src/test/java/com/baeldung/algorithms/linkedlist/LinkedListReversalUnitTest.java

@@ -0,0 +1,59 @@
+package com.baeldung.algorithms.linkedlist;
+
+import org.junit.Test;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+
+public class LinkedListReversalUnitTest {
+    @Test
+    public void givenLinkedList_whenIterativeReverse_thenOutputCorrectResult() {
+        ListNode head = constructLinkedList();
+        ListNode node = head;
+        for (int i = 1; i <= 5; i++) {
+            assertNotNull(node);
+            assertEquals(i, node.getData());
+            node = node.getNext();
+        }
+        LinkedListReversal reversal = new LinkedListReversal();
+        node = reversal.reverseList(head);
+        for (int i = 5; i >= 1; i--) {
+            assertNotNull(node);
+            assertEquals(i, node.getData());
+            node = node.getNext();
+        }
+    }
+
+    @Test
+    public void givenLinkedList_whenRecursiveReverse_thenOutputCorrectResult() {
+        ListNode head = constructLinkedList();
+        ListNode node = head;
+        for (int i = 1; i <= 5; i++) {
+            assertNotNull(node);
+            assertEquals(i, node.getData());
+            node = node.getNext();
+        }
+        LinkedListReversal reversal = new LinkedListReversal();
+        node = reversal.reverseListRecursive(head);
+        for (int i = 5; i >= 1; i--) {
+            assertNotNull(node);
+            assertEquals(i, node.getData());
+            node = node.getNext();
+        }
+    }
+
+    private ListNode constructLinkedList() {
+        ListNode head = null;
+        ListNode tail = null;
+        for (int i = 1; i <= 5; i++) {
+            ListNode node = new ListNode(i);
+            if (head == null) {
+                head = node;
+            } else {
+                tail.setNext(node);
+            }
+            tail = node;
+        }
+        return head;
+    }
+}

apache-libraries/pom.xml

@@ -129,6 +129,11 @@
             <artifactId>zookeeper</artifactId>
             <version>${zookeeper.version}</version>
         </dependency>
+        <dependency>
+            <groupId>com.fasterxml.jackson.core</groupId>
+            <artifactId>jackson-core</artifactId>
+            <version>${jackson.version}</version>
+        </dependency>
         <dependency>
             <groupId>com.fasterxml.jackson.core</groupId>
             <artifactId>jackson-databind</artifactId>

apache-spark/src/main/java/com/baeldung/differences/dataframe/dataset/rdd/TouristData.java

@@ -0,0 +1,75 @@
+package com.baeldung.differences.dataframe.dataset.rdd;
+
+
+public class TouristData {
+
+    private String region;
+    private String country;
+    private String year;
+    private String series;
+    private Double value;
+    private String footnotes;
+    private String source;
+
+    public String getRegion() {
+        return region;
+    }
+
+    public void setRegion(String region) {
+        this.region = region;
+    }
+
+    public String getCountry() {
+        return country;
+    }
+
+    public void setCountry(String country) {
+        this.country = country;
+    }
+
+    public String getYear() {
+        return year;
+    }
+
+    public void setYear(String year) {
+        this.year = year;
+    }
+
+    public String getSeries() {
+        return series;
+    }
+
+    public void setSeries(String series) {
+        this.series = series;
+    }
+
+    public Double getValue() {
+        return value;
+    }
+
+    public void setValue(Double value) {
+        this.value = value;
+    }
+
+    public String getFootnotes() {
+        return footnotes;
+    }
+
+    public void setFootnotes(String footnotes) {
+        this.footnotes = footnotes;
+    }
+
+    public String getSource() {
+        return source;
+    }
+
+    public void setSource(String source) {
+        this.source = source;
+    }
+
+    @Override
+    public String toString() {
+        return "TouristData [region=" + region + ", country=" + country + ", year=" + year + ", series=" + series + ", value=" + value + ", footnotes=" + footnotes + ", source=" + source + "]";
+    }
+
+}

apache-spark/src/test/java/com/baeldung/differences/rdd/ActionsUnitTest.java

@@ -0,0 +1,67 @@
+package com.baeldung.differences.rdd;
+
+import static org.junit.Assert.assertEquals;
+
+import java.util.List;
+
+import org.apache.spark.SparkConf;
+import org.apache.spark.api.java.JavaPairRDD;
+import org.apache.spark.api.java.JavaRDD;
+import org.apache.spark.api.java.JavaSparkContext;
+import org.junit.AfterClass;
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+import scala.Tuple2;
+
+public class ActionsUnitTest {
+    private static JavaRDD<String> tourists;
+    private static JavaSparkContext sc;
+    public static final String COMMA_DELIMITER = ",(?=([^\"]*\"[^\"]*\")*[^\"]*$)";
+    
+    @BeforeClass
+    public static void init() {
+        SparkConf conf = new SparkConf().setAppName("reduce")
+            .setMaster("local[*]");
+        sc = new JavaSparkContext(conf);
+        tourists = sc.textFile("data/Tourist.csv").filter(line -> !line.startsWith("Region"));
+    }
+    
+    @AfterClass
+    public static void cleanup() {
+        sc.close();
+    }
+
+    @Test
+    public void whenDistinctCount_thenReturnDistinctNumRecords() {
+        JavaRDD<String> countries = tourists.map(line -> {
+            String[] columns = line.split(COMMA_DELIMITER);
+            return columns[1];
+        })
+            .distinct();
+        Long numberOfCountries = countries.count();
+        System.out.println("Count: " + numberOfCountries);
+        
+        assertEquals(Long.valueOf(220), numberOfCountries);
+    }
+    
+    @Test
+    public void whenReduceByKeySum_thenTotalValuePerKey() {
+        JavaRDD<String> touristsExpenditure = tourists.filter(line -> line.split(COMMA_DELIMITER)[3].contains("expenditure"));
+
+        JavaPairRDD<String, Double> expenditurePairRdd = touristsExpenditure.mapToPair(line -> {
+            String[] columns = line.split(COMMA_DELIMITER);
+            return new Tuple2<>(columns[1], Double.valueOf(columns[6]));
+        });
+        List<Tuple2<String, Double>> totalByCountry = expenditurePairRdd.reduceByKey((x, y) -> x + y)
+            .collect();
+        System.out.println("Total per Country: " + totalByCountry);
+        
+        for(Tuple2<String, Double> tuple : totalByCountry) {
+            if (tuple._1.equals("Mexico")) {
+                assertEquals(Double.valueOf(99164), tuple._2);
+            }
+        }
+    }
+
+}

apache-spark/src/test/java/com/baeldung/differences/rdd/DataFrameUnitTest.java

@@ -0,0 +1,74 @@
+package com.baeldung.differences.rdd;
+
+import static org.apache.spark.sql.functions.col;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+
+import java.util.Arrays;
+import java.util.List;
+
+import org.apache.spark.sql.DataFrameReader;
+import org.apache.spark.sql.Dataset;
+import org.apache.spark.sql.Row;
+import org.apache.spark.sql.SparkSession;
+import org.junit.AfterClass;
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+public class DataFrameUnitTest {
+    private static SparkSession session;
+    private static Dataset<Row> data;
+
+    @BeforeClass
+    public static void init() {
+        session = SparkSession.builder()
+            .appName("TouristDataFrameExample")
+            .master("local[*]")
+            .getOrCreate();
+        DataFrameReader dataFrameReader = session.read();
+        data = dataFrameReader.option("header", "true")
+            .csv("data/Tourist.csv");
+    }
+
+    @AfterClass
+    public static void cleanup() {
+        session.stop();
+    }
+
+    @Test
+    public void whenSelectSpecificColumns_thenColumnsFiltered() {
+        Dataset<Row> selectedData = data.select(col("country"), col("year"), col("value"));
+        selectedData.show();
+        
+        List<String> resultList = Arrays.asList(selectedData.columns());
+        assertTrue(resultList.contains("country"));
+        assertTrue(resultList.contains("year"));
+        assertTrue(resultList.contains("value"));
+        assertFalse(resultList.contains("Series"));
+
+    }
+
+    @Test
+    public void whenFilteringByCountry_thenCountryRecordsSelected() {
+        Dataset<Row> filteredData = data.filter(col("country").equalTo("Mexico"));
+        filteredData.show();
+        
+        filteredData.foreach(record -> {
+            assertEquals("Mexico", record.get(1));
+        });
+        
+    }
+
+    @Test
+    public void whenGroupCountByCountry_thenContryTotalRecords() {
+        Dataset<Row> recordsPerCountry = data.groupBy(col("country"))
+            .count();
+        recordsPerCountry.show();
+        
+        Dataset<Row> filteredData = recordsPerCountry.filter(col("country").equalTo("Sweden"));
+        assertEquals(new Long(12), filteredData.first()
+            .get(1));
+    }
+
+}

apache-spark/src/test/java/com/baeldung/differences/rdd/DatasetUnitTest.java

@@ -0,0 +1,83 @@
+package com.baeldung.differences.rdd;
+
+import static org.apache.spark.sql.functions.col;
+import static org.apache.spark.sql.functions.sum;
+import static org.junit.Assert.assertEquals;
+
+import org.apache.spark.api.java.function.FilterFunction;
+import org.apache.spark.sql.DataFrameReader;
+import org.apache.spark.sql.Dataset;
+import org.apache.spark.sql.Encoders;
+import org.apache.spark.sql.Row;
+import org.apache.spark.sql.SparkSession;
+import org.junit.AfterClass;
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+import com.baeldung.differences.dataframe.dataset.rdd.TouristData;
+
+public class DatasetUnitTest {
+    private static SparkSession session;
+    private static Dataset<TouristData> typedDataset;
+
+    @BeforeClass
+    public static void init() {
+        session = SparkSession.builder()
+            .appName("TouristDatasetExample")
+            .master("local[*]")
+            .getOrCreate();
+        DataFrameReader dataFrameReader = session.read();
+        Dataset<Row> data = dataFrameReader.option("header", "true")
+            .csv("data/Tourist.csv");
+        Dataset<Row> responseWithSelectedColumns = data.select(col("region"), 
+            col("country"), col("year"), col("series"), col("value").cast("double"), 
+            col("footnotes"), col("source"));
+        typedDataset = responseWithSelectedColumns.as(Encoders.bean(TouristData.class));
+    }
+
+    @AfterClass
+    public static void cleanup() {
+        session.stop();
+    }
+
+    @Test
+    public void whenFilteringByCountry_thenCountryRecordsSelected() {
+        Dataset<TouristData> selectedData = typedDataset
+            .filter((FilterFunction<TouristData>) record -> record.getCountry()
+            .equals("Norway"));
+        selectedData.show();
+
+        selectedData.foreach(record -> {
+            assertEquals("Norway", record.getCountry());
+        });
+    }
+
+    @Test
+    public void whenGroupCountByCountry_thenContryTotalRecords() {
+        Dataset<Row> countriesCount = typedDataset.groupBy(typedDataset.col("country"))
+            .count();
+        countriesCount.show();
+
+        assertEquals(Long.valueOf(220), Long.valueOf(countriesCount.count()));
+    }
+
+    @Test
+    public void whenFilteredByPropertyRange_thenRetreiveValidRecords() {
+        // Filter records with existing data for years between 2010 and 2017
+        typedDataset.filter((FilterFunction<TouristData>) record -> record.getYear() != null 
+            && (Long.valueOf(record.getYear()) > 2010 && Long.valueOf(record.getYear()) < 2017))
+            .show();
+    }
+    
+    @Test
+    public void whenSumValue_thenRetreiveTotalValue() {
+        // Total tourist expenditure by country
+        typedDataset.filter((FilterFunction<TouristData>) record -> record.getValue() != null 
+            && record.getSeries()
+            .contains("expenditure"))
+            .groupBy("country")
+            .agg(sum("value"))
+            .show();
+    }
+
+}

apache-spark/src/test/java/com/baeldung/differences/rdd/TransformationsUnitTest.java

@@ -0,0 +1,63 @@
+package com.baeldung.differences.rdd;
+
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+
+import org.apache.commons.lang3.StringUtils;
+import org.apache.spark.SparkConf;
+import org.apache.spark.api.java.JavaRDD;
+import org.apache.spark.api.java.JavaSparkContext;
+import org.junit.AfterClass;
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+public class TransformationsUnitTest {
+    
+    public static final String COMMA_DELIMITER = ",(?=([^\"]*\"[^\"]*\")*[^\"]*$)";
+    private static JavaSparkContext sc;
+    private static JavaRDD<String> tourists;
+    
+    @BeforeClass
+    public static void init() {
+        SparkConf conf = new SparkConf().setAppName("uppercaseCountries")
+            .setMaster("local[*]");
+        sc = new JavaSparkContext(conf);
+        tourists = sc.textFile("data/Tourist.csv")
+            .filter(line -> !line.startsWith("Region")); //filter header row
+    }
+    
+    @AfterClass
+    public static void cleanup() {
+        sc.close();
+    }
+
+    @Test
+    public void whenMapUpperCase_thenCountryNameUppercased() {
+        JavaRDD<String> upperCaseCountries = tourists.map(line -> {
+            String[] columns = line.split(COMMA_DELIMITER);
+            return columns[1].toUpperCase();
+        })
+            .distinct();
+        
+        upperCaseCountries.saveAsTextFile("data/output/uppercase.txt");
+        
+        upperCaseCountries.foreach(country -> {
+            //replace non alphanumerical characters
+            country = country.replaceAll("[^a-zA-Z]", "");
+            assertTrue(StringUtils.isAllUpperCase(country));
+        });
+    }
+
+    @Test
+    public void whenFilterByCountry_thenShowRequestedCountryRecords() {
+        JavaRDD<String> touristsInMexico = tourists.filter(line -> line.split(COMMA_DELIMITER)[1].equals("Mexico"));
+        
+        touristsInMexico.saveAsTextFile("data/output/touristInMexico.txt");
+        
+        touristsInMexico.foreach(record -> {
+            assertEquals("Mexico", record.split(COMMA_DELIMITER)[1]);
+        });
+    }
+
+}

core-java-modules/core-java-collections-3/README.md

@@ -13,3 +13,4 @@
 - [Quick Guide to the Java Stack](https://www.baeldung.com/java-stack)
 - [Convert an Array of Primitives to a List](https://www.baeldung.com/java-primitive-array-to-list)
 - [A Guide to BitSet in Java](https://www.baeldung.com/java-bitset)
+- [Get the First Key and Value From a HashMap](https://www.baeldung.com/java-hashmap-get-first-entry)

core-java-modules/core-java-concurrency-basic-2/README.md

@@ -11,4 +11,5 @@ This module contains articles about basic Java concurrency
 - [Life Cycle of a Thread in Java](https://www.baeldung.com/java-thread-lifecycle)
 - [Guide to AtomicMarkableReference](https://www.baeldung.com/java-atomicmarkablereference)
 - [Why are Local Variables Thread-Safe in Java](https://www.baeldung.com/java-local-variables-thread-safe)
+- [How to Stop Execution After a Certain Time in Java](https://www.baeldung.com/java-stop-execution-after-certain-time)
 - [[<-- Prev]](/core-java-modules/core-java-concurrency-basic)

core-java-modules/core-java-io-3/README.md

@@ -11,4 +11,5 @@ This module contains articles about core Java input and output (IO)
 - [Java Files Open Options](https://www.baeldung.com/java-file-options)
 - [Creating Temporary Directories in Java](https://www.baeldung.com/java-temp-directories)
 - [Reading a Line at a Given Line Number From a File in Java](https://www.baeldung.com/java-read-line-at-number)
+- [Find the Last Modified File in a Directory with Java](https://www.baeldung.com/java-last-modified-file)
 - [[<-- Prev]](/core-java-modules/core-java-io-2)

core-java-modules/core-java-io-3/src/main/java/com/baeldung/lastmodifiedfile/LastModifiedFileApp.java

@@ -0,0 +1,61 @@
+package com.baeldung.lastmodifiedfile;
+
+import java.io.File;
+import java.io.FileFilter;
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.util.Arrays;
+import java.util.Optional;
+
+import org.apache.commons.io.comparator.LastModifiedFileComparator;
+import org.apache.commons.io.filefilter.FileFilterUtils;
+
+public class LastModifiedFileApp {
+
+    public static File findUsingIOApi(String sdir) {
+        File dir = new File(sdir);
+        if (dir.isDirectory()) {
+            Optional<File> opFile = Arrays.stream(dir.listFiles(File::isFile))
+              .max((f1, f2) -> Long.compare(f1.lastModified(), f2.lastModified()));
+
+            if (opFile.isPresent()) {
+                return opFile.get();
+            }
+        }
+
+        return null;
+    }
+
+    public static Path findUsingNIOApi(String sdir) throws IOException {
+        Path dir = Paths.get(sdir);
+        if (Files.isDirectory(dir)) {
+            Optional<Path> opPath = Files.list(dir)
+              .filter(p -> !Files.isDirectory(p))
+              .sorted((p1, p2) -> Long.valueOf(p2.toFile().lastModified())
+                .compareTo(p1.toFile().lastModified()))
+              .findFirst();
+
+            if (opPath.isPresent()) {
+                return opPath.get();
+            }
+        }
+
+        return null;
+    }
+
+    public static File findUsingCommonsIO(String sdir) {
+        File dir = new File(sdir);
+        if (dir.isDirectory()) {
+            File[] dirFiles = dir.listFiles((FileFilter) FileFilterUtils.fileFileFilter());
+            if (dirFiles != null && dirFiles.length > 0) {
+                Arrays.sort(dirFiles, LastModifiedFileComparator.LASTMODIFIED_REVERSE);
+                return dirFiles[0];
+            }
+        }
+
+        return null;
+    }
+
+}

core-java-modules/core-java-io-3/src/test/java/com/baeldung/createfile/CreateFileUnitTest.java

@@ -6,6 +6,7 @@ import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 
 import java.io.File;
+import java.io.FileOutputStream;
 import java.io.IOException;
 import java.nio.file.Files;
 import java.nio.file.Path;
@@ -37,6 +38,12 @@ public class CreateFileUnitTest {
         assertTrue(success);
     }
 
+    @Test
+    void givenUsingFileOutputStream_whenCreatingFile_thenCorrect() throws IOException {
+        try(FileOutputStream fileOutputStream = new FileOutputStream(FILE_NAME)){
+        }
+    }
+
     @Test
     public void givenUsingGuava_whenCreatingFile_thenCorrect() throws IOException {
         com.google.common.io.Files.touch(new File(FILE_NAME));

core-java-modules/core-java-io-3/src/test/java/com/baeldung/lastmodifiedfile/LastModifiedFileAppUnitTest.java

@@ -0,0 +1,78 @@
+package com.baeldung.lastmodifiedfile;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import java.io.File;
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+
+import org.apache.commons.io.FileUtils;
+import org.junit.jupiter.api.AfterAll;
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.Test;
+
+public class LastModifiedFileAppUnitTest {
+
+    private final static String SOURCEDIRECTORY = "src/test/resources/lastmodfiles";
+
+    @BeforeAll
+    public static void setUpFiles() throws IOException, InterruptedException {
+        File srcDir = new File(SOURCEDIRECTORY);
+        if (!srcDir.exists()) {
+            srcDir.mkdir();
+        }
+
+        FileUtils.cleanDirectory(srcDir);
+
+        File file01 = new File(SOURCEDIRECTORY + "/file01.txt");
+        file01.createNewFile();
+
+        Thread.sleep(2000);
+
+        File file02 = new File(SOURCEDIRECTORY + "/file02.txt");
+        file02.createNewFile();
+
+        Thread.sleep(2000);
+
+        File file03 = new File(SOURCEDIRECTORY + "/file03.txt");
+        file03.createNewFile();
+
+        Thread.sleep(2000);
+
+        Files.write(Paths.get(SOURCEDIRECTORY + "/file02.txt"), "Hello File02".getBytes());
+
+    }
+
+    @Test
+    public void givenDirectory_whenUsingIoApi_thenFindLastModfile() throws IOException {
+        File lastModFile = LastModifiedFileApp.findUsingIOApi(SOURCEDIRECTORY);
+
+        assertThat(lastModFile).isNotNull();
+        assertThat(lastModFile.getName()).isEqualTo("file02.txt");
+    }
+
+    @Test
+    public void givenDirectory_whenUsingNioApi_thenFindLastModfile() throws IOException {
+        Path lastModPath = LastModifiedFileApp.findUsingNIOApi(SOURCEDIRECTORY);
+
+        assertThat(lastModPath).isNotNull();
+        assertThat(lastModPath.toFile().getName()).isEqualTo("file02.txt");
+    }
+
+    @Test
+    public void givenDirectory_whenUsingApacheCommons_thenFindLastModfile() throws IOException {
+        File lastModFile = LastModifiedFileApp.findUsingCommonsIO(SOURCEDIRECTORY);
+
+        assertThat(lastModFile).isNotNull();
+        assertThat(lastModFile.getName()).isEqualTo("file02.txt");
+    }
+
+    @AfterAll
+    public static void cleanUp() throws IOException {
+        File srcDir = new File(SOURCEDIRECTORY);
+        FileUtils.deleteDirectory(srcDir);
+    }
+
+}

core-java-modules/core-java-lang-3/README.md

@@ -6,4 +6,5 @@ This module contains articles about core features in the Java language
 - [Converting a Java String Into a Boolean](https://www.baeldung.com/java-string-to-boolean)
 - [When are Static Variables Initialized in Java?](https://www.baeldung.com/java-static-variables-initialization)
 - [Checking if a Class Exists in Java](https://www.baeldung.com/java-check-class-exists)
+- [The Difference Between a.getClass() and A.class in Java](https://www.baeldung.com/java-getclass-vs-class)
 - [[<-- Prev]](/core-java-modules/core-java-lang-2)

core-java-modules/core-java-lang-3/src/main/java/com/baeldung/getclassobject/Animal.java

@@ -0,0 +1,5 @@
+package com.baeldung.getclassobject;
+
+public class Animal {
+    protected int numberOfEyes;
+}

core-java-modules/core-java-lang-3/src/main/java/com/baeldung/getclassobject/Monkey.java

@@ -0,0 +1,4 @@
+package com.baeldung.getclassobject;
+
+public class Monkey extends Animal {
+}

core-java-modules/core-java-lang-3/src/main/java/com/baeldung/getclassobject/SomeAbstractClass.java

@@ -0,0 +1,4 @@
+package com.baeldung.getclassobject;
+
+public abstract class SomeAbstractClass {
+}

core-java-modules/core-java-lang-3/src/main/java/com/baeldung/getclassobject/SomeInterface.java

@@ -0,0 +1,4 @@
+package com.baeldung.getclassobject;
+
+interface SomeInterface {
+}

core-java-modules/core-java-lang-3/src/main/java/com/baeldung/getclassobject/SomeUtils.java

@@ -0,0 +1,9 @@
+package com.baeldung.getclassobject;
+
+public class SomeUtils {
+    private SomeUtils() {
+        throw new RuntimeException("This Util class is not allowed to be instantiated!");
+    }
+    //  public static utilMethods
+    //  ...
+}

core-java-modules/core-java-lang-3/src/test/java/com/baeldung/getclassobject/GetClassObjectUnitTest.java

@@ -0,0 +1,55 @@
+package com.baeldung.getclassobject;
+
+import org.junit.Test;
+
+import static org.junit.Assert.*;
+
+public class GetClassObjectUnitTest {
+    @Test
+    public void givenObjectAndType_whenGettingClassObject_thenTwoMethodsHaveTheSameResult() {
+        String str = "I am an object of the String class";
+        Class fromStrObject = str.getClass();
+        Class clazz = String.class;
+        assertSame(fromStrObject, clazz);
+    }
+
+    @Test
+    public void givenClassInheritance_whenGettingRuntimeTypeAndStaticType_thenGetDifferentResult() {
+        Animal animal = new Monkey();
+        Class runtimeType = animal.getClass();
+        Class staticType = Animal.class;
+        //Not equals
+        assertNotEquals(staticType, runtimeType);
+
+        Class monkeyClass = Monkey.class;
+        assertSame(runtimeType, monkeyClass);
+    }
+
+    @Test
+    public void givenPrimitiveType_whenGettingClassObject_thenOnlyStaticTypeWorks() {
+        int number = 7;
+        // Class numberClass = number.getClass();   <-- compilation error
+        Class intType = int.class;
+
+        assertNotNull(intType);
+        assertEquals("int", intType.getName());
+        assertTrue(intType.isPrimitive());
+    }
+
+    @Test
+    public void givenTypeCannotInstantiate_whenGetTypeStatically_thenGetTypesSuccefully() {
+        Class interfaceType = SomeInterface.class;
+        Class abstractClassType = SomeAbstractClass.class;
+        Class utilClassType = SomeUtils.class;
+
+        assertNotNull(interfaceType);
+        assertTrue(interfaceType.isInterface());
+        assertEquals("SomeInterface", interfaceType.getSimpleName());
+
+        assertNotNull(abstractClassType);
+        assertEquals("SomeAbstractClass", abstractClassType.getSimpleName());
+
+        assertNotNull(utilClassType);
+        assertEquals("SomeUtils", utilClassType.getSimpleName());
+    }
+}

core-java-modules/core-java-reflection-2/README.md

@@ -3,3 +3,4 @@
 - [Reading the Value of ‘private’ Fields from a Different Class in Java](https://www.baeldung.com/java-reflection-read-private-field-value)
 - [Set Field Value With Reflection](https://www.baeldung.com/java-set-private-field-value)
 - [Checking If a Method is Static Using Reflection in Java](https://www.baeldung.com/java-check-method-is-static)
+- [Checking if a Java Class is ‘abstract’ Using Reflection](https://www.baeldung.com/java-reflection-is-class-abstract)

core-java-modules/core-java-reflection-2/src/main/java/com/baeldung/reflection/check/abstractclass/AbstractExample.java

@@ -0,0 +1,15 @@
+package com.baeldung.reflection.check.abstractclass;
+
+import java.time.LocalDate;
+import java.time.LocalTime;
+
+public abstract class AbstractExample {
+
+    public static String getAuthorName() {
+        return "Umang Budhwar";
+    }
+
+    public abstract LocalDate getLocalDate();
+
+    public abstract LocalTime getLocalTime();
+}

core-java-modules/core-java-reflection-2/src/test/java/com/baeldung/reflection/check/abstractclass/AbstractExampleUnitTest.java

@@ -0,0 +1,16 @@
+package com.baeldung.reflection.check.abstractclass;
+
+import java.lang.reflect.Modifier;
+
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.Test;
+
+class AbstractExampleUnitTest {
+
+    @Test
+    void givenAbstractClass_whenCheckModifierIsAbstract_thenTrue() throws Exception {
+        Class<AbstractExample> clazz = AbstractExample.class;
+        Assertions.assertTrue(Modifier.isAbstract(clazz.getModifiers()));
+    }
+
+}

core-java-modules/core-java-security-2/README.md

@@ -10,4 +10,6 @@ This module contains articles about core Java Security
 - [SHA-256 and SHA3-256 Hashing in Java](https://www.baeldung.com/sha-256-hashing-java)
 - [Checksums in Java](https://www.baeldung.com/java-checksums)
 - [How to Read PEM File to Get Public and Private Keys](https://www.baeldung.com/java-read-pem-file-keys)
+- [Listing the Available Cipher Algorithms](https://www.baeldung.com/java-list-cipher-algorithms)
+- [Get a List of Trusted Certificates in Java](https://www.baeldung.com/java-list-trusted-certificates)
 - More articles: [[<-- prev]](/core-java-modules/core-java-security)

core-java-modules/core-java-security-2/src/test/java/com/baeldung/trustedcert/CertificatesUnitTest.java

@@ -0,0 +1,94 @@
+package com.baeldung.trustedcert;
+
+import org.junit.jupiter.api.Test;
+
+import javax.net.ssl.TrustManager;
+import javax.net.ssl.TrustManagerFactory;
+import javax.net.ssl.X509TrustManager;
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.IOException;
+import java.security.KeyStore;
+import java.security.KeyStoreException;
+import java.security.NoSuchAlgorithmException;
+import java.security.cert.Certificate;
+import java.security.cert.CertificateException;
+import java.security.cert.PKIXParameters;
+import java.security.cert.TrustAnchor;
+import java.security.cert.X509Certificate;
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.Enumeration;
+import java.util.List;
+import java.util.Set;
+import java.util.stream.Collectors;
+
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertTrue;
+
+public class CertificatesUnitTest {
+
+    private static final String GODADDY_CA_ALIAS = "godaddyrootg2ca [jdk]";
+
+    @Test
+    public void whenLoadingCacertsKeyStore_thenCertificatesArePresent() throws Exception {
+        KeyStore keyStore = loadKeyStore();
+        PKIXParameters params = new PKIXParameters(keyStore);
+
+        Set<TrustAnchor> trustAnchors = params.getTrustAnchors();
+        List<Certificate> certificates = trustAnchors.stream()
+          .map(TrustAnchor::getTrustedCert)
+          .collect(Collectors.toList());
+
+        assertFalse(certificates.isEmpty());
+    }
+
+    @Test
+    public void whenLoadingDefaultKeyStore_thenCertificatesArePresent() throws Exception {
+        TrustManagerFactory trustManagerFactory = TrustManagerFactory.getInstance(TrustManagerFactory.getDefaultAlgorithm());
+        trustManagerFactory.init((KeyStore)null);
+
+        List<TrustManager> trustManagers = Arrays.asList(trustManagerFactory.getTrustManagers());
+        List<X509Certificate> certificates = trustManagers.stream()
+          .filter(X509TrustManager.class::isInstance)
+          .map(X509TrustManager.class::cast)
+          .map(trustManager -> Arrays.asList(trustManager.getAcceptedIssuers()))
+          .flatMap(Collection::stream)
+          .collect(Collectors.toList());
+
+        assertFalse(certificates.isEmpty());
+    }
+
+    @Test
+    public void whenLoadingKeyStore_thenGoDaddyCALabelIsPresent() throws Exception {
+        KeyStore keyStore = loadKeyStore();
+
+        Enumeration<String> aliasEnumeration = keyStore.aliases();
+        List<String> aliases = Collections.list(aliasEnumeration);
+
+        assertTrue(aliases.contains(GODADDY_CA_ALIAS));
+    }
+
+    @Test
+    public void whenLoadingKeyStore_thenGoDaddyCertificateIsPresent() throws Exception {
+        KeyStore keyStore = loadKeyStore();
+
+        Certificate goDaddyCertificate = keyStore.getCertificate(GODADDY_CA_ALIAS);
+
+        assertNotNull(goDaddyCertificate);
+    }
+
+    private KeyStore loadKeyStore() throws CertificateException, NoSuchAlgorithmException, IOException, KeyStoreException {
+        String relativeCacertsPath = "/lib/security/cacerts".replace("/", File.separator);
+        String filename = System.getProperty("java.home") + relativeCacertsPath;
+        FileInputStream is = new FileInputStream(filename);
+
+        KeyStore keystore = KeyStore.getInstance(KeyStore.getDefaultType());
+        String password = "changeit";
+        keystore.load(is, password.toCharArray());
+
+        return keystore;
+    }
+}

core-kotlin-modules/core-kotlin-lang/src/main/kotlin/com/baeldung/inline/Inline.kt

@@ -22,30 +22,6 @@ fun main() {
     numbers.each { println(random * it) } // capturing the random variable
 }
 
-fun namedFunction(): Int {
-    return 42
-}
-
-fun anonymous(): () -> Int {
-    return fun(): Int {
-        return 42
-    }
-}
-
-inline fun <T> List<T>.eachIndexed(f: (Int, T) -> Unit) {
-    for (i in indices) {
-        f(i, this[i])
-    }
-}
-
-fun <T> List<T>.indexOf(x: T): Int {
-    eachIndexed { index, value ->
-        if (value == x) return index
-    }
-
-    return -1
-}
-
 /**
  * Generates a random number.
  */

core-kotlin-modules/core-kotlin/README.md

@@ -12,3 +12,4 @@ This module contains articles about Kotlin core features.
 - [Sequences in Kotlin](https://www.baeldung.com/kotlin/sequences)
 - [Converting Kotlin Data Class from JSON using GSON](https://www.baeldung.com/kotlin-json-convert-data-class)
 - [Exception Handling in Kotlin](https://www.baeldung.com/kotlin/exception-handling)
+- [Quick Guide to Kotlin Default and Named Arguments](https://www.baeldung.com/kotlin/default-named-arguments)

core-kotlin-modules/core-kotlin/src/main/kotlin/com/baeldung/arguments/DefaultArguments.kt

@@ -0,0 +1,37 @@
+package com.baeldung.arguments
+
+fun main() {
+
+    // Skip both the connectTimeout and enableRetry arguments
+    connect("http://www.baeldung.com")
+
+    // Skip only the enableRetry argument:
+    connect("http://www.baeldung.com", 5000)
+
+    // Skip only the middle argument connectTimeout
+    // connect("http://www.baeldung.com", false) // This results in a compiler error
+
+    // Because we skipped the connectTimeout argument, we must pass the enableRetry as a named argument
+    connect("http://www.baeldung.com", enableRetry = false)
+
+    // Overriding Functions and Default Arguments
+    val realConnector = RealConnector()
+    realConnector.connect("www.baeldung.com")
+    realConnector.connect()
+}
+
+fun connect(url: String, connectTimeout: Int = 1000, enableRetry: Boolean = true) {
+    println("The parameters are url = $url, connectTimeout = $connectTimeout, enableRetry = $enableRetry")
+}
+
+open class AbstractConnector {
+    open fun connect(url: String = "localhost") {
+        // function implementation
+    }
+}
+
+class RealConnector : AbstractConnector() {
+    override fun connect(url: String) {
+        println("The parameter is url = $url")
+    }
+}

core-kotlin-modules/core-kotlin/src/main/kotlin/com/baeldung/arguments/NamedArguments.kt

@@ -0,0 +1,28 @@
+package com.baeldung.arguments
+
+fun main() {
+    resizePane(newSize = 10, forceResize = true, noAnimation = false)
+
+    // Swap the order of last two named arguments
+    resizePane(newSize = 11, noAnimation = false, forceResize = true)
+
+    // Named arguments can be passed in any order
+    resizePane(forceResize = true, newSize = 12, noAnimation = false)
+
+    // Mixing Named and Positional Arguments
+    // Kotlin 1.3 would allow us to name only the arguments after the positional ones
+    resizePane(20, true, noAnimation = false)
+
+    // Using a positional argument in the middle of named arguments (supported from Kotlin 1.4.0)
+    // resizePane(newSize = 20, true, noAnimation = false)
+
+    // Only the last argument as a positional argument (supported from Kotlin 1.4.0)
+    // resizePane(newSize = 30, forceResize = true, false)
+
+    // Use a named argument in the middle of positional arguments (supported from Kotlin 1.4.0)
+    // resizePane(40, forceResize = true, false)
+}
+
+fun resizePane(newSize: Int, forceResize: Boolean, noAnimation: Boolean) {
+    println("The parameters are newSize = $newSize, forceResize = $forceResize, noAnimation = $noAnimation")
+}

docker/README.md

@@ -1,4 +1,3 @@
 ## Relevant Articles:
 
 - [Introduction to Docker Compose](https://www.baeldung.com/docker-compose)
-- [Creating Docker Images with Spring Boot](https://www.baeldung.com/spring-boot-docker-images)

docker/docker-spring-boot/README.md

@@ -0,0 +1,3 @@
+### Relevant Articles:
+
+- [Creating Docker Images with Spring Boot](https://www.baeldung.com/spring-boot-docker-images)

feign/pom.xml

@@ -16,11 +16,6 @@
     </parent>
 
     <dependencies>
-        <dependency>
-            <groupId>io.github.openfeign</groupId>
-            <artifactId>feign-core</artifactId>
-            <version>${feign.version}</version>
-        </dependency>
         <dependency>
             <groupId>io.github.openfeign</groupId>
             <artifactId>feign-okhttp</artifactId>
@@ -44,21 +39,8 @@
         </dependency>
     </dependencies>
 
-    <build>
-        <pluginManagement>
-            <plugins>
-                <plugin>
-                    <groupId>org.springframework.boot</groupId>
-                    <artifactId>spring-boot-maven-plugin</artifactId>
-                    <version>${spring-boot-maven-plugin.version}</version>
-                </plugin>
-            </plugins>
-        </pluginManagement>
-    </build>
-
     <properties>
-        <feign.version>9.4.0</feign.version>
-        <spring-boot-maven-plugin.version>1.4.2.RELEASE</spring-boot-maven-plugin.version>
+        <feign.version>10.11</feign.version>
     </properties>
 
 </project>

feign/src/test/java/com/baeldung/feign/clients/BookClientLiveTest.java

@@ -6,8 +6,6 @@ import com.baeldung.feign.models.BookResource;
 import lombok.extern.slf4j.Slf4j;
 import org.junit.Before;
 import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
 
 import java.util.List;
 import java.util.UUID;
@@ -22,7 +20,6 @@ import static org.junit.Assert.assertTrue;
  * Consumes https://github.com/Baeldung/spring-hypermedia-api
  */
 @Slf4j
-@RunWith(JUnit4.class)
 public class BookClientLiveTest {
     private BookClient bookClient;
 

gradle/gradle-wrapper/README.md

@@ -0,0 +1,3 @@
+### Relevant Articles:
+
+- [Guide to the Gradle Wrapper](https://www.baeldung.com/gradle-wrapper)

httpclient-2/README.md

@@ -8,5 +8,7 @@ The "REST With Spring" Classes: http://bit.ly/restwithspring
 
 ### Relevant Articles: 
 
-- [How to Set TLS Version in Apache HttpClient](https://www.baeldung.com/TODO)
+- [How to Set TLS Version in Apache HttpClient](https://www.baeldung.com/apache-httpclient-tls)
+- [Reading an HTTP Response Body as a String in Java](https://www.baeldung.com/java-http-response-body-as-string)
+- [How To Get Cookies From the Apache HttpClient Response](https://www.baeldung.com/java-apache-httpclient-cookies)
 - More articles: [[<-- prev]](../httpclient)

httpclient-2/pom.xml

@@ -4,6 +4,7 @@
     <modelVersion>4.0.0</modelVersion>
     <artifactId>httpclient-2</artifactId>
     <version>0.1-SNAPSHOT</version>
+    <name>httpclient-2</name>
 
     <parent>
         <groupId>com.baeldung</groupId>
@@ -13,6 +14,7 @@
     </parent>
 
     <dependencies>
+        <!-- http client -->
         <dependency>
             <groupId>org.apache.httpcomponents</groupId>
             <artifactId>httpclient</artifactId>
@@ -24,6 +26,19 @@
                 </exclusion>
             </exclusions>
         </dependency>
+
+        <!-- rest template -->
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-web</artifactId>
+            <version>${spring-boot.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-test</artifactId>
+            <version>${spring-boot.version}</version>
+            <scope>test</scope>
+        </dependency>
     </dependencies>
 
     <build>
@@ -34,10 +49,24 @@
                 <filtering>true</filtering>
             </resource>
         </resources>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-compiler-plugin</artifactId>
+                <version>${maven-compiler-plugin.version}</version>
+                <configuration>
+                    <source>${maven.compiler.source.version}</source>
+                    <target>${maven.compiler.target.version}</target>
+                </configuration>
+            </plugin>
+        </plugins>
     </build>
 
     <properties>
         <httpclient.version>4.5.8</httpclient.version>
+        <maven.compiler.source.version>11</maven.compiler.source.version>
+        <maven.compiler.target.version>11</maven.compiler.target.version>
+        <spring-boot.version>2.1.7.RELEASE</spring-boot.version>
     </properties>
 
 </project>

httpclient-2/src/test/java/com/baeldung/httpclient/cookies/HttpClientGettingCookieValueUnitTest.java

@@ -0,0 +1,54 @@
+package com.baeldung.httpclient.cookies;
+
+import org.apache.http.client.CookieStore;
+import org.apache.http.client.methods.CloseableHttpResponse;
+import org.apache.http.client.methods.HttpGet;
+import org.apache.http.client.protocol.HttpClientContext;
+import org.apache.http.cookie.Cookie;
+import org.apache.http.impl.client.BasicCookieStore;
+import org.apache.http.impl.client.CloseableHttpClient;
+import org.apache.http.impl.client.HttpClients;
+import org.apache.http.impl.cookie.BasicClientCookie;
+import org.junit.Test;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.io.IOException;
+
+import static org.junit.Assert.assertEquals;
+
+
+public class HttpClientGettingCookieValueUnitTest {
+    private static Logger log = LoggerFactory.getLogger(HttpClientGettingCookieValueUnitTest.class);
+
+    private static final String SAMPLE_URL = "http://www.baeldung.com/";
+
+    @Test
+    public final void whenSettingCustomCookieOnTheRequest_thenGettingTheSameCookieFromTheResponse() throws IOException {
+        HttpClientContext context = HttpClientContext.create();
+        context.setAttribute(HttpClientContext.COOKIE_STORE, createCustomCookieStore());
+
+        try (CloseableHttpClient httpClient = HttpClients.createDefault()) {
+            try (CloseableHttpResponse response = httpClient.execute(new HttpGet(SAMPLE_URL), context)) {
+                CookieStore cookieStore = context.getCookieStore();
+                Cookie customCookie = cookieStore.getCookies()
+                  .stream()
+                  .peek(cookie -> log.info("cookie name:{}", cookie.getName()))
+                  .filter(cookie -> "custom_cookie".equals(cookie.getName()))
+                  .findFirst()
+                  .orElseThrow(IllegalStateException::new);
+
+                assertEquals("test_value", customCookie.getValue());
+            }
+        }
+    }
+
+    private BasicCookieStore createCustomCookieStore() {
+        BasicCookieStore cookieStore = new BasicCookieStore();
+        BasicClientCookie cookie = new BasicClientCookie("custom_cookie", "test_value");
+        cookie.setDomain("baeldung.com");
+        cookie.setPath("/");
+        cookieStore.addCookie(cookie);
+        return cookieStore;
+    }
+}

httpclient-2/src/test/java/com/baeldung/httpclient/readresponsebodystring/ApacheHttpClientUnitTest.java

@@ -0,0 +1,26 @@
+package com.baeldung.httpclient.readresponsebodystring;
+
+import org.apache.http.HttpEntity;
+import org.apache.http.client.methods.CloseableHttpResponse;
+import org.apache.http.client.methods.HttpGet;
+import org.apache.http.impl.client.CloseableHttpClient;
+import org.apache.http.impl.client.HttpClients;
+import org.apache.http.util.EntityUtils;
+import org.junit.Test;
+
+import java.io.IOException;
+
+public class ApacheHttpClientUnitTest {
+    public static final String DUMMY_URL = "https://postman-echo.com/get";
+
+    @Test
+    public void whenUseApacheHttpClient_thenCorrect() throws IOException {
+        HttpGet request = new HttpGet(DUMMY_URL);
+
+        try (CloseableHttpClient client = HttpClients.createDefault(); CloseableHttpResponse response = client.execute(request)) {
+            HttpEntity entity = response.getEntity();
+            String result = EntityUtils.toString(entity);
+            System.out.println("Response -> " + result);
+        }
+    }
+}

httpclient-2/src/test/java/com/baeldung/httpclient/readresponsebodystring/HttpClientUnitTest.java

@@ -0,0 +1,29 @@
+package com.baeldung.httpclient.readresponsebodystring;
+
+import org.junit.Test;
+
+import java.io.IOException;
+import java.net.URI;
+import java.net.http.HttpClient;
+import java.net.http.HttpRequest;
+import java.net.http.HttpResponse;
+
+public class HttpClientUnitTest {
+    public static final String DUMMY_URL = "https://postman-echo.com/get";
+
+    @Test
+    public void whenUseHttpClient_thenCorrect() throws IOException, InterruptedException {
+        HttpClient client = HttpClient.newHttpClient();
+        HttpRequest request = HttpRequest.newBuilder().uri(URI.create(DUMMY_URL)).build();
+
+        // synchronous response
+        HttpResponse<String> response = client.send(request, HttpResponse.BodyHandlers.ofString());
+        System.out.println(response.body());
+
+        // asynchronous response
+        client.sendAsync(request, HttpResponse.BodyHandlers.ofString())
+            .thenApply(HttpResponse::body)
+            .thenAccept(System.out::println)
+            .join();
+    }
+}

httpclient-2/src/test/java/com/baeldung/httpclient/readresponsebodystring/HttpUrlConnectionUnitTest.java

@@ -0,0 +1,34 @@
+package com.baeldung.httpclient.readresponsebodystring;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.net.HttpURLConnection;
+import java.net.URL;
+
+public class HttpUrlConnectionUnitTest {
+
+    public static final String DUMMY_URL = "https://postman-echo.com/get";
+
+    @Test
+    public void whenUseHttpUrlConnection_thenCorrect() throws IOException {
+        HttpURLConnection connection = (HttpURLConnection) new URL(DUMMY_URL).openConnection();
+
+        InputStream inputStream = connection.getInputStream();
+
+        BufferedReader in = new BufferedReader(new InputStreamReader(inputStream));
+        StringBuilder response = new StringBuilder();
+        String currentLine;
+
+        while ((currentLine = in.readLine()) != null)
+            response.append(currentLine);
+
+        in.close();
+        Assert.assertNotNull(response.toString());
+        System.out.println("Response -> " + response.toString());
+    }
+}

httpclient-2/src/test/java/com/baeldung/httpclient/readresponsebodystring/SpringRestTemplateUnitTest.java

@@ -0,0 +1,17 @@
+package com.baeldung.httpclient.readresponsebodystring;
+
+import org.junit.Test;
+import org.springframework.web.client.RestTemplate;
+
+public class SpringRestTemplateUnitTest {
+
+    public static final String DUMMY_URL = "https://postman-echo.com/get";
+
+    @Test
+    public void whenUseRestTemplate_thenCorrect() {
+        RestTemplate restTemplate = new RestTemplate();
+        String response = restTemplate.getForObject(DUMMY_URL, String.class);
+        System.out.println(response);
+    }
+
+}

jackson-modules/jackson-custom-conversions/pom.xml

@@ -23,6 +23,13 @@
             <artifactId>jackson-datatype-joda</artifactId>
             <version>${jackson.version}</version>
         </dependency>
+        <dependency>
+            <groupId>com.fasterxml.jackson.core</groupId>
+            <artifactId>jackson-core</artifactId>
+            <version>${jackson.version}</version>
+        </dependency>
+
+
     </dependencies>
 
     <build>

jackson-modules/jackson-custom-conversions/src/test/java/com/baeldung/deserialization/CustomDeserializationUnitTest.java

@@ -60,8 +60,6 @@ public class CustomDeserializationUnitTest {
         String converted = objectMapper.writeValueAsString(now);
         // restore an instance of ZonedDateTime from String
         ZonedDateTime restored = objectMapper.readValue(converted, ZonedDateTime.class);
-        System.out.println("serialized: " + now);
-        System.out.println("restored: " + restored);
         assertThat(now, is(not(restored)));
     }
 
@@ -70,15 +68,14 @@ public class CustomDeserializationUnitTest {
         ObjectMapper objectMapper = new ObjectMapper();
         objectMapper.findAndRegisterModules();
         objectMapper.disable(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS);
+        objectMapper.enable(SerializationFeature.WRITE_DATES_WITH_ZONE_ID);
         objectMapper.disable(DeserializationFeature.ADJUST_DATES_TO_CONTEXT_TIME_ZONE);
         // construct a new instance of ZonedDateTime
         ZonedDateTime now = ZonedDateTime.now(ZoneId.of("Europe/Berlin"));
         String converted = objectMapper.writeValueAsString(now);
         // restore an instance of ZonedDateTime from String
         ZonedDateTime restored = objectMapper.readValue(converted, ZonedDateTime.class);
-        System.out.println("serialized: " + now);
-        System.out.println("restored: " + restored);
-        assertThat(now, is(restored));
+        assertThat(restored, is(now));
     }
 
 }

jackson-modules/jackson-custom-conversions/src/test/java/com/baeldung/serialization/CustomSerializationUnitTest.java

@@ -24,7 +24,6 @@ public class CustomSerializationUnitTest {
     public final void whenSerializing_thenNoExceptions() throws JsonGenerationException, JsonMappingException, IOException {
         final Item myItem = new Item(1, "theItem", new User(2, "theUser"));
         final String serialized = new ObjectMapper().writeValueAsString(myItem);
-        System.out.println(serialized);
     }
 
     @Test
@@ -38,7 +37,6 @@ public class CustomSerializationUnitTest {
         mapper.registerModule(simpleModule);
 
         final String serialized = mapper.writeValueAsString(myItem);
-        System.out.println(serialized);
     }
 
     @Test
@@ -46,7 +44,6 @@ public class CustomSerializationUnitTest {
         final ItemWithSerializer myItem = new ItemWithSerializer(1, "theItem", new User(2, "theUser"));
 
         final String serialized = new ObjectMapper().writeValueAsString(myItem);
-        System.out.println(serialized);
     }
 
 }

jackson-modules/jackson-custom-conversions/src/test/java/com/baeldung/skipfields/IgnoreFieldsWithFilterUnitTest.java

@@ -37,7 +37,6 @@ public class IgnoreFieldsWithFilterUnitTest {
         assertThat(dtoAsString, not(containsString("intValue")));
         assertThat(dtoAsString, containsString("booleanValue"));
         assertThat(dtoAsString, containsString("stringValue"));
-        System.out.println(dtoAsString);
     }
 
     @Test
@@ -83,7 +82,6 @@ public class IgnoreFieldsWithFilterUnitTest {
         assertThat(dtoAsString, not(containsString("intValue")));
         assertThat(dtoAsString, containsString("booleanValue"));
         assertThat(dtoAsString, containsString("stringValue"));
-        System.out.println(dtoAsString);
     }
 
 }

jackson-modules/jackson-custom-conversions/src/test/java/com/baeldung/skipfields/JacksonDynamicIgnoreUnitTest.java

@@ -51,8 +51,6 @@ public class JacksonDynamicIgnoreUnitTest {
         assertTrue(result.contains("john"));
         assertTrue(result.contains("address"));
         assertTrue(result.contains("usa"));
-
-        System.out.println("Not Hidden = " + result);
     }
 
     @Test
@@ -65,8 +63,6 @@ public class JacksonDynamicIgnoreUnitTest {
         assertTrue(result.contains("john"));
         assertFalse(result.contains("address"));
         assertFalse(result.contains("usa"));
-
-        System.out.println("Address Hidden = " + result);
     }
 
     @Test
@@ -76,8 +72,6 @@ public class JacksonDynamicIgnoreUnitTest {
         final String result = mapper.writeValueAsString(person);
 
         assertTrue(result.length() == 0);
-
-        System.out.println("All Hidden = " + result);
     }
 
     @Test
@@ -90,7 +84,5 @@ public class JacksonDynamicIgnoreUnitTest {
         final Person p3 = new Person("adam", ad3, false);
 
         final String result = mapper.writeValueAsString(Arrays.asList(p1, p2, p3));
-
-        System.out.println(result);
     }
 }

java-native/README.md

@@ -5,3 +5,4 @@ This module contains articles about the Java Native Interface (JNI).
 ### Relevant Articles: 
 
 - [Guide to JNI (Java Native Interface)](https://www.baeldung.com/jni)
+- [Using JNA to Access Native Dynamic Libraries](https://www.baeldung.com/java-jna-dynamic-libraries)

java-native/pom.xml

@@ -0,0 +1,39 @@
+<?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>
+    <artifactId>java-native</artifactId>
+    <name>java-native</name>
+
+    <parent>
+        <groupId>com.baeldung</groupId>
+        <artifactId>parent-modules</artifactId>
+        <version>1.0.0-SNAPSHOT</version>
+    </parent>
+
+    <properties>
+        <jna.version>5.6.0</jna.version>
+    </properties>
+
+    <dependencies>
+        <dependency>
+            <groupId>net.java.dev.jna</groupId>
+            <artifactId>jna-platform</artifactId>
+            <version>${jna.version}</version>
+        </dependency>
+    </dependencies>
+    
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-surefire-plugin</artifactId>
+                <configuration>
+                    <!-- we don't want to reuse JVMs here ! -->
+                    <reuseForks>false</reuseForks>
+                </configuration>
+            </plugin>
+        </plugins>
+    </build>
+</project>

java-native/src/main/java/com/baeldung/jna/CMath.java

@@ -0,0 +1,10 @@
+package com.baeldung.jna;
+
+import com.sun.jna.Library;
+import com.sun.jna.Native;
+import com.sun.jna.Platform;
+
+public interface CMath extends Library {
+    CMath INSTANCE = Native.load(Platform.isWindows() ? "msvcrt" : "c", CMath.class);
+    double cosh(double value);
+}

java-native/src/main/java/com/baeldung/jna/Main.java

@@ -0,0 +1,8 @@
+package com.baeldung.jna;
+
+public class Main {
+	
+	public static void main(String[] args) {
+		
+	}
+}

java-native/src/main/java/com/baeldung/jna/NativeFS.java

@@ -0,0 +1,46 @@
+package com.baeldung.jna;
+
+import java.util.Collections;
+import java.util.Map;
+
+import com.sun.jna.FunctionMapper;
+import com.sun.jna.LastErrorException;
+import com.sun.jna.Library;
+import com.sun.jna.Native;
+import com.sun.jna.NativeLong;
+import com.sun.jna.Platform;
+import com.sun.jna.Structure;
+import com.sun.jna.Structure.FieldOrder;
+
+public interface NativeFS extends Library {
+    
+    FunctionMapper mapper = (library,method) -> {
+        if (Platform.isWindows()) {
+            return "_" + method.getName();
+        }
+        else {
+            return "__x" + method.getName(); // On Linux, stat is actually _xstat
+        }
+    };
+    
+    public NativeFS INSTANCE = Native.load(Platform.isWindows() ? "msvcrt" : "c",
+      NativeFS.class,
+      Collections.singletonMap(Library.OPTION_FUNCTION_MAPPER, mapper));
+
+    int stat(String path, Stat stat) throws LastErrorException;
+
+    @FieldOrder({"st_dev","st_ino","st_mode","st_nlink","st_uid","st_gid","st_rdev","st_size","st_atime","st_mtime","st_ctime"})
+    public class Stat extends Structure {
+        public int st_dev;
+        public int st_ino;
+        public short st_mode;
+        public short st_nlink;
+        public short st_uid;
+        public short st_gid;
+        public int st_rdev;
+        public NativeLong st_size;
+        public NativeLong st_atime;
+        public NativeLong st_mtime;
+        public NativeLong st_ctime;
+    }
+}

java-native/src/main/java/com/baeldung/jna/StdC.java

@@ -0,0 +1,17 @@
+package com.baeldung.jna;
+
+import com.sun.jna.LastErrorException;
+import com.sun.jna.Library;
+import com.sun.jna.Native;
+import com.sun.jna.Platform;
+import com.sun.jna.Pointer;
+
+public interface StdC extends Library {
+    StdC INSTANCE = Native.load(Platform.isWindows() ? "msvcrt" : "c", StdC.class );
+    Pointer malloc(long n);
+    void free(Pointer p);
+    Pointer memset(Pointer p, int c, long n);
+    int open(String path, int flags) throws LastErrorException;
+    int close(int fd) throws LastErrorException;
+}
+

java-native/src/test/java/com/baeldung/jna/CMathUnitTest.java

@@ -0,0 +1,18 @@
+package com.baeldung.jna;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+import org.junit.jupiter.api.Test;
+
+import com.sun.jna.Native;
+import com.sun.jna.Platform;
+
+class CMathUnitTest {
+    @Test
+    void whenCallNative_thenSuccess() {
+        CMath lib = Native.load(Platform.isWindows() ? "msvcrt" : "c", CMath.class);
+        double result = lib.cosh(0);
+        assertEquals(1.0,result);
+    }
+
+}

java-native/src/test/java/com/baeldung/jna/NativeFSUnitTest.java

@@ -0,0 +1,38 @@
+package com.baeldung.jna;
+
+import static org.junit.Assert.fail;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import java.io.File;
+import java.io.IOException;
+import java.nio.file.Files;
+
+import org.junit.jupiter.api.Test;
+
+import com.baeldung.jna.NativeFS.Stat;
+import com.sun.jna.LastErrorException;
+import com.sun.jna.Platform;
+
+public class NativeFSUnitTest {
+    
+
+    @Test
+    public void whenCallNative_thenSuccess() throws IOException {
+        NativeFS lib = NativeFS.INSTANCE;
+        
+        File f = Files.createTempFile("junit", ".bin").toFile(); 
+        f.deleteOnExit();
+        Stat stat = new Stat();
+        try {
+            if (Platform.isWindows()) {
+                int rc = lib.stat(f.getAbsolutePath(), stat);
+                assertEquals(0, rc);
+                assertEquals(0,stat.st_size.longValue());
+            }
+        }
+        catch(LastErrorException error) {
+            fail("stat failed: error code=" + error.getErrorCode());
+        }
+        
+    }
+}

java-native/src/test/java/com/baeldung/jna/StdCUnitTest.java

@@ -0,0 +1,47 @@
+package com.baeldung.jna;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+import org.junit.BeforeClass;
+import org.junit.jupiter.api.Test;
+
+import com.sun.jna.Native;
+import com.sun.jna.Platform;
+import com.sun.jna.Pointer;
+
+class StdCUnitTest {
+    
+    @BeforeClass
+    public static void setupProtectedMode() {
+        Native.setProtected(true);
+    }
+
+    @Test
+    public void whenMalloc_thenSuccess() {
+        StdC lib = StdC.INSTANCE;
+        Pointer p = lib.malloc(1024);
+        p.setMemory(0l, 1024l, (byte) 0);
+        lib.free(p);
+    }
+    
+    @Test
+    public void whenAccessViolation_thenShouldThrowError() {
+        // Running this test on Linux requires additional setup using libjsig.so
+        // Details here: http://java-native-access.github.io/jna/5.6.0/javadoc/overview-summary.html#crash-protection
+        // IMPORTANT NOTICE: Code for illustration purposes only. DON'T DO THIS IN YOUR OWN CODE
+        if ( Platform.isWindows()) {
+            Error e = null;
+            Pointer p = new Pointer(0l);
+            
+            try {
+                p.setMemory(0, 100*1024, (byte) 0);
+            }
+            catch(Error err) {
+                e = err;
+            }
+            
+            assertNotNull(e, "Should throw Error");
+        }
+    }
+
+}

jni/pom.xml

@@ -1,14 +0,0 @@
-<?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>
-    <artifactId>jni</artifactId>
-    <name>jni</name>
-
-    <parent>
-        <groupId>com.baeldung</groupId>
-        <artifactId>parent-modules</artifactId>
-        <version>1.0.0-SNAPSHOT</version>
-    </parent>
-
-</project>

json-2/pom.xml

@@ -53,12 +53,12 @@
         <dependency>
             <groupId>com.fasterxml.jackson.core</groupId>
             <artifactId>jackson-annotations</artifactId>
-            <version>2.11.0</version>
+            <version>${jackson.version}</version>
         </dependency>
         <dependency>
             <groupId>com.fasterxml.jackson.core</groupId>
             <artifactId>jackson-databind</artifactId>
-            <version>2.11.0</version>
+            <version>${jackson.version}</version>
         </dependency>
         <dependency>
             <groupId>com.io-informatics.oss</groupId>

libraries-5/src/test/java/com/baeldung/pact/PactConsumerDrivenContractUnitTest.java

@@ -7,22 +7,38 @@ import au.com.dius.pact.consumer.dsl.PactDslWithProvider;
 import au.com.dius.pact.model.RequestResponsePact;
 import org.junit.Rule;
 import org.junit.Test;
-import org.springframework.http.HttpEntity;
-import org.springframework.http.HttpHeaders;
-import org.springframework.http.HttpMethod;
-import org.springframework.http.MediaType;
-import org.springframework.http.ResponseEntity;
+import org.springframework.http.*;
 import org.springframework.web.client.RestTemplate;
 
+import java.io.IOException;
+import java.net.ServerSocket;
 import java.util.HashMap;
 import java.util.Map;
+import java.util.Random;
 
 import static org.assertj.core.api.Assertions.assertThat;
 
 public class PactConsumerDrivenContractUnitTest {
 
+    private static int getAvailablePort() {
+        return new Random()
+            .ints(6000, 9000)
+            .filter(PactConsumerDrivenContractUnitTest::isFree)
+            .findFirst()
+            .orElse(8080);
+    }
+
+    private static boolean isFree(int port) {
+        try {
+            new ServerSocket(port).close();
+            return true;
+        } catch (IOException e) {
+            return false;
+        }
+    }
+
     @Rule
-    public PactProviderRuleMk2 mockProvider = new PactProviderRuleMk2("test_provider", "localhost", 8080, this);
+    public PactProviderRuleMk2 mockProvider = new PactProviderRuleMk2("test_provider", "localhost", getAvailablePort(), this);
 
     @Pact(consumer = "test_consumer")
     public RequestResponsePact createPact(PactDslWithProvider builder) {

libraries-6/README.md

@@ -16,4 +16,5 @@ Remember, for advanced libraries like [Jackson](/jackson) and [JUnit](/testing-m
 - [Exactly Once Processing in Kafka](https://www.baeldung.com/kafka-exactly-once)
 - [Introduction to Protonpack](https://www.baeldung.com/java-protonpack)
 - [Java-R Integration](https://www.baeldung.com/java-r-integration)
+- [Using libphonenumber to Validate Phone Numbers](https://www.baeldung.com/java-libphonenumber)
 - More articles [[<-- prev]](/libraries-5)

libraries-6/pom.xml

@@ -107,6 +107,12 @@
             <artifactId>renjin-script-engine</artifactId>
             <version>${renjin.version}</version>
         </dependency>
+        <!-- libphonenumber  -->
+        <dependency>
+            <groupId>com.googlecode.libphonenumber</groupId>
+            <artifactId>libphonenumber</artifactId>
+            <version>${libphonenumber.version}</version>
+        </dependency>        
     </dependencies>
 
     <repositories>
@@ -150,6 +156,7 @@
         <renjin.version>RELEASE</renjin.version>
         <rcaller.version>3.0</rcaller.version>
         <rserve.version>1.8.1</rserve.version>
+        <libphonenumber.version>8.12.9</libphonenumber.version>
     </properties>
 
 

libraries-6/src/test/java/com/baeldung/libphonenumber/LibPhoneNumberUnitTest.java

@@ -0,0 +1,79 @@
+package com.baeldung.libphonenumber;
+
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+
+import org.junit.Test;
+
+import com.google.i18n.phonenumbers.NumberParseException;
+import com.google.i18n.phonenumbers.PhoneNumberUtil;
+import com.google.i18n.phonenumbers.PhoneNumberUtil.PhoneNumberType;
+import com.google.i18n.phonenumbers.Phonenumber.PhoneNumber;
+import com.google.i18n.phonenumbers.Phonenumber.PhoneNumber.CountryCodeSource;
+
+public class LibPhoneNumberUnitTest {
+
+    private static final PhoneNumberUtil phoneNumberUtil = PhoneNumberUtil.getInstance();
+
+    @Test
+    public void givenPhoneNumber_whenValid_thenOK() throws Exception {
+
+        PhoneNumber phone = phoneNumberUtil.parse("+911234567890", CountryCodeSource.UNSPECIFIED.name());
+
+        assertTrue(phoneNumberUtil.isValidNumber(phone));
+        assertTrue(phoneNumberUtil.isValidNumberForRegion(phone, "IN"));
+        assertFalse(phoneNumberUtil.isValidNumberForRegion(phone, "US"));
+        assertTrue(phoneNumberUtil.isValidNumber(phoneNumberUtil.getExampleNumber("IN")));
+    }
+
+    @Test
+    public void givenPhoneNumber_whenAlphaNumber_thenValid() {
+        assertTrue(phoneNumberUtil.isAlphaNumber("325-CARS"));
+        assertTrue(phoneNumberUtil.isAlphaNumber("0800 REPAIR"));
+        assertTrue(phoneNumberUtil.isAlphaNumber("1-800-MY-APPLE"));
+        assertTrue(phoneNumberUtil.isAlphaNumber("1-800-MY-APPLE.."));
+        assertFalse(phoneNumberUtil.isAlphaNumber("+876 1234-1234"));
+    }
+
+    @Test
+    public void givenPhoneNumber_whenPossibleForType_thenValid() {
+        PhoneNumber number = new PhoneNumber();
+        number.setCountryCode(54);
+
+        number.setNationalNumber(123456);
+        assertTrue(phoneNumberUtil.isPossibleNumberForType(number, PhoneNumberType.FIXED_LINE));
+        assertFalse(phoneNumberUtil.isPossibleNumberForType(number, PhoneNumberType.TOLL_FREE));
+
+        number.setNationalNumber(12345678901L);
+        assertFalse(phoneNumberUtil.isPossibleNumberForType(number, PhoneNumberType.FIXED_LINE));
+        assertTrue(phoneNumberUtil.isPossibleNumberForType(number, PhoneNumberType.MOBILE));
+        assertFalse(phoneNumberUtil.isPossibleNumberForType(number, PhoneNumberType.TOLL_FREE));
+    }
+
+    @Test
+    public void givenPhoneNumber_whenPossible_thenValid() {
+        PhoneNumber number = new PhoneNumber();
+        number.setCountryCode(1)
+            .setNationalNumber(123000L);
+        assertFalse(phoneNumberUtil.isPossibleNumber(number));
+        assertFalse(phoneNumberUtil.isPossibleNumber("+1 343 253 00000", "US"));
+        assertFalse(phoneNumberUtil.isPossibleNumber("(343) 253-00000", "US"));
+        assertFalse(phoneNumberUtil.isPossibleNumber("dial p for pizza", "US"));
+        assertFalse(phoneNumberUtil.isPossibleNumber("123-000", "US"));
+    }
+
+    @Test
+    public void givenPhoneNumber_whenNumberGeographical_thenValid() throws NumberParseException {
+
+        PhoneNumber phone = phoneNumberUtil.parse("+911234567890", "IN");
+        assertTrue(phoneNumberUtil.isNumberGeographical(phone));
+
+        phone = new PhoneNumber().setCountryCode(1)
+            .setNationalNumber(2530000L);
+        assertFalse(phoneNumberUtil.isNumberGeographical(phone));
+
+        phone = new PhoneNumber().setCountryCode(800)
+            .setNationalNumber(12345678L);
+        assertFalse(phoneNumberUtil.isNumberGeographical(phone));
+    }
+}

libraries-data-2/pom.xml

@@ -168,7 +168,7 @@
         <crdt.version>0.1.0</crdt.version>
         <unit-ri.version>1.0.3</unit-ri.version>
         <infinispan.version>9.1.5.Final</infinispan.version>
-        <jackson.version>2.9.8</jackson.version>
+<!--        <jackson.version>2.9.8</jackson.version>-->
         <spring.version>4.3.8.RELEASE</spring.version>
         <suanshu.version>4.0.0</suanshu.version>
         <derive4j.version>1.1.0</derive4j.version>

libraries-http-2/pom.xml

@@ -72,7 +72,7 @@
         <okhttp.version>3.14.2</okhttp.version>
         <gson.version>2.8.5</gson.version>
         <mockwebserver.version>3.14.2</mockwebserver.version>
-        <jackson.version>2.9.8</jackson.version>
+<!--        <jackson.version>2.9.8</jackson.version>-->
         <jetty.httpclient.version>1.0.3</jetty.httpclient.version>
         <jetty.server.version>9.4.19.v20190610</jetty.server.version>
         <rxjava2.version>2.2.11</rxjava2.version>

libraries-http/pom.xml

@@ -118,7 +118,7 @@
     <properties>
         <gson.version>2.8.5</gson.version>
         <httpclient.version>4.5.3</httpclient.version>
-        <jackson.version>2.9.8</jackson.version>
+<!--        <jackson.version>2.9.8</jackson.version>-->
         <assertj.version>3.6.2</assertj.version>
         <com.squareup.okhttp3.version>3.14.2</com.squareup.okhttp3.version>
         <googleclient.version>1.23.0</googleclient.version>

metrics/pom.xml

@@ -66,12 +66,12 @@
         <dependency>
             <groupId>com.fasterxml.jackson.core</groupId>
             <artifactId>jackson-databind</artifactId>
-            <version>${fasterxml.jackson.version}</version>
+            <version>${jackson.version}</version>
         </dependency>
         <dependency>
             <groupId>com.fasterxml.jackson.dataformat</groupId>
             <artifactId>jackson-dataformat-smile</artifactId>
-            <version>${fasterxml.jackson.version}</version>
+            <version>${jackson.version}</version>
         </dependency>
 
         <dependency>
@@ -93,7 +93,7 @@
         <dep.ver.servlet>3.1.0</dep.ver.servlet>
         <netflix.servo.ver>0.12.17</netflix.servo.ver>
         <micrometer.ver>0.12.0.RELEASE</micrometer.ver>
-        <fasterxml.jackson.version>2.9.1</fasterxml.jackson.version>
+<!--        <fasterxml.jackson.version>2.9.1</fasterxml.jackson.version>-->
         <spring-boot-starter-web.version>2.0.7.RELEASE</spring-boot-starter-web.version>
         <assertj-core.version>3.11.1</assertj-core.version>
         <metrics-aspectj.version>1.1.0</metrics-aspectj.version>

persistence-modules/hibernate-enterprise/README.md

@@ -9,4 +9,5 @@ This module contains articles about enterprise concerns such as Multitenancy, Er
 - [Hibernate Aggregate Functions](https://www.baeldung.com/hibernate-aggregate-functions)
 - [Common Hibernate Exceptions](https://www.baeldung.com/hibernate-exceptions)
 - [Hibernate Error “Not all named parameters have been set”](https://www.baeldung.com/hibernate-error-named-parameters-not-set)
-- [Various Logging Levels in Hibernate](https://www.baeldung.com/hibernate-logging-levels)
+- [Various Logging Levels in Hibernate](https://www.baeldung.com/hibernate-logging-levels)
+- [Hibernate: save, persist, update, merge, saveOrUpdate](https://www.baeldung.com/hibernate-save-persist-update-merge-saveorupdate)

persistence-modules/hibernate-enterprise/pom.xml

@@ -61,13 +61,25 @@
             <version>${byte-buddy.version}</version>
             <scope>test</scope>
         </dependency>
+        <dependency>
+            <groupId>org.hsqldb</groupId>
+            <artifactId>hsqldb</artifactId>
+            <version>${hsqldb.version}</version>
+            <scope>test</scope>
+        </dependency>
     </dependencies>
 
     <repositories>
         <repository>
-            <id>geodb-repo</id>
-            <name>GeoDB repository</name>
-            <url>http://repo.boundlessgeo.com/main/</url>
+            <id>osgeo</id>
+            <name>OSGeo Release Repository</name>
+            <url>https://repo.osgeo.org/repository/release/</url>
+            <snapshots>
+                <enabled>false</enabled>
+            </snapshots>
+            <releases>
+                <enabled>true</enabled>
+            </releases>
         </repository>
     </repositories>
 
@@ -77,6 +89,7 @@
         <mariaDB4j.version>2.2.3</mariaDB4j.version>
         <assertj-core.version>3.8.0</assertj-core.version>
         <geodb.version>0.9</geodb.version>
+        <hsqldb.version>2.3.4</hsqldb.version>
     </properties>
 
 </project>

persistence-modules/hibernate-enterprise/src/test/java/com/baeldung/persistence/save/SaveMethodsIntegrationTest.java

@@ -1,6 +1,14 @@
 package com.baeldung.persistence.save;
 
-import com.baeldung.persistence.model.Person;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotEquals;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertNotSame;
+import static org.junit.Assert.assertNull;
+import static org.junit.Assert.assertSame;
+
+import javax.persistence.PersistenceException;
+
 import org.hibernate.HibernateException;
 import org.hibernate.Session;
 import org.hibernate.SessionFactory;
@@ -8,9 +16,13 @@ import org.hibernate.boot.registry.StandardServiceRegistryBuilder;
 import org.hibernate.cfg.Configuration;
 import org.hibernate.dialect.HSQLDialect;
 import org.hibernate.service.ServiceRegistry;
-import org.junit.*;
+import org.junit.After;
+import org.junit.AfterClass;
+import org.junit.Before;
+import org.junit.BeforeClass;
+import org.junit.Test;
 
-import static org.junit.Assert.*;
+import com.baeldung.persistence.model.Person;
 
 /**
  * Testing specific implementation details for different methods:
@@ -21,12 +33,19 @@ public class SaveMethodsIntegrationTest {
     private static SessionFactory sessionFactory;
 
     private Session session;
+    private boolean doNotCommit = false;
 
     @BeforeClass
     public static void beforeTests() {
-        Configuration configuration = new Configuration().addAnnotatedClass(Person.class).setProperty("hibernate.dialect", HSQLDialect.class.getName()).setProperty("hibernate.connection.driver_class", org.hsqldb.jdbcDriver.class.getName())
-                .setProperty("hibernate.connection.url", "jdbc:hsqldb:mem:test").setProperty("hibernate.connection.username", "sa").setProperty("hibernate.connection.password", "").setProperty("hibernate.hbm2ddl.auto", "update");
-        ServiceRegistry serviceRegistry = new StandardServiceRegistryBuilder().applySettings(configuration.getProperties()).build();
+        Configuration configuration = new Configuration().addAnnotatedClass(Person.class)
+            .setProperty("hibernate.dialect", HSQLDialect.class.getName())
+            .setProperty("hibernate.connection.driver_class", org.hsqldb.jdbcDriver.class.getName())
+            .setProperty("hibernate.connection.url", "jdbc:hsqldb:mem:test")
+            .setProperty("hibernate.connection.username", "sa")
+            .setProperty("hibernate.connection.password", "")
+            .setProperty("hibernate.hbm2ddl.auto", "update");
+        ServiceRegistry serviceRegistry = new StandardServiceRegistryBuilder().applySettings(configuration.getProperties())
+            .build();
         sessionFactory = configuration.buildSessionFactory(serviceRegistry);
     }
 
@@ -34,6 +53,7 @@ public class SaveMethodsIntegrationTest {
     public void setUp() {
         session = sessionFactory.openSession();
         session.beginTransaction();
+        doNotCommit = false;
     }
 
     @Test
@@ -43,7 +63,8 @@ public class SaveMethodsIntegrationTest {
         person.setName("John");
         session.persist(person);
 
-        session.getTransaction().commit();
+        session.getTransaction()
+            .commit();
         session.close();
 
         session = sessionFactory.openSession();
@@ -68,15 +89,33 @@ public class SaveMethodsIntegrationTest {
         assertEquals(id1, id2);
     }
 
-    @Test(expected = HibernateException.class)
+    @Test(expected = PersistenceException.class)
     public void whenPersistDetached_thenThrowsException() {
 
+        doNotCommit = true;
+        
         Person person = new Person();
         person.setName("John");
         session.persist(person);
         session.evict(person);
-
+        
         session.persist(person);
+    }
+
+    @Test
+    public void whenMergeDetached_thenEntityUpdatedFromDatabase() {
+
+        Person person = new Person();
+        person.setName("John");
+        session.save(person);
+        session.flush();
+        session.evict(person);
+
+        person.setName("Mary");
+        Person mergedPerson = (Person) session.merge(person);
+
+        assertNotSame(person, mergedPerson);
+        assertEquals("Mary", mergedPerson.getName());
 
     }
 
@@ -92,7 +131,8 @@ public class SaveMethodsIntegrationTest {
 
         assertNotNull(id);
 
-        session.getTransaction().commit();
+        session.getTransaction()
+            .commit();
         session.close();
 
         assertEquals(id, person.getId());
@@ -128,22 +168,6 @@ public class SaveMethodsIntegrationTest {
 
     }
 
-    @Test
-    public void whenMergeDetached_thenEntityUpdatedFromDatabase() {
-
-        Person person = new Person();
-        person.setName("John");
-        session.save(person);
-        session.evict(person);
-
-        person.setName("Mary");
-        Person mergedPerson = (Person) session.merge(person);
-
-        assertNotSame(person, mergedPerson);
-        assertEquals("Mary", mergedPerson.getName());
-
-    }
-
     @Test
     public void whenMergeTransient_thenNewEntitySavedToDatabase() {
 
@@ -151,7 +175,8 @@ public class SaveMethodsIntegrationTest {
         person.setName("John");
         Person mergedPerson = (Person) session.merge(person);
 
-        session.getTransaction().commit();
+        session.getTransaction()
+            .commit();
         session.beginTransaction();
 
         assertNull(person.getId());
@@ -227,7 +252,8 @@ public class SaveMethodsIntegrationTest {
         person.setName("John");
         session.saveOrUpdate(person);
 
-        session.getTransaction().commit();
+        session.getTransaction()
+            .commit();
         session.close();
 
         session = sessionFactory.openSession();
@@ -250,7 +276,10 @@ public class SaveMethodsIntegrationTest {
 
     @After
     public void tearDown() {
-        session.getTransaction().commit();
+        if (!doNotCommit) {
+            session.getTransaction()
+                .commit();
+        }
         session.close();
     }
 

persistence-modules/hibernate-libraries/pom.xml

@@ -170,7 +170,6 @@
         <guava.version>29.0-jre</guava.version>
         <hibernate-types.version>2.9.7</hibernate-types.version>
         <hibernate.version>5.4.14.Final</hibernate.version>
-        <jackson.version>2.10.3</jackson.version>
         <javassist.version>3.27.0-GA</javassist.version>
         <jaxb.version>2.3.1</jaxb.version>
         <log4jdbc.version>2.0.0</log4jdbc.version>

persistence-modules/jooq/README.md

@@ -0,0 +1,3 @@
+### Relevant Articles:
+
+- [Getting Started with jOOQ](https://www.baeldung.com/jooq-intro)

persistence-modules/jooq/src/main/java/com/baeldung/jooq/Crud.java

@@ -19,14 +19,14 @@ public class Crud {
 
     public static Result<Record> getAll(DSLContext context, Table<? extends Record> table) {
         return context.select()
-                .from(table)
-                .fetch();
+          .from(table)
+          .fetch();
     }
 
     public static Result<Record> getFields(DSLContext context, Table<? extends Record> table, SelectFieldOrAsterisk... fields) {
         return context.select(fields)
-                .from(table)
-                .fetch();
+          .from(table)
+          .fetch();
     }
 
     public static <R extends Record> R getOne(DSLContext context, Table<R> table, Condition condition) {
@@ -35,9 +35,9 @@ public class Crud {
 
     public static <T> void update(DSLContext context, Table<? extends Record> table, Map<Field<T>, T> values, Condition condition) {
         context.update(table)
-                .set(values)
-                .where(condition)
-                .execute();
+          .set(values)
+          .where(condition)
+          .execute();
     }
 
     public static <R extends UpdatableRecord<R>> void update(UpdatableRecord<R> record) {
@@ -46,8 +46,8 @@ public class Crud {
 
     public static void delete(DSLContext context, Table<? extends Record> table, Condition condition) {
         context.delete(table)
-                .where(condition)
-                .execute();
+          .where(condition)
+          .execute();
     }
 
     public static <R extends UpdatableRecord<R>> void delete(UpdatableRecord<R> record) {

persistence-modules/jooq/src/main/java/com/baeldung/jooq/CrudExamples.java

@@ -60,8 +60,8 @@ public class CrudExamples {
 
     private void readValues(DSLContext context) {
         Result<Record> authors = getAll(
-                context,
-                Author.AUTHOR
+          context,
+          Author.AUTHOR
         );
 
         authors.forEach(author -> {
@@ -73,15 +73,15 @@ public class CrudExamples {
         });
 
         Result<Record> articles = getFields(
-                context,
-                Author.AUTHOR,
-                Article.ARTICLE.ID, Article.ARTICLE.TITLE
+          context,
+          Author.AUTHOR,
+          Article.ARTICLE.ID, Article.ARTICLE.TITLE
         );
 
         AuthorRecord author = getOne(
-                context,
-                Author.AUTHOR,
-                Author.AUTHOR.ID.eq(1)
+          context,
+          Author.AUTHOR,
+          Author.AUTHOR.ID.eq(1)
         );
     }
 
@@ -90,24 +90,22 @@ public class CrudExamples {
         fieldsToUpdate.put(Author.AUTHOR.FIRST_NAME, "David");
         fieldsToUpdate.put(Author.AUTHOR.LAST_NAME, "Brown");
         update(
-                context,
-                Author.AUTHOR,
-                fieldsToUpdate,
-                Author.AUTHOR.ID.eq(1)
+          context,
+          Author.AUTHOR,
+          fieldsToUpdate,
+          Author.AUTHOR.ID.eq(1)
         );
 
         ArticleRecord article = context.fetchOne(Article.ARTICLE, Article.ARTICLE.ID.eq(1));
         article.setTitle("A New Article Title");
-        update(
-                article
-        );
+        update(article);
     }
 
     private void deleteValues(DSLContext context) {
         delete(
-                context,
-                Article.ARTICLE,
-                Article.ARTICLE.ID.eq(1)
+          context,
+          Article.ARTICLE,
+          Article.ARTICLE.ID.eq(1)
         );
 
         AuthorRecord author = context.fetchOne(Author.AUTHOR, Author.AUTHOR.ID.eq(1));

persistence-modules/pom.xml

@@ -81,8 +81,7 @@
         <module>spring-data-redis</module>
         <module>spring-data-solr</module>
         <module>spring-hibernate-3</module>
-        <module>spring-hibernate-5</module> <!-- long running -->
-        <module>spring-hibernate4</module>
+        <module>spring-hibernate-5</module> <!-- long running -->        
         <module>spring-jpa</module>
         <module>spring-jpa-2</module>
         <module>spring-jdbc</module>

persistence-modules/spring-boot-persistence-2/src/main/java/com/baeldung/states/Application.java

@@ -0,0 +1,12 @@
+package com.baeldung.states;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class Application {
+    
+    public static void main(String[] args) {
+        SpringApplication.run(Application.class, args);
+    }
+}

persistence-modules/spring-boot-persistence-2/src/main/java/com/baeldung/states/UserEntity.java

@@ -0,0 +1,27 @@
+package com.baeldung.states;
+
+import lombok.AllArgsConstructor;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+import lombok.Setter;
+
+import javax.persistence.Entity;
+import javax.persistence.Id;
+import javax.persistence.ManyToOne;
+
+@Entity
+@AllArgsConstructor
+@NoArgsConstructor
+@Getter
+@Setter
+public class UserEntity {
+    @Id
+    private String name;
+
+    @ManyToOne
+    private UserEntity manager;
+
+    public UserEntity(String name) {
+        this.name = name;
+    }
+}

persistence-modules/spring-boot-persistence-2/src/main/java/com/baeldung/states/UserEntityWithCascade.java

@@ -0,0 +1,28 @@
+package com.baeldung.states;
+
+import lombok.AllArgsConstructor;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+import lombok.Setter;
+
+import javax.persistence.CascadeType;
+import javax.persistence.Entity;
+import javax.persistence.Id;
+import javax.persistence.ManyToOne;
+
+@Entity
+@AllArgsConstructor
+@NoArgsConstructor
+@Getter
+@Setter
+public class UserEntityWithCascade {
+    @Id
+    private String name;
+
+    @ManyToOne(cascade = CascadeType.PERSIST)
+    private UserEntityWithCascade manager;
+
+    public UserEntityWithCascade(String name) {
+        this.name = name;
+    }
+}

persistence-modules/spring-boot-persistence-2/src/test/java/com/baeldung/states/UserEntityIntegrationTest.java

@@ -0,0 +1,136 @@
+package com.baeldung.states;
+
+import org.hibernate.Session;
+import org.hibernate.SessionFactory;
+import org.hibernate.Transaction;
+import org.junit.jupiter.api.Test;
+import org.junit.runner.RunWith;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.test.context.junit4.SpringRunner;
+
+import javax.persistence.EntityManagerFactory;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+
+@RunWith(SpringRunner.class)
+@SpringBootTest
+class UserEntityIntegrationTest {
+    @Autowired
+    private EntityManagerFactory entityManagerFactory;
+
+    @Test
+    void givenName_thenShouldCreateDetachedUserEntity() {
+        // given
+        Session session = openSession();
+        UserEntity userEntity = new UserEntity("John");
+
+        // then
+        assertThat(session.contains(userEntity)).isFalse();
+        session.close();
+    }
+
+    @Test
+    void givenName_whenPersisted_thenShouldCreatePersistentUserEntity() {
+        // given
+        Session session = openSession();
+        UserEntity userEntity = new UserEntity("John");
+
+        // when
+        session.persist(userEntity);
+
+        // then
+        assertThat(session.contains(userEntity)).isTrue();
+        session.close();
+    }
+
+    @Test
+    void givenPersistentEntity_whenSessionClosed_thenShouldDetachEntity() {
+        // given
+        Session session = openSession();
+        UserEntity userEntity = new UserEntity("John");
+        session.persist(userEntity);
+        assertThat(session.contains(userEntity)).isTrue();
+
+        // when
+        session.close();
+
+        // then
+        assertThat(session.isOpen()).isFalse();
+        assertThatThrownBy(() -> session.contains(userEntity));
+    }
+
+    @Test
+    void givenPersistentEntity_whenAddedTransientManager_thenShouldThrowException() {
+        // given
+        Session session = openSession();
+        Transaction transaction = session.beginTransaction();
+        UserEntity userEntity = new UserEntity("John");
+        session.persist(userEntity);
+        UserEntity manager = new UserEntity("Adam");
+
+        // when
+        userEntity.setManager(manager);
+
+
+        // then
+        assertThatThrownBy(() -> {
+            session.saveOrUpdate(userEntity);
+            transaction.commit();
+        });
+        session.close();
+    }
+
+    @Test
+    void givenPersistentEntity_whenAddedPersistentManager_thenShouldSave() {
+        // given
+        Session session = openSession();
+        Transaction transaction = session.beginTransaction();
+        UserEntity userEntity = new UserEntity("John");
+        session.persist(userEntity);
+        UserEntity manager = new UserEntity("Adam");
+        session.persist(manager);
+
+        // when
+        userEntity.setManager(manager);
+
+
+        // then
+        session.saveOrUpdate(userEntity);
+        transaction.commit();
+        session.close();
+
+        Session otherSession = openSession();
+        UserEntity savedUser = otherSession.get(UserEntity.class, "John");
+        assertThat(savedUser.getManager().getName()).isEqualTo("Adam");
+    }
+
+    @Test
+    void givenPersistentEntityWithCascade_whenAddedTransientManager_thenShouldSave() {
+        // given
+        Session session = openSession();
+        Transaction transaction = session.beginTransaction();
+        UserEntityWithCascade userEntity = new UserEntityWithCascade("John");
+        session.persist(userEntity);
+        UserEntityWithCascade manager = new UserEntityWithCascade("Adam");
+
+        // when
+        userEntity.setManager(manager);
+
+
+        // then
+        session.saveOrUpdate(userEntity);
+        transaction.commit();
+        session.close();
+
+        Session otherSession = openSession();
+        UserEntityWithCascade savedUser = otherSession.get(UserEntityWithCascade.class, "John");
+        assertThat(savedUser.getManager().getName()).isEqualTo("Adam");
+    }
+
+
+    private Session openSession() {
+        return entityManagerFactory.unwrap(SessionFactory.class).openSession();
+    }
+}

persistence-modules/spring-boot-persistence-h2/README.md

@@ -1,5 +1,7 @@
 ### Relevant Articles: 
+
 - [Access the Same In-Memory H2 Database in Multiple Spring Boot Applications](https://www.baeldung.com/spring-boot-access-h2-database-multiple-apps)
 - [Spring Boot With H2 Database](https://www.baeldung.com/spring-boot-h2-database)
 - [Hibernate @NotNull vs @Column(nullable = false)](https://www.baeldung.com/hibernate-notnull-vs-nullable)
 - [Quick Guide to Hibernate enable_lazy_load_no_trans Property](https://www.baeldung.com/hibernate-lazy-loading-workaround)
+- [Where Does H2’s Embedded Database Store The Data?](https://www.baeldung.com/h2-embedded-db-data-storage)