uncomment classes in core-java (#1777)

* uncomment classes in core-java

* Add content to guide to JDO

core-java/src/test/java/com/baeldung/java8/comparator/Employee.java

@@ -1,6 +1,4 @@
 package com.baeldung.java8.comparator;
-/*    
-
 import lombok.AllArgsConstructor;
 import lombok.Data;
 import lombok.EqualsAndHashCode;
@@ -22,4 +20,3 @@ public class Employee implements Comparable<Employee>{
     }
     
 }
-*/

core-java/src/test/java/com/baeldung/java8/comparator/Java8ComparatorTest.java

@@ -1,5 +1,4 @@
 package com.baeldung.java8.comparator;
-/*
 import java.util.Arrays;
 import java.util.Comparator;
 
@@ -164,5 +163,3 @@ public class Java8ComparatorTest {
 
 
 }
-
-*/

libraries/myPersistence.xml

@@ -0,0 +1,26 @@
+<?xml version="1.0" encoding="UTF-8"?><root>
+    
+    
+    
+
+    
+    
+
+    
+    
+
+    
+    
+
+    
+    
+
+    
+    
+
+    
+    
+
+    
+    
+</root>

libraries/pom.xml

@@ -251,6 +251,11 @@
 		    <artifactId>h2</artifactId>
 		    <version>1.4.194</version>
 		</dependency>
+		<dependency>
+		    <groupId>org.datanucleus</groupId>
+		    <artifactId>datanucleus-xml</artifactId>
+		    <version>5.0.0-release</version>
+		</dependency>		
     </dependencies>
 
     <properties>

libraries/src/main/java/com/baeldung/jdo/GuideToJDO.java

@@ -20,22 +20,29 @@ public class GuideToJDO {
     private static final Logger LOGGER = Logger.getLogger(GuideToJDO.class.getName());
     private Random rnd = new Random();
     private PersistenceUnitMetaData pumd;
+    private PersistenceUnitMetaData pumdXML;
 
     public static void main(String[] args) {
         new GuideToJDO();
     }
 
     public GuideToJDO() {
-        CreateProperties();
+        CreateH2Properties();
+        CreateXMLProperties();
         CreateProducts();
         ListProducts();
+        QueryJDOQL();
+        QuerySQL();
+        QueryJPQL();
         UpdateProducts();
         ListProducts();
         DeleteProducts();
         ListProducts();
+        persistXML();
+        listXMLProducts();
     }
 
-    public void CreateProperties(){
+    public void CreateH2Properties(){
         
         pumd = new PersistenceUnitMetaData("dynamic-unit", "RESOURCE_LOCAL", null);
         pumd.addClassName("com.baeldung.jdo.Product");
@@ -48,6 +55,14 @@ public class GuideToJDO {
         
     }
     
+    public void CreateXMLProperties(){
+        pumdXML = new PersistenceUnitMetaData("dynamic-unit", "RESOURCE_LOCAL", null);
+        pumdXML.addClassName("com.baeldung.jdo.ProductXML");
+        pumdXML.setExcludeUnlistedClasses();
+        pumdXML.addProperty("javax.jdo.option.ConnectionURL", "xml:file:myPersistence.xml");
+        pumdXML.addProperty("datanucleus.autoCreateSchema", "true");        
+    }
+    
     public void CreateProducts() {
         PersistenceManagerFactory pmf = new JDOPersistenceManagerFactory(pumd, null);
         PersistenceManager pm = pmf.getPersistenceManager();
@@ -140,4 +155,145 @@ public class GuideToJDO {
             pm.close();
         }
     }
+    
+    @SuppressWarnings({ "rawtypes", "unchecked" })
+    public void QueryJDOQL (){
+        PersistenceManagerFactory pmf = new JDOPersistenceManagerFactory(pumd, null);
+        PersistenceManager pm = pmf.getPersistenceManager();
+        Transaction tx = pm.currentTransaction();
+        try {
+            tx.begin();
+
+            // Declarative JDOQL :
+            LOGGER.log(Level.INFO, "Declarative JDOQL --------------------------------------------------------------");
+            Query qDJDOQL = pm.newQuery(Product.class);
+            qDJDOQL.setFilter("name == 'Tablet' && price == price_value");
+            qDJDOQL.declareParameters("double price_value");
+            List<Product> resultsqDJDOQL = qDJDOQL.setParameters(80.0).executeList();
+
+            Iterator<Product> iterDJDOQL = resultsqDJDOQL.iterator();
+            while (iterDJDOQL.hasNext()) {
+                Product p = iterDJDOQL.next();
+                LOGGER.log(Level.WARNING, "Product name: {0} - Price: {1}", new Object[] { p.name, p.price });
+            }
+            LOGGER.log(Level.INFO, "--------------------------------------------------------------");
+            
+            tx.commit();
+        } finally {
+            if (tx.isActive()) {
+                tx.rollback();
+            }
+
+            pm.close();
+        }
+    }
+    
+    @SuppressWarnings({ "rawtypes", "unchecked" })
+    public void QuerySQL (){
+        PersistenceManagerFactory pmf = new JDOPersistenceManagerFactory(pumd, null);
+        PersistenceManager pm = pmf.getPersistenceManager();
+        Transaction tx = pm.currentTransaction();
+        try {
+            tx.begin();
+
+            //SQL :
+            LOGGER.log(Level.INFO, "SQL --------------------------------------------------------------");
+            Query query = pm.newQuery("javax.jdo.query.SQL", "SELECT * FROM PRODUCT");
+            query.setClass(Product.class);
+            List<Product> results = query.executeList();
+            
+            Iterator<Product> iter = results.iterator();
+            while (iter.hasNext()) {
+                Product p = iter.next();
+                LOGGER.log(Level.WARNING, "Product name: {0} - Price: {1}", new Object[] { p.name, p.price });
+            }
+            LOGGER.log(Level.INFO, "--------------------------------------------------------------");
+            
+            tx.commit();
+        } finally {
+            if (tx.isActive()) {
+                tx.rollback();
+            }
+
+            pm.close();
+        }
+    }
+    
+    @SuppressWarnings({ "rawtypes", "unchecked" })
+    public void QueryJPQL (){
+        PersistenceManagerFactory pmf = new JDOPersistenceManagerFactory(pumd, null);
+        PersistenceManager pm = pmf.getPersistenceManager();
+        Transaction tx = pm.currentTransaction();
+        try {
+            tx.begin();
+
+            //JPQL :
+            LOGGER.log(Level.INFO, "JPQL --------------------------------------------------------------");
+            Query q = pm.newQuery("JPQL", "SELECT p FROM "+Product.class.getName()+" p WHERE p.name = 'Laptop'");
+            List results = (List)q.execute();
+            
+            Iterator<Product> iter = results.iterator();
+            while (iter.hasNext()) {
+                Product p = iter.next();
+                LOGGER.log(Level.WARNING, "Product name: {0} - Price: {1}", new Object[] { p.name, p.price });
+            }
+            LOGGER.log(Level.INFO, "--------------------------------------------------------------");
+            
+            tx.commit();
+        } finally {
+            if (tx.isActive()) {
+                tx.rollback();
+            }
+
+            pm.close();
+        }
+    }
+    
+    public void persistXML(){
+        PersistenceManagerFactory pmf = new JDOPersistenceManagerFactory(pumdXML, null);
+        PersistenceManager pm = pmf.getPersistenceManager();
+        Transaction tx = pm.currentTransaction();
+        try {
+            tx.begin();
+            ProductXML productXML = new ProductXML(0,"Tablet", 80.0);
+            pm.makePersistent(productXML);
+            ProductXML productXML2 = new ProductXML(1,"Phone", 20.0);
+            pm.makePersistent(productXML2);
+            ProductXML productXML3 = new ProductXML(2,"Laptop", 200.0);
+            pm.makePersistent(productXML3);
+            tx.commit();
+        } finally {
+            if (tx.isActive()) {
+                tx.rollback();
+            }
+            pm.close();
+        }
+    }
+    
+    @SuppressWarnings({ "rawtypes", "unchecked" })
+    public void listXMLProducts(){
+        PersistenceManagerFactory pmf = new JDOPersistenceManagerFactory(pumdXML, null);
+        PersistenceManager pm = pmf.getPersistenceManager();
+        Transaction tx = pm.currentTransaction();
+        try {
+            tx.begin();
+
+            Query q = pm.newQuery("SELECT FROM " + ProductXML.class.getName());
+            List<ProductXML> products = (List<ProductXML>) q.execute();
+            Iterator<ProductXML> iter = products.iterator();
+            while (iter.hasNext()) {
+                ProductXML p = iter.next();
+                LOGGER.log(Level.WARNING, "Product name: {0} - Price: {1}", new Object[] { p.getName(), p.getPrice() });
+                pm.deletePersistent(p);
+            }
+            LOGGER.log(Level.INFO, "--------------------------------------------------------------");
+            tx.commit();
+        } finally {
+            if (tx.isActive()) {
+                tx.rollback();
+            }
+
+            pm.close();
+        }
+    }
 }

libraries/src/main/java/com/baeldung/jdo/ProductXML.java

@@ -0,0 +1,44 @@
+package com.baeldung.jdo;
+
+import javax.jdo.annotations.PersistenceCapable;
+import javax.jdo.annotations.PrimaryKey;
+import javax.xml.bind.annotation.XmlAttribute;
+
+@PersistenceCapable()
+public class ProductXML {
+
+    @XmlAttribute
+    private long productNumber = 0;
+    @PrimaryKey
+    private String name = null;
+    private Double price = 0.0;
+
+    public ProductXML() {
+        this.productNumber = 0;
+        this.name = null;
+        this.price = 0.0;
+    }
+
+    public ProductXML(long productNumber, String name, Double price) {
+        this.productNumber = productNumber;
+        this.name = name;
+        this.price = price;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    public Double getPrice() {
+        return price;
+    }
+
+    public void setPrice(Double price) {
+        this.price = price;
+    }
+
+}