Guide to JDO (#1730)

* Guide to JDO * Guide to JDO * Guide to JDO
2017-04-25 14:54:32 -04:00
parent 129c751cb4
commit b0e15fcca0
8 changed files with 323 additions and 21 deletions
@@ -0,0 +1,83 @@
+package com.baeldung.jdo;
+
+import java.util.Iterator;
+import java.util.List;
+import java.util.Random;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+import javax.jdo.JDOHelper;
+import javax.jdo.PersistenceManager;
+import javax.jdo.PersistenceManagerFactory;
+import javax.jdo.Query;
+import javax.jdo.Transaction;
+
+public class GuideToJDO {
+
+    private static final Logger LOGGER = Logger.getLogger(GuideToJDO.class.getName());
+    private Random rnd = new Random();
+
+    public static void main(String[] args) {
+        new GuideToJDO();
+    }
+
+    public GuideToJDO() {
+        CreateProducts();
+        ListProducts();
+    }
+
+    public void CreateProducts() {
+        PersistenceManagerFactory pmf = JDOHelper.getPersistenceManagerFactory("Tutorial");
+        PersistenceManager pm = pmf.getPersistenceManager();
+        Transaction tx = pm.currentTransaction();
+        try {
+            tx.begin();
+            Product product = new Product("Tablet", 80.0);
+            pm.makePersistent(product);
+            Product product2 = new Product("Phone", 20.0);
+            pm.makePersistent(product2);
+            Product product3 = new Product("Laptop", 200.0);
+            pm.makePersistent(product3);
+            for (int i = 0; i < 100; i++) {
+                String nam = "Product-" + i;
+                double price = rnd.nextDouble();
+                Product productx = new Product(nam, price);
+                pm.makePersistent(productx);
+            }
+            tx.commit();
+        } finally {
+            if (tx.isActive()) {
+                tx.rollback();
+            }
+            pm.close();
+        }
+
+    }
+
+    @SuppressWarnings("unchecked")
+    public void ListProducts() {
+        PersistenceManagerFactory pmf = JDOHelper.getPersistenceManagerFactory("Tutorial");
+        PersistenceManager pm = pmf.getPersistenceManager();
+        Transaction tx = pm.currentTransaction();
+        try {
+            tx.begin();
+
+            @SuppressWarnings("rawtypes")
+            Query q = pm.newQuery("SELECT FROM " + Product.class.getName() + " WHERE price < 1");
+            List<Product> products = (List<Product>) q.execute();
+            Iterator<Product> iter = products.iterator();
+            while (iter.hasNext()) {
+                Product p = iter.next();
+                LOGGER.log(Level.WARNING, "Product name: {0} - Price: {1}", new Object[] { p.name, p.price });
+            }
+
+            tx.commit();
+        } finally {
+            if (tx.isActive()) {
+                tx.rollback();
+            }
+
+            pm.close();
+        }
+    }
+}
@@ -0,0 +1,43 @@
+package com.baeldung.jdo;
+
+import javax.jdo.annotations.IdGeneratorStrategy;
+import javax.jdo.annotations.PersistenceCapable;
+import javax.jdo.annotations.Persistent;
+import javax.jdo.annotations.PrimaryKey;
+
+@PersistenceCapable
+public class Product {
+
+    @PrimaryKey
+    @Persistent(valueStrategy = IdGeneratorStrategy.INCREMENT)
+    long id;
+    String name = null;
+    Double price = 0.0;
+
+    public Product() {
+        this.name = null;
+        this.price = 0.0;
+    }
+
+    public Product(String name, Double price) {
+        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;
+    }
+
+}