Use singleton for EntityManagerFactory

4 files changed, 80 insertions, 23 deletions

diff --git a/src/beans/CategoryManager.java b/src/beans/CategoryManager.java
index fc3d438..db42f37 100644
--- a/src/beans/CategoryManager.java
+++ b/src/beans/CategoryManager.java
@@ -17,11 +17,10 @@ import javax.faces.bean.ManagedBean;
 import javax.faces.bean.SessionScoped;
 import javax.faces.context.FacesContext;
 import javax.persistence.EntityManager;
-import javax.persistence.EntityManagerFactory;
 import javax.persistence.EntityTransaction;
-import javax.persistence.Persistence;
 
 import jpa.Category;
+import jpa.EntityManagerFactorySingleton;
 
 @ManagedBean(name = "CategoryManager")
 @SessionScoped
@@ -41,10 +40,14 @@ public class CategoryManager
 
    public Collection getCategories()
    {
-      EntityManagerFactory factory = Persistence
-            .createEntityManagerFactory("catalog");
-      EntityManager manager = factory.createEntityManager();
-      return manager.createQuery("SELECT c FROM Category c ").getResultList();
+      EntityManager manager = EntityManagerFactorySingleton.getInstance()
+            .getEntityManagerFactory().createEntityManager();
+
+      Collection categories = manager.createQuery("SELECT c FROM Category c ")
+            .getResultList();
+      manager.close();
+
+      return categories;
    }
 
    public void select(javax.faces.event.ActionEvent actionEvent)
@@ -54,9 +57,8 @@ public class CategoryManager
       Integer selectedId = Integer.valueOf((String) params.get("selectedId"));
       // System.out.println(selectedId);
 
-      EntityManagerFactory factory = Persistence
-            .createEntityManagerFactory("catalog");
-      EntityManager manager = factory.createEntityManager();
+      EntityManager manager = EntityManagerFactorySingleton.getInstance()
+            .getEntityManagerFactory().createEntityManager();
 
       EntityTransaction tx = manager.getTransaction();
       tx.begin();
@@ -83,5 +85,6 @@ public class CategoryManager
          e.printStackTrace();
       }
       context.responseComplete();
+      manager.close();
    }
 }
diff --git a/src/beans/ProductManager.java b/src/beans/ProductManager.java
index d499e3c..3442c52 100644
--- a/src/beans/ProductManager.java
+++ b/src/beans/ProductManager.java
@@ -16,10 +16,9 @@ import javax.faces.bean.ManagedBean;
 import javax.faces.bean.SessionScoped;
 import javax.faces.context.FacesContext;
 import javax.persistence.EntityManager;
-import javax.persistence.EntityManagerFactory;
 import javax.persistence.EntityTransaction;
-import javax.persistence.Persistence;
 
+import jpa.EntityManagerFactorySingleton;
 import jpa.Product;
 
 @ManagedBean(name = "ProductManager")
@@ -37,12 +36,11 @@ public class ProductManager
    {
       FacesContext facesContext = FacesContext.getCurrentInstance();
       Map params = facesContext.getExternalContext().getRequestParameterMap();
-      String selectedId = (String) params.get("selectedId");
+      int selectedId = Integer.valueOf((String) params.get("selectedId"), 10);
       // System.out.println(selectedId);
 
-      EntityManagerFactory factory = Persistence
-            .createEntityManagerFactory("catalog");
-      EntityManager manager = factory.createEntityManager();
+      EntityManager manager = EntityManagerFactorySingleton.getInstance()
+            .getEntityManagerFactory().createEntityManager();
 
       EntityTransaction tx = manager.getTransaction();
       tx.begin();
@@ -69,6 +67,7 @@ public class ProductManager
          e.printStackTrace();
       }
       context.responseComplete();
+      manager.close();
    }
 
 }
diff --git a/src/beans/UserManager.java b/src/beans/UserManager.java
index 190926b..36fd807 100644
--- a/src/beans/UserManager.java
+++ b/src/beans/UserManager.java
@@ -16,11 +16,10 @@ import java.util.List;
 import javax.faces.bean.ManagedBean;
 import javax.faces.bean.SessionScoped;
 import javax.persistence.EntityManager;
-import javax.persistence.EntityManagerFactory;
 import javax.persistence.EntityTransaction;
-import javax.persistence.Persistence;
 import javax.persistence.Query;
 
+import jpa.EntityManagerFactorySingleton;
 import jpa.User;
 
 @ManagedBean(name = "UserManager")
@@ -43,9 +42,8 @@ public class UserManager
             && current.getPassword() != null
             && current.getPassword().length() > 0)
       {
-         EntityManagerFactory factory = Persistence
-               .createEntityManagerFactory("catalog");
-         EntityManager manager = factory.createEntityManager();
+         EntityManager manager = EntityManagerFactorySingleton.getInstance()
+               .getEntityManagerFactory().createEntityManager();
          Query query = manager.createQuery(
                "SELECT u FROM User u where u.username = :username and u.password = :password");
          query.setParameter("username", current.getUsername());
@@ -58,6 +56,8 @@ public class UserManager
             current = (User) results.get(0);
             outcome = "success";
          }
+
+         manager.close();
       }
       // System.out.println(outcome);
       return outcome;
@@ -97,9 +97,8 @@ public class UserManager
 
    public User getCurrent()
    {
-      EntityManagerFactory factory = Persistence
-            .createEntityManagerFactory("catalog");
-      EntityManager manager = factory.createEntityManager();
+      EntityManager manager = EntityManagerFactorySingleton.getInstance()
+            .getEntityManagerFactory().createEntityManager();
 
       EntityTransaction tx = manager.getTransaction();
       tx.begin();
@@ -115,6 +114,8 @@ public class UserManager
          tx.rollback();
       }
 
+      manager.close();
+
       return current;
    }
 }
diff --git a/src/jpa/EntityManagerFactorySingleton.java b/src/jpa/EntityManagerFactorySingleton.java
new file mode 100644
index 0000000..dbd4873
--- /dev/null
+++ b/src/jpa/EntityManagerFactorySingleton.java
@@ -0,0 +1,54 @@
+/**
+ * 
+ */
+package jpa;
+
+import javax.annotation.PreDestroy;
+import javax.enterprise.context.ApplicationScoped;
+import javax.persistence.EntityManagerFactory;
+import javax.persistence.Persistence;
+
+/**
+ * A singleton for application wide {@link EntityManagerFactory}. Increases
+ * performance significant.
+ *
+ * @author Stefan Suhren
+ * @version 1.0
+ */
+@ApplicationScoped
+public class EntityManagerFactorySingleton
+{
+   private static final String DB_PU = "catalog";
+
+   private static final EntityManagerFactorySingleton singleton = new EntityManagerFactorySingleton();
+
+   private EntityManagerFactory emf;
+
+   private EntityManagerFactorySingleton()
+   {
+   }
+
+   public static EntityManagerFactorySingleton getInstance()
+   {
+      return singleton;
+   }
+
+   public EntityManagerFactory getEntityManagerFactory()
+   {
+      if (emf == null)
+      {
+         emf = Persistence.createEntityManagerFactory(DB_PU);
+      }
+      return emf;
+   }
+
+   @PreDestroy
+   public void closeEmf()
+   {
+      if (emf != null && emf.isOpen())
+      {
+         emf.close();
+      }
+      emf = null;
+   }
+}