--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/buildframework/helium/sf/java/metadata/src/com/nokia/helium/metadata/JpaDAO.java	Fri Aug 13 14:59:05 2010 +0300
@@ -0,0 +1,100 @@
+/*
+ * Copyright (c) 2007-2008 Nokia Corporation and/or its subsidiary(-ies).
+ * All rights reserved.
+ * This component and the accompanying materials are made available
+ * under the terms of the License "Eclipse Public License v1.0"
+ * which accompanies this distribution, and is available
+ * at the URL "http://www.eclipse.org/legal/epl-v10.html".
+ *
+ * Initial Contributors:
+ * Nokia Corporation - initial contribution.
+ *
+ * Contributors:
+ *
+ * Description:  
+ *
+ */
+package com.nokia.helium.metadata;
+
+import java.io.Serializable;
+import java.lang.reflect.ParameterizedType;
+import java.util.List;
+
+import javax.persistence.EntityManager;
+import javax.persistence.PersistenceContext;
+
+/**
+ * Abstract class which implement the DAO pattern for the JPA
+ * API. 
+ *
+ * @param <T> implementing the DAO for T.
+ */
+public abstract class JpaDAO<T> implements DAO<T> {
+    
+    private Class<T> entityBeanType;
+   
+    @PersistenceContext
+    private EntityManager entityManager;
+
+    /**
+     * Default constructor. Does some basic internal configuration.
+     */
+    @SuppressWarnings("unchecked")
+    public JpaDAO() {
+        this.entityBeanType = (Class<T>) ((ParameterizedType) getClass()
+                .getGenericSuperclass()).getActualTypeArguments()[0];
+    }
+    
+    /**
+     * @param entityManager the entityManager to set
+     */
+    public void setEntityManager(EntityManager entityManager) {
+        this.entityManager = entityManager;
+    }
+
+    /**
+     * @return the entityManager
+     */
+    protected EntityManager getEntityManager() {
+        return entityManager;
+    }
+    
+    /**
+     * {@inheritDoc}
+     */
+    public T findById(Serializable id) {
+        return entityManager.find(getEntityBeanType(), id);
+    }
+   
+    /**
+     * {@inheritDoc}
+     */
+    public List<T> findAll() {
+        return entityManager.createQuery("from " +
+                getEntityBeanType().getName(), getEntityBeanType()).getResultList();
+    }
+   
+    /**
+     * Get the class this object is implementing the DAO for.  
+     * @return the class this object is implementing the DAO for.
+     */
+    protected Class<T> getEntityBeanType() {
+        return entityBeanType;
+    }
+    
+    /**
+     * {@inheritDoc}
+     */
+    public void persist(T data) {
+        entityManager.persist(data);
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public void remove(T data) {
+        entityManager.remove(data);
+    }
+   
+}
+   
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