From 2a620bf30ada3e5b09bb370d1a9fed02a78c53ea Mon Sep 17 00:00:00 2001
From: Sebastian Schmelzer
Date: Mon, 30 Jul 2012 19:20:05 +0200
Subject: Added abstract entity classes

---
 src/main/java/nu/xss/jpa/dao/GenericJpaDao.java | 54 +++++++++++++++++++++++--
 1 file changed, 50 insertions(+), 4 deletions(-)

(limited to 'src/main/java/nu/xss/jpa/dao/GenericJpaDao.java')

diff --git a/src/main/java/nu/xss/jpa/dao/GenericJpaDao.java b/src/main/java/nu/xss/jpa/dao/GenericJpaDao.java
index 9e2babb..21ee630 100644
--- a/src/main/java/nu/xss/jpa/dao/GenericJpaDao.java
+++ b/src/main/java/nu/xss/jpa/dao/GenericJpaDao.java
@@ -5,15 +5,20 @@ import java.lang.reflect.ParameterizedType;
 import java.util.List;
 
 import javax.persistence.EntityManager;
+import javax.persistence.NoResultException;
+import javax.persistence.NonUniqueResultException;
 import javax.persistence.PersistenceContext;
 import javax.persistence.criteria.CriteriaBuilder;
 import javax.persistence.criteria.CriteriaQuery;
 import javax.persistence.criteria.Root;
 
+import nu.xss.jpa.entity.TypedEntity;
+
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-public abstract class GenericJpaDao<E, K> implements Dao<E, K>, Serializable {
+public abstract class GenericJpaDao<E extends TypedEntity<K>, K> implements
+		Dao<E, K>, Serializable {
 
 	private static final long serialVersionUID = 4998055731089977476L;
 	protected final Logger logger = LoggerFactory.getLogger(this.getClass());
@@ -54,11 +59,52 @@ public abstract class GenericJpaDao<E, K> implements Dao<E, K>, Serializable {
 	}
 
 	public List<E> findAll() {
-		CriteriaBuilder cb = entityManager.getCriteriaBuilder();
-		CriteriaQuery<E> c = cb.createQuery(this.entity);
+		return find(createSimpleQuery());
+	}
+	
+	protected CriteriaBuilder getCriteriaBuilder() {
+		return entityManager.getCriteriaBuilder();
+	}
+
+	protected CriteriaQuery<E> createQuery() {
+		CriteriaQuery<E> c = getCriteriaBuilder().createQuery(this.entity);
+		return c;
+	}
+
+	protected CriteriaQuery<E> createSimpleQuery() {
+		CriteriaQuery<E> c = getCriteriaBuilder().createQuery(this.entity);
 		Root<E> root = c.from(this.entity);
 		c.select(root);
-		return entityManager.createQuery(c).getResultList();
+		return c;
 	}
 
+	protected List<E> find(CriteriaQuery<E> query) {
+		return entityManager.createQuery(query).getResultList();
+	}
+
+	protected E findSingle(CriteriaQuery<E> query) {
+		return entityManager.createQuery(query).getSingleResult();
+	}
+
+	protected E findSingleOrNull(CriteriaQuery<E> query) {
+		try {
+			return findSingle(query);
+		} catch (final NoResultException e) {
+			return null;
+		} catch (final NonUniqueResultException e) {
+			logger.error("Found more than one result.. return first one");
+			return null;
+		}
+	}
+
+	protected E findSingleFirstOrNull(CriteriaQuery<E> query) {
+		try {
+			return findSingle(query);
+		} catch (final NoResultException e) {
+			return null;
+		} catch (final NonUniqueResultException e) {
+			logger.warn("Found more than one result.. return first one");
+			return find(query).get(0);
+		}
+	}
 }
-- 
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