DATAJPA-266 - Fixed SimpleJpaRepository.exists(…) for composite ids.

We now build a correct count query for entities that use a compound key mapped using @IdClass. Added integration tests for EclipseLink and OpenJPA to run the basic tests of SimpleJpaRepository against different persistence providers. Ignored failing test against OpenJPA.

src/main/java/org/springframework/data/jpa/repository/query/QueryUtils.java

@@ -58,10 +58,8 @@ import org.springframework.util.StringUtils;
 public abstract class QueryUtils {
 
 	public static final String COUNT_QUERY_STRING = "select count(%s) from %s x";
-	public static final String EXISTS_QUERY_STRING = "select count(%s) from %s x where x.%s = :id";
-
 	public static final String DELETE_ALL_QUERY_STRING = "delete from %s x";
-	public static final String READ_ALL_QUERY = "select x from %s x";
+
 	private static final String DEFAULT_ALIAS = "x";
 	private static final String COUNT_REPLACEMENT = "select count($3$5) $4$5$6";
 
@@ -74,6 +72,8 @@ public abstract class QueryUtils {
 	private static final String LEFT_JOIN = "left (outer )?join " + IDENTIFIER + " (as )?" + IDENTIFIER_GROUP;
 	private static final Pattern LEFT_JOIN_PATTERN = Pattern.compile(LEFT_JOIN, Pattern.CASE_INSENSITIVE);
 
+	private static final String EQUALS_CONDITION_STRING = "%s.%s = :%s";
+
 	private static final Set<PersistentAttributeType> ASSOCIATION_TYPES;
 
 	static {
@@ -113,6 +113,29 @@ public abstract class QueryUtils {
 
 	}
 
+	/**
+	 * Returns the query string to execute an exists query for the given id attributes.
+	 * 
+	 * @param entityName the name of the entity to create the query for, must not be {@literal null}.
+	 * @param countQueryPlaceHolder the placeholder for the count clause, must not be {@literal null}.
+	 * @param idAttributes the id attributes for the entity, must not be {@literal null}.
+	 * @return
+	 */
+	public static String getExistsQueryString(String entityName, String countQueryPlaceHolder,
+			Iterable<String> idAttributes) {
+
+		StringBuilder sb = new StringBuilder(String.format(COUNT_QUERY_STRING, countQueryPlaceHolder, entityName));
+		sb.append(" WHERE ");
+
+		for (String idAttribute : idAttributes) {
+			sb.append(String.format(EQUALS_CONDITION_STRING, "x", idAttribute, idAttribute));
+			sb.append(" AND ");
+		}
+
+		sb.append("1 = 1");
+		return sb.toString();
+	}
+
 	/**
 	 * Returns the query string for the given class name.
 	 * 

src/main/java/org/springframework/data/jpa/repository/support/JpaEntityInformation.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2011 the original author or authors.
+ * Copyright 2011-2013 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -25,6 +25,7 @@ import org.springframework.data.repository.core.EntityInformation;
  * Extension of {@link EntityInformation} to capture aditional JPA specific information about entities.
  * 
  * @author Oliver Gierke
+ * @author Thomas Darimont
  */
 public interface JpaEntityInformation<T, ID extends Serializable> extends EntityInformation<T, ID> {
 
@@ -35,6 +36,30 @@ public interface JpaEntityInformation<T, ID extends Serializable> extends Entity
 	 */
 	SingularAttribute<? super T, ?> getIdAttribute();
 
+	/**
+	 * Returns {@literal true} if the entity has a composite id
+	 * 
+	 * @return
+	 */
+	boolean hasCompositeId();
+
+	/**
+	 * Returns the attribute names of the id attributes. If the entity has a composite id, then all id attribute names are
+	 * returned. If the entity has a single id attribute then this single attribute name is returned.
+	 * 
+	 * @return
+	 */
+	Iterable<String> getIdAttributeNames();
+
+	/**
+	 * Extracts the value for the given id attribute from a composite id
+	 * 
+	 * @param id
+	 * @param idAttribute
+	 * @return
+	 */
+	Object getCompositeIdAttributeValue(Serializable id, String idAttribute);
+
 	/**
 	 * Returns the JPA entity name.
 	 * 

src/main/java/org/springframework/data/jpa/repository/support/JpaMetamodelEntityInformation.java

@@ -17,8 +17,10 @@ package org.springframework.data.jpa.repository.support;
 
 import java.io.Serializable;
 import java.lang.reflect.Field;
+import java.util.ArrayList;
 import java.util.Collections;
 import java.util.Iterator;
+import java.util.List;
 import java.util.Set;
 
 import javax.persistence.IdClass;
@@ -39,6 +41,7 @@ import org.springframework.util.ReflectionUtils;
  * to find the domain class' id field.
  * 
  * @author Oliver Gierke
+ * @author Thomas Darimont
  */
 public class JpaMetamodelEntityInformation<T, ID extends Serializable> extends JpaEntityInformationSupport<T, ID> {
 
@@ -118,6 +121,38 @@ public class JpaMetamodelEntityInformation<T, ID extends Serializable> extends J
 		return idMetadata.getSimpleIdAttribute();
 	}
 
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.data.jpa.repository.support.JpaEntityInformation#hasCompositeId()
+	 */
+	public boolean hasCompositeId() {
+		return !idMetadata.hasSimpleId();
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.data.jpa.repository.support.JpaEntityInformation#getIdAttributeNames()
+	 */
+	public Iterable<String> getIdAttributeNames() {
+
+		List<String> attributeNames = new ArrayList<String>(idMetadata.attributes.size());
+
+		for (SingularAttribute<? super T, ?> attribute : idMetadata.attributes) {
+			attributeNames.add(attribute.getName());
+		}
+
+		return attributeNames;
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.data.jpa.repository.support.JpaEntityInformation#getCompositeIdAttributeValue(java.io.Serializable, java.lang.String)
+	 */
+	public Object getCompositeIdAttributeValue(Serializable id, String idAttribute) {
+		Assert.isTrue(hasCompositeId());
+		return new DirectFieldAccessFallbackBeanWrapper(id).getPropertyValue(idAttribute);
+	}
+
 	/**
 	 * Simple value object to encapsulate id specific metadata.
 	 * 

src/main/java/org/springframework/data/jpa/repository/support/SimpleJpaRepository.java

@@ -50,6 +50,7 @@ import org.springframework.util.Assert;
  * 
  * @author Oliver Gierke
  * @author Eberhard Wolff
+ * @author Thomas Darimont
  * @param <T> the type of the entity to handle
  * @param <ID> the type of the entity's identifier
  */
@@ -219,13 +220,20 @@ public class SimpleJpaRepository<T, ID extends Serializable> implements JpaRepos
 
 			String placeholder = provider.getCountQueryPlaceholder();
 			String entityName = entityInformation.getEntityName();
-			String idAttributeName = entityInformation.getIdAttribute().getName();
-			String existsQuery = String.format(EXISTS_QUERY_STRING, placeholder, entityName, idAttributeName);
+			Iterable<String> idAttributeNames = entityInformation.getIdAttributeNames();
+			String existsQuery = QueryUtils.getExistsQueryString(entityName, placeholder, idAttributeNames);
 
 			TypedQuery<Long> query = em.createQuery(existsQuery, Long.class);
-			query.setParameter("id", id);
 
-			return query.getSingleResult() == 1;
+			if (entityInformation.hasCompositeId()) {
+				for (String idAttributeName : idAttributeNames) {
+					query.setParameter(idAttributeName, entityInformation.getCompositeIdAttributeValue(id, idAttributeName));
+				}
+			} else {
+				query.setParameter(idAttributeNames.iterator().next(), id);
+			}
+
+			return query.getSingleResult() == 1L;
 		} else {
 			return findOne(id) != null;
 		}

src/test/java/org/springframework/data/jpa/repository/support/EclipseLinkJpaRepositoryTests.java

@@ -0,0 +1,28 @@
+/*
+ * Copyright 2013 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.data.jpa.repository.support;
+
+import org.springframework.test.context.ContextConfiguration;
+
+/**
+ * Integration tests to execute {@link JpaRepositoryTests} against EclipseLink.
+ * 
+ * @author Oliver Gierke
+ */
+@ContextConfiguration("classpath:eclipselink.xml")
+public class EclipseLinkJpaRepositoryTests extends JpaRepositoryTests {
+
+}

src/test/java/org/springframework/data/jpa/repository/support/JpaEntityInformationSupportUnitTests.java

@@ -19,6 +19,7 @@ import static org.junit.Assert.*;
 import static org.mockito.Mockito.*;
 
 import java.io.Serializable;
+import java.util.Collections;
 
 import javax.persistence.Entity;
 import javax.persistence.EntityManager;
@@ -93,5 +94,17 @@ public class JpaEntityInformationSupportUnitTests {
 
 			return null;
 		}
+
+		public Iterable<String> getIdAttributeNames() {
+			return Collections.emptySet();
+		}
+
+		public boolean hasCompositeId() {
+			return false;
+		}
+
+		public Object getCompositeIdAttributeValue(Serializable id, String idAttribute) {
+			return null;
+		}
 	}
 }

src/test/java/org/springframework/data/jpa/repository/support/JpaRepositoryTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2008-2012 the original author or authors.
+ * Copyright 2008-2013 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -74,7 +74,7 @@ public class JpaRepositoryTests {
 	}
 
 	/**
-	 * DATAJPA-50
+	 * @see DATAJPA-50
 	 */
 	@Test
 	public void executesCrudOperationsForEntityWithIdClass() {
@@ -90,6 +90,20 @@ public class JpaRepositoryTests {
 		assertThat(idClassRepository.findOne(id), is(entity));
 	}
 
+	/**
+	 * @see DATAJPA-266
+	 */
+	@Test
+	public void testExistsForDomainObjectsWithCompositeKeys() throws Exception {
+
+		SampleWithIdClass s1 = idClassRepository.save(new SampleWithIdClass(1L, 1L));
+		SampleWithIdClass s2 = idClassRepository.save(new SampleWithIdClass(2L, 2L));
+
+		assertThat(idClassRepository.exists(s1.getId()), is(true));
+		assertThat(idClassRepository.exists(s2.getId()), is(true));
+		assertThat(idClassRepository.exists(new SampleWithIdClassPK(1L, 2L)), is(false));
+	}
+
 	private static interface SampleEntityRepository extends JpaRepository<SampleEntity, SampleEntityPK> {
 
 	}

src/test/java/org/springframework/data/jpa/repository/support/OpenJpaJpaRepositoryTests.java

@@ -0,0 +1,37 @@
+/*
+ * Copyright 2013 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.data.jpa.repository.support;
+
+import org.junit.Ignore;
+import org.springframework.test.context.ContextConfiguration;
+
+/**
+ * Integration tests to execute {@link JpaRepositoryTests} against OpenJpa.
+ * 
+ * @author Oliver Gierke
+ */
+@ContextConfiguration("classpath:openjpa.xml")
+public class OpenJpaJpaRepositoryTests extends JpaRepositoryTests {
+
+	/* 
+	 * (non-Javadoc)
+	 * @see org.springframework.data.jpa.repository.support.JpaRepositoryTests#testCrudOperationsForCompoundKeyEntity()
+	 */
+	@Override
+	@Ignore
+	public void testCrudOperationsForCompoundKeyEntity() throws Exception {
+	}
+}