DATAJPA-954 - Delete by Predicate feature

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

@@ -0,0 +1,43 @@
+package org.springframework.data.jpa.repository.support;
+
+import com.querydsl.core.types.EntityPath;
+import com.querydsl.jpa.EclipseLinkTemplates;
+import com.querydsl.jpa.HQLTemplates;
+import com.querydsl.jpa.OpenJPATemplates;
+import com.querydsl.jpa.impl.JPADeleteClause;
+import org.springframework.data.jpa.provider.PersistenceProvider;
+
+import javax.persistence.EntityManager;
+
+/**
+ * Helper instance to ease access to DeleteClause JPA query API.
+ *
+ * @author Nikita Mishchenko
+ */
+public class DeleteQuerydsl {
+
+    private final EntityManager em;
+    private final PersistenceProvider provider;
+    private final EntityPath<?> path;
+
+    public DeleteQuerydsl(EntityManager em, EntityPath<?> path) {
+        this.em = em;
+        this.provider = PersistenceProvider.fromEntityManager(em);
+        this.path = path;
+    }
+
+    public JPADeleteClause createQuery() {
+        switch (provider) {
+            case ECLIPSELINK:
+                return new JPADeleteClause(em, path, EclipseLinkTemplates.DEFAULT);
+            case HIBERNATE:
+                return new JPADeleteClause(em, path, HQLTemplates.DEFAULT);
+            case OPEN_JPA:
+                return new JPADeleteClause(em, path, OpenJPATemplates.DEFAULT);
+            case GENERIC_JPA:
+            default:
+                return new JPADeleteClause(em, path);
+        }
+    }
+
+}

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

@@ -28,6 +28,7 @@
 import org.springframework.data.querydsl.EntityPathResolver;
 import org.springframework.data.querydsl.QSort;
 import org.springframework.data.querydsl.QueryDslPredicateExecutor;
+import org.springframework.data.querydsl.QueryDslPredicateModifyingExecutor;
 import org.springframework.data.querydsl.SimpleEntityPathResolver;
 import org.springframework.data.repository.support.PageableExecutionUtils;
 import org.springframework.data.repository.support.PageableExecutionUtils.TotalSupplier;
@@ -38,29 +39,32 @@
 import com.querydsl.core.types.dsl.PathBuilder;
 import com.querydsl.jpa.JPQLQuery;
 import com.querydsl.jpa.impl.AbstractJPAQuery;
+import com.querydsl.jpa.impl.JPADeleteClause;
+import org.springframework.transaction.annotation.Transactional;
 
 /**
  * QueryDsl specific extension of {@link SimpleJpaRepository} which adds implementation for
  * {@link QueryDslPredicateExecutor}.
- * 
+ *
  * @author Oliver Gierke
  * @author Thomas Darimont
  * @author Mark Paluch
  * @author Jocelyn Ntakpe
  */
 public class QueryDslJpaRepository<T, ID extends Serializable> extends SimpleJpaRepository<T, ID>
-		implements QueryDslPredicateExecutor<T> {
+		implements QueryDslPredicateExecutor<T>, QueryDslPredicateModifyingExecutor {
 
 	private static final EntityPathResolver DEFAULT_ENTITY_PATH_RESOLVER = SimpleEntityPathResolver.INSTANCE;
 
 	private final EntityPath<T> path;
 	private final PathBuilder<T> builder;
 	private final Querydsl querydsl;
+    private final DeleteQuerydsl deleteQuerydsl;
 
 	/**
 	 * Creates a new {@link QueryDslJpaRepository} from the given domain class and {@link EntityManager}. This will use
 	 * the {@link SimpleEntityPathResolver} to translate the given domain class into an {@link EntityPath}.
-	 * 
+	 *
 	 * @param entityInformation must not be {@literal null}.
 	 * @param entityManager must not be {@literal null}.
 	 */
@@ -71,7 +75,7 @@ public QueryDslJpaRepository(JpaEntityInformation<T, ID> entityInformation, Enti
 	/**
 	 * Creates a new {@link QueryDslJpaRepository} from the given domain class and {@link EntityManager} and uses the
 	 * given {@link EntityPathResolver} to translate the domain class into an {@link EntityPath}.
-	 * 
+	 *
 	 * @param entityInformation must not be {@literal null}.
 	 * @param entityManager must not be {@literal null}.
 	 * @param resolver must not be {@literal null}.
@@ -84,6 +88,7 @@ public QueryDslJpaRepository(JpaEntityInformation<T, ID> entityInformation, Enti
 		this.path = resolver.createPath(entityInformation.getJavaType());
 		this.builder = new PathBuilder<T>(path.getType(), path.getMetadata());
 		this.querydsl = new Querydsl(entityManager, builder);
+        this.deleteQuerydsl = new DeleteQuerydsl(entityManager, path);
 	}
 
 	/*
@@ -113,7 +118,7 @@ public List<T> findAll(Predicate predicate, OrderSpecifier<?>... orders) {
 		return executeSorted(createQuery(predicate).select(path), orders);
 	}
 
-	/* 
+	/*
 	 * (non-Javadoc)
 	 * @see org.springframework.data.querydsl.QueryDslPredicateExecutor#findAll(com.mysema.query.types.Predicate, org.springframework.data.domain.Sort)
 	 */
@@ -122,7 +127,7 @@ public List<T> findAll(Predicate predicate, Sort sort) {
 		return executeSorted(createQuery(predicate).select(path), sort);
 	}
 
-	/* 
+	/*
 	 * (non-Javadoc)
 	 * @see org.springframework.data.querydsl.QueryDslPredicateExecutor#findAll(com.mysema.query.types.OrderSpecifier[])
 	 */
@@ -150,6 +155,16 @@ public long get() {
 		});
 	}
 
+    /*
+     * (non-Javadoc)
+     * @see org.springframework.data.querydsl.QueryDslPredicateModifyingExecutor#delete(com.mysema.query.types.Predicate)
+     */
+    @Transactional
+    @Override
+    public long delete(Predicate... predicate) {
+        return createDeleteClause(predicate).execute();
+    }
+
 	/*
 	 * (non-Javadoc)
 	 * @see org.springframework.data.querydsl.QueryDslPredicateExecutor#count(com.mysema.query.types.Predicate)
@@ -159,7 +174,7 @@ public long count(Predicate predicate) {
 		return createQuery(predicate).fetchCount();
 	}
 
-	/* 
+	/*
 	 * (non-Javadoc)
 	 * @see org.springframework.data.querydsl.QueryDslPredicateExecutor#exists(com.mysema.query.types.Predicate)
 	 */
@@ -170,7 +185,7 @@ public boolean exists(Predicate predicate) {
 
 	/**
 	 * Creates a new {@link JPQLQuery} for the given {@link Predicate}.
-	 * 
+	 *
 	 * @param predicate
 	 * @return the Querydsl {@link JPQLQuery}.
 	 */
@@ -193,7 +208,29 @@ protected JPQLQuery<?> createQuery(Predicate... predicate) {
 		return query;
 	}
 
-	/**
+    /**
+     * Creates a new {@link JPADeleteClause} for the given {@link Predicate}.
+     *
+     * @param predicate
+     * @return the Querydsl {@link JPADeleteClause}.
+     */
+    protected JPADeleteClause createDeleteClause(Predicate... predicate) {
+        JPADeleteClause deleteClause = deleteQuerydsl.createQuery().where(predicate);
+        CrudMethodMetadata metadata = getRepositoryMethodMetadata();
+
+        if (metadata == null) {
+            return deleteClause;
+        }
+
+        LockModeType type = metadata.getLockModeType();
+        deleteClause = type == null ? deleteClause : deleteClause.setLockMode(type);
+
+
+        return deleteClause;
+    }
+
+
+    /**
 	 * Creates a new {@link JPQLQuery} count query for the given {@link Predicate}.
 	 *
 	 * @param predicate, can be {@literal null}.
@@ -205,7 +242,7 @@ protected JPQLQuery<?> createCountQuery(Predicate predicate) {
 
 	/**
 	 * Executes the given {@link JPQLQuery} after applying the given {@link OrderSpecifier}s.
-	 * 
+	 *
 	 * @param query must not be {@literal null}.
 	 * @param orders must not be {@literal null}.
 	 * @return
@@ -216,7 +253,7 @@ private List<T> executeSorted(JPQLQuery<T> query, OrderSpecifier<?>... orders) {
 
 	/**
 	 * Executes the given {@link JPQLQuery} after applying the given {@link Sort}.
-	 * 
+	 *
 	 * @param query must not be {@literal null}.
 	 * @param sort must not be {@literal null}.
 	 * @return

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

@@ -92,6 +92,23 @@ public void executesPredicatesCorrectly() throws Exception {
 		assertThat(result, hasItems(carter, dave));
 	}
 
+    @Test
+    public void executesDeletePredicatesCorrectly() throws Exception {
+
+        BooleanExpression isCalledDave = user.firstname.eq("Dave");
+        BooleanExpression isBeauford = user.lastname.eq("Beauford");
+
+        List<User> result = repository.findAll(isCalledDave.or(isBeauford));
+
+        assertThat(result.size(), is(2));
+
+        repository.delete(isCalledDave);
+
+        result = repository.findAll(isCalledDave.or(isBeauford));
+
+        assertThat(result.size(), is(1));
+    }
+
 	@Test
 	public void executesStringBasedPredicatesCorrectly() throws Exception {