DATAJPA-121 - Corrected query handling if null parameters are provided.

If a query is executed and null values are provided we now recreate a query with an IS NULL predicate correctly.

src/test/java/org/springframework/data/jpa/repository/query/ParameterExpressionProviderTests.java

@@ -12,13 +12,14 @@ import javax.persistence.criteria.ParameterExpression;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.springframework.data.jpa.domain.sample.User;
-import org.springframework.data.jpa.repository.query.JpaQueryCreator.ParameterExpressionProvider;
 import org.springframework.data.repository.query.Parameters;
+import org.springframework.data.repository.query.ParametersParameterAccessor;
+import org.springframework.data.repository.query.parser.Part;
 import org.springframework.test.context.ContextConfiguration;
 import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
 
 /**
- * Integration tests for {@link ParameterExpressionProvider}.
+ * Integration tests for {@link ParameterMetadataProvider}.
  * 
  * @author Oliver Gierke
  */
@@ -38,9 +39,11 @@ public class ParameterExpressionProviderTests {
 
 		Method method = SampleRepository.class.getMethod("findByIdGreaterThan", int.class);
 		Parameters parameters = new Parameters(method);
+		ParametersParameterAccessor accessor = new ParametersParameterAccessor(parameters, new Object[] { 1 });
+		Part part = new Part("IdGreaterThan", User.class);
 
-		ParameterExpressionProvider provider = new ParameterExpressionProvider(em.getCriteriaBuilder(), parameters);
-		ParameterExpression<? extends Comparable> expression = provider.next(Comparable.class);
+		ParameterMetadataProvider provider = new ParameterMetadataProvider(em.getCriteriaBuilder(), accessor);
+		ParameterExpression<? extends Comparable> expression = provider.next(part, Comparable.class).getExpression();
 		assertThat(expression.getParameterType(), is(typeCompatibleWith(int.class)));
 	}
 

src/test/java/org/springframework/data/jpa/repository/query/PartTreeJpaQueryIntegrationTests.java

@@ -1,7 +1,9 @@
 /*
- * Copyright 2011 the original author or authors.
+ * Copyright 2011-2012 the original author or authors.
  *
- * Licensed under the Apache License, Version 2.0 (the "License");
+ * Licensed under the Apache License, Version 2.0 (the "License
+import org.springframework.aop.framework.Advised;
+");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
@@ -15,11 +17,19 @@
  */
 package org.springframework.data.jpa.repository.query;
 
+import static org.hamcrest.Matchers.*;
+import static org.junit.Assert.*;
+import static org.springframework.test.util.ReflectionTestUtils.*;
+
 import java.lang.reflect.Method;
+import java.util.Arrays;
+import java.util.Iterator;
 
 import javax.persistence.EntityManager;
 import javax.persistence.PersistenceContext;
+import javax.persistence.Query;
 
+import org.hibernate.ejb.HibernateQuery;
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.rules.ExpectedException;
@@ -79,6 +89,28 @@ public class PartTreeJpaQueryIntegrationTests {
 		testIgnoreCase("findByIdAllIgnoringCase", 3);
 	}
 
+	/**
+	 * @see DATAJPA-121
+	 */
+	@Test
+	public void recreatesQueryIfNullValueIsGiven() throws Exception {
+
+		Method method = UserRepository.class.getMethod("findByFirstname", String.class, Pageable.class);
+		JpaQueryMethod queryMethod = new JpaQueryMethod(method, new DefaultRepositoryMetadata(UserRepository.class),
+				PersistenceProvider.fromEntityManager(entityManager));
+		PartTreeJpaQuery jpaQuery = new PartTreeJpaQuery(queryMethod, entityManager);
+
+		Query query = jpaQuery.createQuery(new Object[] { "Matthews", new PageRequest(0, 1) });
+
+		HibernateQuery hibernateQuery = getValue(query, "h.target.val$jpaqlQuery");
+		assertThat(hibernateQuery.getHibernateQuery().getQueryString(), endsWith("firstname=:param0"));
+
+		query = jpaQuery.createQuery(new Object[] { null, new PageRequest(0, 1) });
+
+		hibernateQuery = getValue(query, "h.target.val$jpaqlQuery");
+		assertThat(hibernateQuery.getHibernateQuery().getQueryString(), endsWith("firstname is null"));
+	}
+
 	private void testIgnoreCase(String methodName, Object... values) throws Exception {
 
 		Class<?>[] parameterTypes = new Class[values.length];
@@ -92,6 +124,19 @@ public class PartTreeJpaQueryIntegrationTests {
 		jpaQuery.createQuery(values);
 	}
 
+	@SuppressWarnings("unchecked")
+	private static <T> T getValue(Object source, String path) {
+
+		Iterator<String> split = Arrays.asList(path.split("\\.")).iterator();
+		Object result = source;
+
+		while (split.hasNext()) {
+			result = getField(result, split.next());
+		}
+
+		return (T) result;
+	}
+
 	interface UserRepository extends Repository<User, Long> {
 
 		Page<User> findByFirstname(String firstname, Pageable pageable);