DATAJPA-1058 - Better exception when named method parameter is required but missing.

The exception now is a IllegalStateException, and mentions @Param as well as the -parameters compiler flag.

Origina pull request: #208.

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

@@ -32,6 +32,8 @@ import org.springframework.util.Assert;
  */
 public class ParameterBinder {
 
+	static final String PARAMETER_NEEDS_TO_BE_NAMED = "For queries with named parameters you need to use provide names for method parameters. Use @Param for query method parameters, or when on Java 8+ use the javac flag -parameters.";
+
 	private final JpaParameters parameters;
 	private final Iterable<QueryParameterSetter> parameterSetters;
 

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

@@ -202,6 +202,8 @@ abstract class QueryParameterSetterFactory {
 		@Override
 		public QueryParameterSetter create(ParameterBinding binding, String queryString) {
 
+			Assert.notNull(binding, "Binding must not be null.");
+
 			JpaParameter parameter = QueryUtils.hasNamedParameter(queryString) //
 					? findParameterForBinding(binding) //
 					: parameters.getBindableParameter(binding.getPosition() - 1);
@@ -223,7 +225,7 @@ abstract class QueryParameterSetterFactory {
 		}
 
 		private static String getName(JpaParameter p) {
-			return p.getName().orElseThrow(() -> new IllegalArgumentException("Parameter needs to be named!"));
+			return p.getName().orElseThrow(() -> new IllegalStateException(ParameterBinder.PARAMETER_NEEDS_TO_BE_NAMED));
 		}
 	}
 

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

@@ -153,7 +153,7 @@ class StoredProcedureJpaQuery extends AbstractJpaQuery {
 
 			if (useNamedParameters) {
 				procedureQuery.registerStoredProcedureParameter(
-						param.getName().orElseThrow(() -> new IllegalArgumentException("Parameter needs to be named!")),
+						param.getName().orElseThrow(() -> new IllegalArgumentException(ParameterBinder.PARAMETER_NEEDS_TO_BE_NAMED)),
 						param.getType(), ParameterMode.IN);
 			} else {
 				procedureQuery.registerStoredProcedureParameter(param.getIndex() + 1, param.getType(), ParameterMode.IN);

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

@@ -0,0 +1,64 @@
+/*
+ * Copyright 2017 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.query;
+
+import static org.mockito.Mockito.*;
+
+import java.util.stream.Stream;
+
+import org.assertj.core.api.Assertions;
+import org.junit.Before;
+import org.junit.Test;
+import org.mockito.Mockito;
+import org.springframework.data.jpa.repository.query.JpaParameters.JpaParameter;
+import org.springframework.data.jpa.repository.query.StringQuery.ParameterBinding;
+
+/**
+ * @author Jens Schauder
+ */
+public class QueryParameterSetterFactoryTest {
+
+	JpaParameters parameters = mock(JpaParameters.class, Mockito.RETURNS_DEEP_STUBS);
+	ParameterBinding binding = mock(ParameterBinding.class);
+
+	QueryParameterSetterFactory setterFactory;
+
+	@Before
+	public void before() {
+
+		// we have one bindable parameter
+		when(parameters.getBindableParameters().stream()).thenReturn(Stream.of(mock(JpaParameter.class)));
+
+		setterFactory = QueryParameterSetterFactory.basic(parameters);
+	}
+
+	@Test // DATAJPA-1058
+	public void noExceptionWhenQueryDoesNotContainNamedParameters() {
+
+		setterFactory.create(binding, "QueryStringWithOutNamedParameter");
+	}
+
+	@Test // DATAJPA-1058
+	public void exceptionWhenQueryContainNamedParametersAndMethodParametersAreNotNamed() {
+
+		Assertions.assertThatExceptionOfType(IllegalStateException.class) //
+				.isThrownBy(() -> setterFactory.create(binding, "QueryStringWith :NamedParameter")) //
+				.withMessageContaining("Java 8") //
+				.withMessageContaining("@Param") //
+				.withMessageContaining("-parameters");
+	}
+
+}