DATACMNS-987 Jackson converter gets only loaded iff jackson and jayway are present

pom.xml

@@ -5,7 +5,7 @@
 
 	<groupId>org.springframework.data</groupId>
 	<artifactId>spring-data-commons</artifactId>
-	<version>1.14.0.BUILD-SNAPSHOT</version>
+	<version>1.14.0.DATACMNS-987-SNAPSHOT</version>
 
 	<name>Spring Data Core</name>
 

src/main/java/org/springframework/data/web/config/SpringDataWebConfiguration.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2013-2016 the original author or authors.
+ * Copyright 2013-2017 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.
@@ -44,9 +44,10 @@
 /**
  * Configuration class to register {@link PageableHandlerMethodArgumentResolver},
  * {@link SortHandlerMethodArgumentResolver} and {@link DomainClassConverter}.
- * 
+ *
  * @since 1.6
  * @author Oliver Gierke
+ * @author Jens Schauder
  */
 @Configuration
 public class SpringDataWebConfiguration extends WebMvcConfigurerAdapter {
@@ -72,7 +73,7 @@ public SortHandlerMethodArgumentResolver sortResolver() {
 		return new SortHandlerMethodArgumentResolver();
 	}
 
-	/* 
+	/*
 	 * (non-Javadoc)
 	 * @see org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter#addFormatters(org.springframework.format.FormatterRegistry)
 	 */
@@ -93,7 +94,7 @@ public void addFormatters(FormatterRegistry registry) {
 		converter.setApplicationContext(context);
 	}
 
-	/* 
+	/*
 	 * (non-Javadoc)
 	 * @see org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter#addArgumentResolvers(java.util.List)
 	 */
@@ -111,14 +112,15 @@ public void addArgumentResolvers(List<HandlerMethodArgumentResolver> argumentRes
 		argumentResolvers.add(resolver);
 	}
 
-	/* 
+	/*
 	 * (non-Javadoc)
 	 * @see org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter#extendMessageConverters(java.util.List)
 	 */
 	@Override
 	public void extendMessageConverters(List<HttpMessageConverter<?>> converters) {
 
-		if (ClassUtils.isPresent("com.jayway.jsonpath.DocumentContext", context.getClassLoader())) {
+		if (ClassUtils.isPresent("com.jayway.jsonpath.DocumentContext", context.getClassLoader())
+				&& ClassUtils.isPresent("com.fasterxml.jackson.databind.ObjectMapper", context.getClassLoader())) {
 
 			ProjectingJackson2HttpMessageConverter converter = new ProjectingJackson2HttpMessageConverter(new ObjectMapper());
 			converter.setBeanClassLoader(context.getClassLoader());

src/test/java/org/springframework/data/web/config/SpringDataWebConfigurationIntegrationTests.java

@@ -0,0 +1,156 @@
+/*
+ * Copyright 2015-2017 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.web.config;
+
+import static org.hamcrest.Matchers.*;
+import static org.junit.Assert.*;
+import static org.springframework.test.util.ReflectionTestUtils.*;
+
+import java.net.URLClassLoader;
+import java.util.ArrayList;
+import java.util.List;
+
+import org.hamcrest.Matcher;
+import org.junit.Test;
+import org.springframework.beans.BeansException;
+import org.springframework.beans.factory.ObjectFactory;
+import org.springframework.context.support.GenericApplicationContext;
+import org.springframework.core.convert.ConversionService;
+import org.springframework.data.web.ProjectingJackson2HttpMessageConverter;
+import org.springframework.data.web.XmlBeamHttpMessageConverter;
+import org.springframework.http.converter.HttpMessageConverter;
+import org.springframework.instrument.classloading.ShadowingClassLoader;
+
+/**
+ * Integration test for {@link SpringDataWebConfiguration}.
+ *
+ * @author Christoph Strobl
+ * @author Jens Schauder
+ */
+public class SpringDataWebConfigurationIntegrationTests {
+
+	@Test // DATACMNS-987
+	public void shouldNotLoadJacksonConverterWhenJacksonNotPresent() {
+
+		SpringDataWebConfiguration config = createConfigWithClassLoaderExcluding("com.fasterxml.jackson");
+
+		List<HttpMessageConverter<?>> converters = new ArrayList<HttpMessageConverter<?>>();
+
+		config.extendMessageConverters(converters);
+
+		assertThat(converters, (Matcher) not(hasItem( //
+				instanceWithClassName(ProjectingJackson2HttpMessageConverter.class))));
+	}
+
+	@Test // DATACMNS-987
+	public void shouldNotLoadJacksonConverterWhenJaywayNotPresent() {
+
+		SpringDataWebConfiguration config = createConfigWithClassLoaderExcluding("com.jayway");
+
+		List<HttpMessageConverter<?>> converters = new ArrayList<HttpMessageConverter<?>>();
+
+		config.extendMessageConverters(converters);
+
+		assertThat(converters, (Matcher) not(hasItem( //
+				instanceWithClassName(ProjectingJackson2HttpMessageConverter.class))));
+	}
+
+	@Test // DATACMNS-987
+	public void shouldNotLoadXBeamConverterWhenXBeamNotPresent() throws Exception {
+
+		SpringDataWebConfiguration config = createConfigWithClassLoaderExcluding("org.xmlbeam");
+
+		List<HttpMessageConverter<?>> converters = new ArrayList<HttpMessageConverter<?>>();
+
+		config.extendMessageConverters(converters);
+
+		assertThat(converters, (Matcher) not(hasItem( //
+				instanceWithClassName(XmlBeamHttpMessageConverter.class))));
+	}
+
+	@Test // DATACMNS-987
+	public void shouldLoadAllConvertersWhenDependenciesArePresent() throws Exception {
+
+		SpringDataWebConfiguration config = createConfigWithClassLoaderExcluding("load.everything");
+
+		List<HttpMessageConverter<?>> converters = new ArrayList<HttpMessageConverter<?>>();
+
+		config.extendMessageConverters(converters);
+
+		assertThat(converters,
+				containsInAnyOrder( //
+						instanceWithClassName(XmlBeamHttpMessageConverter.class), //
+						instanceWithClassName(ProjectingJackson2HttpMessageConverter.class)));
+	}
+
+	private SpringDataWebConfiguration createConfigWithClassLoaderExcluding(String excludedClassNamePrefix) {
+
+		ClassLoader classLoader = initClassLoader(excludedClassNamePrefix);
+
+		SpringDataWebConfiguration config = new SpringDataWebConfiguration();
+		GenericApplicationContext applicationContext = new GenericApplicationContext();
+		applicationContext.setClassLoader(classLoader);
+
+		setField(config, "context", applicationContext);
+
+		return config;
+	}
+
+	/**
+	 * creates a Matcher that check if an object is an instance of a class with the same name as the provided class. This
+	 * is necessary since we are dealing with multiple classloaders which would make a simple instanceof fail all the time
+	 *
+	 * @param expectedClass the class that is expected (possibly loaded by a different classloader).
+	 * @return a Matcher
+	 */
+	private Matcher<Object> instanceWithClassName(Class<?> expectedClass) {
+		return hasProperty("class", hasProperty("name", equalTo(expectedClass.getName())));
+	}
+
+	private ClassLoader initClassLoader(final String excludedClassNamePrefix) {
+
+		return new ShadowingClassLoader(URLClassLoader.getSystemClassLoader()) {
+
+			@Override
+			public Class<?> loadClass(String name) throws ClassNotFoundException {
+
+				if (name.startsWith(excludedClassNamePrefix)) {
+					throw new ClassNotFoundException();
+				}
+
+				return super.loadClass(name);
+			}
+
+			@Override
+			protected Class<?> findClass(String name) throws ClassNotFoundException {
+
+				if (name.startsWith(excludedClassNamePrefix)) {
+					throw new ClassNotFoundException();
+				}
+
+				return super.findClass(name);
+			}
+		};
+	}
+
+	public static class ObjectFactoryImpl implements ObjectFactory<ConversionService> {
+
+		@Override
+		public ConversionService getObject() throws BeansException {
+			return null;
+		}
+	}
+}