Add Support for Mockito spies

Add a @SpyBean annotation that can be used to create spies.

Fixes gh-5538

spring-boot-test/src/main/java/org/springframework/boot/test/mock/mockito/Definition.java

@@ -0,0 +1,79 @@
+/*
+ * Copyright 2012-2016 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.boot.test.mock.mockito;
+
+import org.springframework.util.ObjectUtils;
+
+/**
+ * Base class for {@link MockDefinition} and {@link SpyDefinition}.
+ *
+ * @author Phillip Webb
+ * @see DefinitionsParser
+ */
+abstract class Definition {
+
+	private static final int MULTIPLIER = 31;
+
+	private final String name;
+
+	private final MockReset reset;
+
+	Definition(String name, MockReset reset) {
+		this.name = name;
+		this.reset = (reset != null ? reset : MockReset.AFTER);
+	}
+
+	/**
+	 * Return the name for bean.
+	 * @return the name or {@code null}
+	 */
+	public String getName() {
+		return this.name;
+	}
+
+	/**
+	 * Return the mock reset mode.
+	 * @return the reset mode
+	 */
+	public MockReset getReset() {
+		return this.reset;
+	}
+
+	@Override
+	public int hashCode() {
+		int result = 1;
+		result = MULTIPLIER * result + ObjectUtils.nullSafeHashCode(this.name);
+		result = MULTIPLIER * result + ObjectUtils.nullSafeHashCode(this.reset);
+		return result;
+	}
+
+	@Override
+	public boolean equals(Object obj) {
+		if (obj == this) {
+			return true;
+		}
+		if (obj == null || !getClass().isAssignableFrom(obj.getClass())) {
+			return false;
+		}
+		Definition other = (Definition) obj;
+		boolean result = true;
+		result &= ObjectUtils.nullSafeEquals(this.name, other.name);
+		result &= ObjectUtils.nullSafeEquals(this.reset, other.reset);
+		return result;
+	}
+
+}

spring-boot-test/src/main/java/org/springframework/boot/test/mock/mockito/DefinitionsParser.java

@@ -33,24 +33,25 @@ import org.springframework.util.ReflectionUtils.FieldCallback;
 import org.springframework.util.StringUtils;
 
 /**
- * Parser to create {@link MockDefinition} from {@link MockBean @MockBean} annotations
- * declared on or in a class.
+ * Parser to create {@link MockDefinition} and {@link SpyDefinition} instances from
+ * {@link MockBean @MockBean} and {@link SpyBean @SpyBean} annotations declared on or in a
+ * class.
  *
  * @author Phillip Webb
  */
-class MockDefinitionsParser {
+class DefinitionsParser {
 
-	private final Set<MockDefinition> definitions;
+	private final Set<Definition> definitions;
 
-	private final Map<MockDefinition, Field> fields;
+	private final Map<Definition, Field> definitionFields;
 
-	MockDefinitionsParser() {
-		this(Collections.<MockDefinition>emptySet());
+	DefinitionsParser() {
+		this(Collections.<Definition>emptySet());
 	}
 
-	MockDefinitionsParser(Collection<? extends MockDefinition> existing) {
-		this.definitions = new LinkedHashSet<MockDefinition>();
-		this.fields = new LinkedHashMap<MockDefinition, Field>();
+	DefinitionsParser(Collection<? extends Definition> existing) {
+		this.definitions = new LinkedHashSet<Definition>();
+		this.definitionFields = new LinkedHashMap<Definition, Field>();
 		if (existing != null) {
 			this.definitions.addAll(existing);
 		}
@@ -72,12 +73,16 @@ class MockDefinitionsParser {
 	private void parseElement(AnnotatedElement element) {
 		for (MockBean annotation : AnnotationUtils.getRepeatableAnnotations(element,
 				MockBean.class, MockBeans.class)) {
-			parseAnnotation(annotation, element);
+			parseMockBeanAnnotation(annotation, element);
+		}
+		for (SpyBean annotation : AnnotationUtils.getRepeatableAnnotations(element,
+				SpyBean.class, SpyBeans.class)) {
+			parseSpyBeanAnnotation(annotation, element);
 		}
 	}
 
-	private void parseAnnotation(MockBean annotation, AnnotatedElement element) {
-		Set<Class<?>> classesToMock = getOrDeduceClassesToMock(annotation, element);
+	private void parseMockBeanAnnotation(MockBean annotation, AnnotatedElement element) {
+		Set<Class<?>> classesToMock = getOrDeduceClasses(element, annotation.value());
 		Assert.state(!classesToMock.isEmpty(),
 				"Unable to deduce class to mock from " + element);
 		if (StringUtils.hasLength(annotation.name())) {
@@ -88,30 +93,50 @@ class MockDefinitionsParser {
 			MockDefinition definition = new MockDefinition(annotation.name(), classToMock,
 					annotation.extraInterfaces(), annotation.answer(),
 					annotation.serializable(), annotation.reset());
-			boolean isNewDefinition = this.definitions.add(definition);
-			Assert.state(isNewDefinition, "Duplicate mock definition " + definition);
-			if (element instanceof Field) {
-				this.fields.put(definition, (Field) element);
-			}
+			addDefinition(element, definition, "mock");
 		}
 	}
 
-	private Set<Class<?>> getOrDeduceClassesToMock(MockBean annotation,
-			AnnotatedElement element) {
+	private void parseSpyBeanAnnotation(SpyBean annotation, AnnotatedElement element) {
+		Set<Class<?>> classesToSpy = getOrDeduceClasses(element, annotation.value());
+		Assert.state(!classesToSpy.isEmpty(),
+				"Unable to deduce class to spy from " + element);
+		if (StringUtils.hasLength(annotation.name())) {
+			Assert.state(classesToSpy.size() == 1,
+					"The name attribute can only be used when spying a single class");
+		}
+		for (Class<?> classToSpy : classesToSpy) {
+			SpyDefinition definition = new SpyDefinition(annotation.name(), classToSpy,
+					annotation.reset());
+			addDefinition(element, definition, "spy");
+		}
+	}
+
+	private void addDefinition(AnnotatedElement element, Definition definition,
+			String type) {
+		boolean isNewDefinition = this.definitions.add(definition);
+		Assert.state(isNewDefinition, "Duplicate " + type + " definition " + definition);
+		if (element instanceof Field) {
+			Field field = (Field) element;
+			this.definitionFields.put(definition, field);
+		}
+	}
+
+	private Set<Class<?>> getOrDeduceClasses(AnnotatedElement element, Class<?>[] value) {
 		Set<Class<?>> classes = new LinkedHashSet<Class<?>>();
-		classes.addAll(Arrays.asList(annotation.value()));
+		classes.addAll(Arrays.asList(value));
 		if (classes.isEmpty() && element instanceof Field) {
 			classes.add(((Field) element).getType());
 		}
 		return classes;
 	}
 
-	public Set<MockDefinition> getDefinitions() {
+	public Set<Definition> getDefinitions() {
 		return Collections.unmodifiableSet(this.definitions);
 	}
 
-	public Field getField(MockDefinition definition) {
-		return this.fields.get(definition);
+	public Field getField(Definition definition) {
+		return this.definitionFields.get(definition);
 	}
 
 }

spring-boot-test/src/main/java/org/springframework/boot/test/mock/mockito/MockBean.java

@@ -82,9 +82,9 @@ import org.springframework.test.context.junit4.SpringRunner;
 public @interface MockBean {
 
 	/**
-	 * The name of the bean that should be registered with the application context. If not
-	 * specified the name will either be generated or, if the mock replaces an existing
-	 * bean, the existing name will be used.
+	 * The name of the bean to register or replace. If not specified the name will either
+	 * be generated or, if the mock replaces an existing bean, the existing name will be
+	 * used.
 	 * @return the name of the bean
 	 */
 	String name() default "";

spring-boot-test/src/main/java/org/springframework/boot/test/mock/mockito/MockDefinition.java

@@ -35,12 +35,10 @@ import org.springframework.util.StringUtils;
  *
  * @author Phillip Webb
  */
-class MockDefinition {
+class MockDefinition extends Definition {
 
 	private static final int MULTIPLIER = 31;
 
-	private final String name;
-
 	private final Class<?> classToMock;
 
 	private final Set<Class<?>> extraInterfaces;
@@ -49,21 +47,18 @@ class MockDefinition {
 
 	private final boolean serializable;
 
-	private final MockReset reset;
-
 	MockDefinition(Class<?> classToMock) {
 		this(null, classToMock, null, null, false, null);
 	}
 
 	MockDefinition(String name, Class<?> classToMock, Class<?>[] extraInterfaces,
 			Answers answer, boolean serializable, MockReset reset) {
+		super(name, reset);
 		Assert.notNull(classToMock, "ClassToMock must not be null");
-		this.name = name;
 		this.classToMock = classToMock;
 		this.extraInterfaces = asClassSet(extraInterfaces);
 		this.answer = (answer != null ? answer : Answers.RETURNS_DEFAULTS);
 		this.serializable = serializable;
-		this.reset = (reset != null ? reset : MockReset.AFTER);
 	}
 
 	private Set<Class<?>> asClassSet(Class<?>[] classes) {
@@ -74,14 +69,6 @@ class MockDefinition {
 		return Collections.unmodifiableSet(classSet);
 	}
 
-	/**
-	 * Return the name for bean.
-	 * @return the name or {@code null}
-	 */
-	public String getName() {
-		return this.name;
-	}
-
 	/**
 	 * Return the classes that should be mocked.
 	 * @return the class to mock; never {@code null}
@@ -114,23 +101,13 @@ class MockDefinition {
 		return this.serializable;
 	}
 
-	/**
-	 * Return the mock reset mode.
-	 * @return the reset mode
-	 */
-	public MockReset getReset() {
-		return this.reset;
-	}
-
 	@Override
 	public int hashCode() {
-		int result = 1;
-		result = MULTIPLIER * result + ObjectUtils.nullSafeHashCode(this.name);
+		int result = super.hashCode();
 		result = MULTIPLIER * result + ObjectUtils.nullSafeHashCode(this.classToMock);
 		result = MULTIPLIER * result + ObjectUtils.nullSafeHashCode(this.extraInterfaces);
 		result = MULTIPLIER * result + ObjectUtils.nullSafeHashCode(this.answer);
 		result = MULTIPLIER * result + (this.serializable ? 1231 : 1237);
-		result = MULTIPLIER * result + ObjectUtils.nullSafeHashCode(this.reset);
 		return result;
 	}
 
@@ -143,32 +120,30 @@ class MockDefinition {
 			return false;
 		}
 		MockDefinition other = (MockDefinition) obj;
-		boolean result = true;
-		result &= ObjectUtils.nullSafeEquals(this.name, other.name);
+		boolean result = super.equals(obj);
 		result &= ObjectUtils.nullSafeEquals(this.classToMock, other.classToMock);
 		result &= ObjectUtils.nullSafeEquals(this.extraInterfaces, other.extraInterfaces);
 		result &= ObjectUtils.nullSafeEquals(this.answer, other.answer);
 		result &= this.serializable == other.serializable;
-		result &= ObjectUtils.nullSafeEquals(this.reset, other.reset);
 		return result;
 	}
 
 	@Override
 	public String toString() {
-		return new ToStringCreator(this).append("name", this.name)
+		return new ToStringCreator(this).append("name", getName())
 				.append("classToMock", this.classToMock)
 				.append("extraInterfaces", this.extraInterfaces)
 				.append("answer", this.answer).append("serializable", this.serializable)
-				.append("reset", this.reset).toString();
+				.append("reset", getReset()).toString();
 	}
 
 	public <T> T createMock() {
-		return createMock(this.name);
+		return createMock(getName());
 	}
 
 	@SuppressWarnings("unchecked")
 	public <T> T createMock(String name) {
-		MockSettings settings = MockReset.withSettings(this.reset);
+		MockSettings settings = MockReset.withSettings(getReset());
 		if (StringUtils.hasLength(name)) {
 			settings.name(name);
 		}

spring-boot-test/src/main/java/org/springframework/boot/test/mock/mockito/MockitoContextCustomizer.java

@@ -16,6 +16,7 @@
 
 package org.springframework.boot.test.mock.mockito;
 
+import java.util.LinkedHashSet;
 import java.util.Set;
 
 import org.springframework.beans.factory.support.BeanDefinitionRegistry;
@@ -30,10 +31,10 @@ import org.springframework.test.context.MergedContextConfiguration;
  */
 class MockitoContextCustomizer implements ContextCustomizer {
 
-	private final Set<MockDefinition> definitions;
+	private final Set<Definition> definitions;
 
-	MockitoContextCustomizer(Set<MockDefinition> definitions) {
-		this.definitions = definitions;
+	MockitoContextCustomizer(Set<? extends Definition> definitions) {
+		this.definitions = new LinkedHashSet<Definition>(definitions);
 	}
 
 	@Override

spring-boot-test/src/main/java/org/springframework/boot/test/mock/mockito/MockitoContextCustomizerFactory.java

@@ -34,7 +34,7 @@ class MockitoContextCustomizerFactory implements ContextCustomizerFactory {
 			List<ContextConfigurationAttributes> configAttributes) {
 		// We gather the explicit mock definitions here since they form part of the
 		// MergedContextConfiguration key. Different mocks need to have a different key
-		MockDefinitionsParser parser = new MockDefinitionsParser();
+		DefinitionsParser parser = new DefinitionsParser();
 		parser.parse(testClass);
 		return new MockitoContextCustomizer(parser.getDefinitions());
 	}

spring-boot-test/src/main/java/org/springframework/boot/test/mock/mockito/MockitoPostProcessor.java

@@ -34,6 +34,7 @@ import org.springframework.beans.factory.BeanFactory;
 import org.springframework.beans.factory.BeanFactoryAware;
 import org.springframework.beans.factory.config.BeanDefinition;
 import org.springframework.beans.factory.config.BeanFactoryPostProcessor;
+import org.springframework.beans.factory.config.BeanPostProcessor;
 import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
 import org.springframework.beans.factory.config.ConstructorArgumentValues;
 import org.springframework.beans.factory.config.ConstructorArgumentValues.ValueHolder;
@@ -66,7 +67,7 @@ import org.springframework.util.StringUtils;
  */
 public class MockitoPostProcessor extends InstantiationAwareBeanPostProcessorAdapter
 		implements BeanClassLoaderAware, BeanFactoryAware, BeanFactoryPostProcessor,
-		Ordered {
+		BeanPostProcessor, Ordered {
 
 	private static final String BEAN_NAME = MockitoPostProcessor.class.getName();
 
@@ -74,7 +75,7 @@ public class MockitoPostProcessor extends InstantiationAwareBeanPostProcessorAda
 			.getQualifiedAttributeName(ConfigurationClassPostProcessor.class,
 					"configurationClass");
 
-	private final Set<MockDefinition> mockDefinitions;
+	private final Set<Definition> definitions;
 
 	private ClassLoader classLoader;
 
@@ -82,17 +83,19 @@ public class MockitoPostProcessor extends InstantiationAwareBeanPostProcessorAda
 
 	private final BeanNameGenerator beanNameGenerator = new DefaultBeanNameGenerator();
 
-	private Map<MockDefinition, String> beanNameRegistry = new HashMap<MockDefinition, String>();
+	private Map<Definition, String> beanNameRegistry = new HashMap<Definition, String>();
 
 	private Map<Field, String> fieldRegistry = new HashMap<Field, String>();
 
+	private Map<String, SpyDefinition> spies = new HashMap<String, SpyDefinition>();
+
 	/**
 	 * Create a new {@link MockitoPostProcessor} instance with the given initial
 	 * definitions.
-	 * @param mockDefinitions the initial definitions
+	 * @param definitions the initial definitions
 	 */
-	public MockitoPostProcessor(Set<MockDefinition> mockDefinitions) {
-		this.mockDefinitions = mockDefinitions;
+	public MockitoPostProcessor(Set<Definition> definitions) {
+		this.definitions = definitions;
 	}
 
 	@Override
@@ -118,14 +121,14 @@ public class MockitoPostProcessor extends InstantiationAwareBeanPostProcessorAda
 
 	private void postProcessBeanFactory(ConfigurableListableBeanFactory beanFactory,
 			BeanDefinitionRegistry registry) {
-		MockDefinitionsParser parser = new MockDefinitionsParser(this.mockDefinitions);
+		DefinitionsParser parser = new DefinitionsParser(this.definitions);
 		for (Class<?> configurationClass : getConfigurationClasses(beanFactory)) {
 			parser.parse(configurationClass);
 		}
-		Set<MockDefinition> definitions = parser.getDefinitions();
-		for (MockDefinition definition : definitions) {
+		Set<Definition> definitions = parser.getDefinitions();
+		for (Definition definition : definitions) {
 			Field field = parser.getField(definition);
-			registerMock(beanFactory, registry, definition, field);
+			register(beanFactory, registry, definition, field);
 		}
 	}
 
@@ -152,20 +155,23 @@ public class MockitoPostProcessor extends InstantiationAwareBeanPostProcessorAda
 		return definitions;
 	}
 
-	void inject(Field field, Object target, MockDefinition definition) {
-		String beanName = this.beanNameRegistry.get(definition);
-		Assert.state(StringUtils.hasLength(beanName),
-				"No mock found for definition " + definition);
-		injectMock(field, target, beanName);
+	private void register(ConfigurableListableBeanFactory beanFactory,
+			BeanDefinitionRegistry registry, Definition definition, Field field) {
+		if (definition instanceof MockDefinition) {
+			registerMock(beanFactory, registry, (MockDefinition) definition, field);
+		}
+		else if (definition instanceof SpyDefinition) {
+			registerSpy(beanFactory, registry, (SpyDefinition) definition, field);
+		}
 	}
 
 	private void registerMock(ConfigurableListableBeanFactory beanFactory,
-			BeanDefinitionRegistry registry, MockDefinition mockDefinition, Field field) {
-		RootBeanDefinition beanDefinition = createBeanDefinition(mockDefinition);
-		String name = getBeanName(beanFactory, registry, mockDefinition, beanDefinition);
+			BeanDefinitionRegistry registry, MockDefinition definition, Field field) {
+		RootBeanDefinition beanDefinition = createBeanDefinition(definition);
+		String name = getBeanName(beanFactory, registry, definition, beanDefinition);
 		beanDefinition.getConstructorArgumentValues().addIndexedArgumentValue(1, name);
 		registry.registerBeanDefinition(name, beanDefinition);
-		this.beanNameRegistry.put(mockDefinition, name);
+		this.beanNameRegistry.put(definition, name);
 		if (field != null) {
 			this.fieldRegistry.put(field, name);
 		}
@@ -184,12 +190,12 @@ public class MockitoPostProcessor extends InstantiationAwareBeanPostProcessorAda
 
 	/**
 	 * Factory method used by defined beans to actually create the mock.
-	 * @param definition the mock definition
+	 * @param mockDefinition the mock definition
 	 * @param name the bean name
 	 * @return the mock instance
 	 */
-	protected final Object createMock(MockDefinition definition, String name) {
-		return definition.createMock(name + " bean");
+	protected final Object createMock(MockDefinition mockDefinition, String name) {
+		return mockDefinition.createMock(name + " bean");
 	}
 
 	private String getBeanName(ConfigurableListableBeanFactory beanFactory,
@@ -212,6 +218,60 @@ public class MockitoPostProcessor extends InstantiationAwareBeanPostProcessorAda
 				+ new TreeSet<String>(Arrays.asList(existingBeans)));
 	}
 
+	private void registerSpy(ConfigurableListableBeanFactory beanFactory,
+			BeanDefinitionRegistry registry, SpyDefinition spyDefinition, Field field) {
+		String[] existingBeans = beanFactory
+				.getBeanNamesForType(spyDefinition.getClassToSpy());
+		if (ObjectUtils.isEmpty(existingBeans)) {
+			createSpy(registry, spyDefinition, field);
+		}
+		else {
+			registerSpies(spyDefinition, field, existingBeans);
+		}
+	}
+
+	private void createSpy(BeanDefinitionRegistry registry, SpyDefinition spyDefinition,
+			Field field) {
+		RootBeanDefinition beanDefinition = new RootBeanDefinition(
+				spyDefinition.getClassToSpy());
+		String beanName = this.beanNameGenerator.generateBeanName(beanDefinition,
+				registry);
+		registry.registerBeanDefinition(beanName, beanDefinition);
+		registerSpy(spyDefinition, field, beanName);
+	}
+
+	private void registerSpies(SpyDefinition spyDefinition, Field field,
+			String[] existingBeans) {
+		if (field != null) {
+			Assert.state(field == null || existingBeans.length == 1,
+					"Unable to register spy bean "
+							+ spyDefinition.getClassToSpy().getName()
+							+ " expected a single existing bean to replace but found "
+							+ new TreeSet<String>(Arrays.asList(existingBeans)));
+		}
+		for (String beanName : existingBeans) {
+			registerSpy(spyDefinition, field, beanName);
+		}
+	}
+
+	private void registerSpy(SpyDefinition spyDefinition, Field field, String beanName) {
+		this.spies.put(beanName, spyDefinition);
+		this.beanNameRegistry.put(spyDefinition, beanName);
+		if (field != null) {
+			this.fieldRegistry.put(field, beanName);
+		}
+	}
+
+	@Override
+	public Object postProcessAfterInitialization(Object bean, String beanName)
+			throws BeansException {
+		SpyDefinition spyDefinition = this.spies.get(beanName);
+		if (spyDefinition != null) {
+			bean = spyDefinition.createSpy(beanName, bean);
+		}
+		return bean;
+	}
+
 	@Override
 	public PropertyValues postProcessPropertyValues(PropertyValues pvs,
 			PropertyDescriptor[] pds, final Object bean, String beanName)
@@ -231,18 +291,27 @@ public class MockitoPostProcessor extends InstantiationAwareBeanPostProcessorAda
 	private void postProcessField(Object bean, Field field) {
 		String beanName = this.fieldRegistry.get(field);
 		if (StringUtils.hasLength(beanName)) {
-			injectMock(field, bean, beanName);
+			inject(field, bean, beanName);
 		}
 	}
 
-	private void injectMock(Field field, Object target, String beanName) {
+	void inject(Field field, Object target, Definition definition) {
+		String beanName = this.beanNameRegistry.get(definition);
+		Assert.state(StringUtils.hasLength(beanName),
+				"No bean found for definition " + definition);
+		inject(field, target, beanName);
+	}
+
+	private void inject(Field field, Object target, String beanName) {
 		try {
 			field.setAccessible(true);
-			Object mockBean = this.beanFactory.getBean(beanName, field.getType());
-			ReflectionUtils.setField(field, target, mockBean);
+			Assert.state(ReflectionUtils.getField(field, target) == null,
+					"The field " + field + " cannot have an existing value");
+			Object bean = this.beanFactory.getBean(beanName, field.getType());
+			ReflectionUtils.setField(field, target, bean);
 		}
 		catch (Throwable ex) {
-			throw new BeanCreationException("Could not inject mock field: " + field, ex);
+			throw new BeanCreationException("Could not inject field: " + field, ex);
 		}
 	}
 
@@ -264,11 +333,11 @@ public class MockitoPostProcessor extends InstantiationAwareBeanPostProcessorAda
 	 * Register the processor with a {@link BeanDefinitionRegistry}. Not required when
 	 * using the {@link SpringRunner} as registration is automatic.
 	 * @param registry the bean definition registry
-	 * @param mockDefinitions the initial mock definitions
+	 * @param definitions the initial mock/spy definitions
 	 */
 	public static void register(BeanDefinitionRegistry registry,
-			Set<MockDefinition> mockDefinitions) {
-		register(registry, MockitoPostProcessor.class, mockDefinitions);
+			Set<Definition> definitions) {
+		register(registry, MockitoPostProcessor.class, definitions);
 	}
 
 	/**
@@ -276,18 +345,18 @@ public class MockitoPostProcessor extends InstantiationAwareBeanPostProcessorAda
 	 * using the {@link SpringRunner} as registration is automatic.
 	 * @param registry the bean definition registry
 	 * @param postProcessor the post processor class to register
-	 * @param mockDefinitions the initial mock definitions
+	 * @param definitions the initial mock/spy definitions
 	 */
 	@SuppressWarnings("unchecked")
 	public static void register(BeanDefinitionRegistry registry,
 			Class<? extends MockitoPostProcessor> postProcessor,
-			Set<MockDefinition> mockDefinitions) {
+			Set<Definition> definitions) {
 		BeanDefinition definition = getOrAddBeanDefinition(registry, postProcessor);
 		ValueHolder constructorArg = definition.getConstructorArgumentValues()
 				.getIndexedArgumentValue(0, Set.class);
-		Set<MockDefinition> existing = (Set<MockDefinition>) constructorArg.getValue();
-		if (mockDefinitions != null) {
-			existing.addAll(mockDefinitions);
+		Set<Definition> existing = (Set<Definition>) constructorArg.getValue();
+		if (definitions != null) {
+			existing.addAll(definitions);
 		}
 	}
 

spring-boot-test/src/main/java/org/springframework/boot/test/mock/mockito/MockitoTestExecutionListener.java

@@ -38,10 +38,11 @@ import org.springframework.util.ReflectionUtils.FieldCallback;
  *
  * @author Phillip Webb
  */
-class MockitoInitializeTestExecutionListener extends AbstractTestExecutionListener {
+class MockitoTestExecutionListener extends AbstractTestExecutionListener {
 
 	@Override
 	public void prepareTestInstance(TestContext testContext) throws Exception {
+		System.out.println("Prepare");
 		if (hasMockitoAnnotations(testContext)) {
 			MockitoAnnotations.initMocks(testContext.getTestInstance());
 		}
@@ -55,18 +56,18 @@ class MockitoInitializeTestExecutionListener extends AbstractTestExecutionListen
 	}
 
 	private void injectFields(TestContext testContext) {
-		MockDefinitionsParser parser = new MockDefinitionsParser();
+		DefinitionsParser parser = new DefinitionsParser();
 		parser.parse(testContext.getTestClass());
 		if (!parser.getDefinitions().isEmpty()) {
 			injectFields(testContext, parser);
 		}
 	}
 
-	private void injectFields(TestContext testContext, MockDefinitionsParser parser) {
+	private void injectFields(TestContext testContext, DefinitionsParser parser) {
 		ApplicationContext applicationContext = testContext.getApplicationContext();
 		MockitoPostProcessor postProcessor = applicationContext
 				.getBean(MockitoPostProcessor.class);
-		for (MockDefinition definition : parser.getDefinitions()) {
+		for (Definition definition : parser.getDefinitions()) {
 			Field field = parser.getField(definition);
 			if (field != null) {
 				postProcessor.inject(field, testContext.getTestInstance(), definition);

spring-boot-test/src/main/java/org/springframework/boot/test/mock/mockito/SpyBean.java

@@ -0,0 +1,119 @@
+/*
+ * Copyright 2012-2016 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.boot.test.mock.mockito;
+
+import java.lang.annotation.Documented;
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Repeatable;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+import org.junit.runner.RunWith;
+
+import org.springframework.context.ApplicationContext;
+import org.springframework.core.annotation.AliasFor;
+import org.springframework.test.context.junit4.SpringRunner;
+
+/**
+ * Annotation that can be used to appy Mockto spies to a Spring
+ * {@link ApplicationContext}. Can be used as a class level annotation or on fields in
+ * either {@code @Configuration} classes, or test classes that are
+ * {@link RunWith @RunWith} the {@link SpringRunner}.
+ * <p>
+ * Spies can be applied by type or by {@link #name() bean name}. All beans in the context
+ * of the same type will be wrapped with the spy, if no existing bean is defined a new one
+ * will be added.
+ * <p>
+ * When {@code @SpyBean} is used on a field, as well as being registered in the
+ * application context, the spy will also be injected into the field. Typical usage might
+ * be: <pre class="code">
+ * &#064;RunWith(SpringRunner.class)
+ * public class ExampleTests {
+ *
+ *     &#064;SpyBean
+ *     private ExampleService service;
+ *
+ *     &#064;Autowired
+ *     private UserOfService userOfService;
+ *
+ *     &#064;Test
+ *     public void testUserOfService() {
+ *         String actual = this.userOfService.makeUse();
+ *         assertEquals("Was: Hello", actual);
+ *         verify(this.service).greet();
+ *     }
+ *
+ *     &#064;Configuration
+ *     &#064;Import(UserOfService.class) // A &#064;Component injected with ExampleService
+ *     static class Config {
+ *     }
+ *
+ *
+ * }
+ * </pre>
+ * <p>
+ * This annotation is {@code @Repeatable} and may be specified multiple times when working
+ * with Java 8 or contained within an {@link SpyBeans @SpyBeans} annotation.
+ *
+ * @author Phillip Webb
+ * @since 1.4.0
+ * @see MockitoPostProcessor
+ */
+@Target({ ElementType.TYPE, ElementType.FIELD })
+@Retention(RetentionPolicy.RUNTIME)
+@Documented
+@Repeatable(SpyBeans.class)
+public @interface SpyBean {
+
+	/**
+	 * The name of the bean to spy. If not specified the name will either be generated or,
+	 * if the spy is for an existing bean, the existing name will be used.
+	 * @return the name of the bean
+	 */
+	String name() default "";
+
+	/**
+	 * The classes to spy. This is an alias of {@link #classes()} which can be used for
+	 * brevity if no other attributes are defined. See {@link #classes()} for details.
+	 * @return the classes to mock
+	 */
+	@AliasFor("classes")
+	Class<?>[] value() default {};
+
+	/**
+	 * The classes to spy. Each class specified here will result in a spy being applied.
+	 * Classes can be omitted when the annotation is used on a field.
+	 * <p>
+	 * When {@code @MockBean} also defines a {@code name} this attribute can only contain
+	 * a single value.
+	 * <p>
+	 * If this is the only attribute specified consider using the {@code value} alias
+	 * instead.
+	 * @return the classes to mock
+	 */
+	@AliasFor("value")
+	Class<?>[] classes() default {};
+
+	/**
+	 * The reset mode to apply to the spied bean. The default is {@link MockReset#AFTER}
+	 * meaning that spies are automatically reset after each test method is invoked.
+	 * @return the reset mode
+	 */
+	MockReset reset() default MockReset.AFTER;
+
+}

spring-boot-test/src/main/java/org/springframework/boot/test/mock/mockito/SpyBeans.java

@@ -0,0 +1,47 @@
+/*
+ * Copyright 2012-2016 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.boot.test.mock.mockito;
+
+import java.lang.annotation.Documented;
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+/**
+ * Container annotation that aggregates several {@link SpyBean} annotations.
+ * <p>
+ * Can be used natively, declaring several nested {@link SpyBean} annotations. Can also be
+ * used in conjunction with Java 8's support for <em>repeatable annotations</em>, where
+ * {@link SpyBean} can simply be declared several times on the same
+ * {@linkplain ElementType#TYPE type}, implicitly generating this container annotation.
+ *
+ * @author Phillip Webb
+ * @since 1.4.0
+ */
+@Retention(RetentionPolicy.RUNTIME)
+@Target(ElementType.TYPE)
+@Documented
+public @interface SpyBeans {
+
+	/**
+	 * Return the contained {@link SpyBean} annotations.
+	 * @return the spy beans
+	 */
+	SpyBean[] value();
+
+}

spring-boot-test/src/main/java/org/springframework/boot/test/mock/mockito/SpyDefinition.java

@@ -0,0 +1,100 @@
+/*
+ * Copyright 2012-2016 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.boot.test.mock.mockito;
+
+import org.mockito.MockSettings;
+import org.mockito.Mockito;
+import org.mockito.internal.util.MockUtil;
+
+import org.springframework.core.style.ToStringCreator;
+import org.springframework.util.Assert;
+import org.springframework.util.ObjectUtils;
+import org.springframework.util.StringUtils;
+
+/**
+ * A complete definition that can be used to create a Mockito spy.
+ *
+ * @author Phillip Webb
+ */
+class SpyDefinition extends Definition {
+
+	private MockUtil mockUtil = new MockUtil();
+
+	private static final int MULTIPLIER = 31;
+
+	private final Class<?> classToSpy;
+
+	SpyDefinition(String name, Class<?> classToSpy, MockReset reset) {
+		super(name, reset);
+		Assert.notNull(classToSpy, "ClassToSpy must not be null");
+		this.classToSpy = classToSpy;
+
+	}
+
+	public Class<?> getClassToSpy() {
+		return this.classToSpy;
+	}
+
+	@Override
+	public int hashCode() {
+		int result = super.hashCode();
+		result = MULTIPLIER * result + ObjectUtils.nullSafeHashCode(this.classToSpy);
+		return result;
+	}
+
+	@Override
+	public boolean equals(Object obj) {
+		if (obj == this) {
+			return true;
+		}
+		if (obj == null || obj.getClass() != getClass()) {
+			return false;
+		}
+		SpyDefinition other = (SpyDefinition) obj;
+		boolean result = super.equals(obj);
+		result &= ObjectUtils.nullSafeEquals(this.classToSpy, other.classToSpy);
+		return result;
+	}
+
+	@Override
+	public String toString() {
+		return new ToStringCreator(this).append("name", getName())
+				.append("classToSpy", this.classToSpy).append("reset", getReset())
+				.toString();
+	}
+
+	public <T> T createSpy(Object instance) {
+		return createSpy(getName(), instance);
+	}
+
+	@SuppressWarnings("unchecked")
+	public <T> T createSpy(String name, Object instance) {
+		Assert.notNull(instance, "Instance must not be null");
+		Assert.isInstanceOf(this.classToSpy, instance);
+		if (this.mockUtil.isSpy(instance)) {
+			return (T) instance;
+		}
+		MockSettings settings = MockReset.withSettings(getReset());
+		if (StringUtils.hasLength(name)) {
+			settings.name(name);
+		}
+		settings.spiedInstance(instance);
+		settings.defaultAnswer(Mockito.CALLS_REAL_METHODS);
+		return (T) Mockito.mock(instance.getClass(), settings);
+	}
+
+}

spring-boot-test/src/main/resources/META-INF/spring.factories

@@ -7,5 +7,5 @@ org.springframework.boot.test.mock.mockito.MockitoContextCustomizerFactory
 
 # Test Execution Listeners
 org.springframework.test.context.TestExecutionListener=\
-org.springframework.boot.test.mock.mockito.MockitoInitializeTestExecutionListener,\
+org.springframework.boot.test.mock.mockito.MockitoTestExecutionListener,\
 org.springframework.boot.test.mock.mockito.ResetMocksTestExecutionListener