org.springframework.core.convert.converter.GenericConverter.ConvertiblePair#org.springframework.core.GenericTypeResolver源码实例Demo

/**
 * This implementation resolves the type of annotation from generic metadata and
 * validates that (a) the annotation is in fact present on the importing
 * {@code @Configuration} class and (b) that the given annotation has an
 * {@linkplain #getAdviceModeAttributeName() advice mode attribute} of type
 * {@link AdviceMode}.
 * <p>The {@link #selectImports(AdviceMode)} method is then invoked, allowing the
 * concrete implementation to choose imports in a safe and convenient fashion.
 * @throws IllegalArgumentException if expected annotation {@code A} is not present
 * on the importing {@code @Configuration} class or if {@link #selectImports(AdviceMode)}
 * returns {@code null}
 */
@Override
public final String[] selectImports(AnnotationMetadata importingClassMetadata) {
	Class<?> annType = GenericTypeResolver.resolveTypeArgument(getClass(), AdviceModeImportSelector.class);
	Assert.state(annType != null, "Unresolvable type argument for AdviceModeImportSelector");

	AnnotationAttributes attributes = AnnotationConfigUtils.attributesFor(importingClassMetadata, annType);
	if (attributes == null) {
		throw new IllegalArgumentException(String.format(
				"@%s is not present on importing class '%s' as expected",
				annType.getSimpleName(), importingClassMetadata.getClassName()));
	}

	AdviceMode adviceMode = attributes.getEnum(getAdviceModeAttributeName());
	String[] imports = selectImports(adviceMode);
	if (imports == null) {
		throw new IllegalArgumentException("Unknown AdviceMode: " + adviceMode);
	}
	return imports;
}
 

@SuppressWarnings("unchecked")
private ApplicationContextInitializer<ConfigurableApplicationContext> loadInitializer(
		String className, ConfigurableApplicationContext wac) {
	try {
		Class<?> initializerClass = ClassUtils.forName(className, wac.getClassLoader());
		Class<?> initializerContextClass =
				GenericTypeResolver.resolveTypeArgument(initializerClass, ApplicationContextInitializer.class);
		if (initializerContextClass != null && !initializerContextClass.isInstance(wac)) {
			throw new ApplicationContextException(String.format(
					"Could not apply context initializer [%s] since its generic parameter [%s] " +
					"is not assignable from the type of application context used by this " +
					"framework servlet: [%s]", initializerClass.getName(), initializerContextClass.getName(),
					wac.getClass().getName()));
		}
		return BeanUtils.instantiateClass(initializerClass, ApplicationContextInitializer.class);
	}
	catch (ClassNotFoundException ex) {
		throw new ApplicationContextException(String.format("Could not load class [%s] specified " +
				"via 'contextInitializerClasses' init-param", className), ex);
	}
}
 

/**
 * Customize the {@link ConfigurableWebApplicationContext} created by this
 * ContextLoader after config locations have been supplied to the context
 * but before the context is <em>refreshed</em>.
 * <p>The default implementation {@linkplain #determineContextInitializerClasses(ServletContext)
 * determines} what (if any) context initializer classes have been specified through
 * {@linkplain #CONTEXT_INITIALIZER_CLASSES_PARAM context init parameters} and
 * {@linkplain ApplicationContextInitializer#initialize invokes each} with the
 * given web application context.
 * <p>Any {@code ApplicationContextInitializers} implementing
 * {@link org.springframework.core.Ordered Ordered} or marked with @{@link
 * org.springframework.core.annotation.Order Order} will be sorted appropriately.
 * @param sc the current servlet context
 * @param wac the newly created application context
 * @see #CONTEXT_INITIALIZER_CLASSES_PARAM
 * @see ApplicationContextInitializer#initialize(ConfigurableApplicationContext)
 */
protected void customizeContext(ServletContext sc, ConfigurableWebApplicationContext wac) {
	List<Class<ApplicationContextInitializer<ConfigurableApplicationContext>>> initializerClasses =
			determineContextInitializerClasses(sc);

	for (Class<ApplicationContextInitializer<ConfigurableApplicationContext>> initializerClass : initializerClasses) {
		Class<?> initializerContextClass =
				GenericTypeResolver.resolveTypeArgument(initializerClass, ApplicationContextInitializer.class);
		if (initializerContextClass != null && !initializerContextClass.isInstance(wac)) {
			throw new ApplicationContextException(String.format(
					"Could not apply context initializer [%s] since its generic parameter [%s] " +
					"is not assignable from the type of application context used by this " +
					"context loader: [%s]", initializerClass.getName(), initializerContextClass.getName(),
					wac.getClass().getName()));
		}
		this.contextInitializers.add(BeanUtils.instantiateClass(initializerClass));
	}

	AnnotationAwareOrderComparator.sort(this.contextInitializers);
	for (ApplicationContextInitializer<ConfigurableApplicationContext> initializer : this.contextInitializers) {
		initializer.initialize(wac);
	}
}
 

/**
 * Resolves the arguments for the given method. Delegates to {@link #resolveCommonArgument}.
 */
private Object[] resolveHandlerArguments(Method handlerMethod, Object handler,
		NativeWebRequest webRequest, Exception thrownException) throws Exception {

	Class<?>[] paramTypes = handlerMethod.getParameterTypes();
	Object[] args = new Object[paramTypes.length];
	Class<?> handlerType = handler.getClass();
	for (int i = 0; i < args.length; i++) {
		MethodParameter methodParam = new SynthesizingMethodParameter(handlerMethod, i);
		GenericTypeResolver.resolveParameterType(methodParam, handlerType);
		Class<?> paramType = methodParam.getParameterType();
		Object argValue = resolveCommonArgument(methodParam, webRequest, thrownException);
		if (argValue != WebArgumentResolver.UNRESOLVED) {
			args[i] = argValue;
		}
		else {
			throw new IllegalStateException("Unsupported argument [" + paramType.getName() +
					"] for @ExceptionHandler method: " + handlerMethod);
		}
	}
	return args;
}
 

public static void main(String[] args) throws NoSuchMethodException {

        // String 是 Comparable<String> 具体化
        displayReturnTypeGenericInfo(GenericTypeResolverDemo.class, Comparable.class, "getString");

        // ArrayList<Object> 是 List 泛型参数类型的具体化
        displayReturnTypeGenericInfo(GenericTypeResolverDemo.class, List.class, "getList");

        // StringList 也是 List 泛型参数类型的具体化
        displayReturnTypeGenericInfo(GenericTypeResolverDemo.class, List.class, "getStringList");

        // 具备 ParameterizedType 返回，否则 null

        // TypeVariable
        Map<TypeVariable, Type> typeVariableMap = GenericTypeResolver.getTypeVariableMap(StringList.class);
        System.out.println(typeVariableMap);
    }
 

@Before
public void setup() {
	@SuppressWarnings("resource")
	GenericApplicationContext cxt = new GenericApplicationContext();
	cxt.refresh();
	this.resolver = new HeaderMethodArgumentResolver(new DefaultConversionService(), cxt.getBeanFactory());

	Method method = ReflectionUtils.findMethod(getClass(), "handleMessage", (Class<?>[]) null);
	this.paramRequired = new SynthesizingMethodParameter(method, 0);
	this.paramNamedDefaultValueStringHeader = new SynthesizingMethodParameter(method, 1);
	this.paramSystemPropertyDefaultValue = new SynthesizingMethodParameter(method, 2);
	this.paramSystemPropertyName = new SynthesizingMethodParameter(method, 3);
	this.paramNotAnnotated = new SynthesizingMethodParameter(method, 4);
	this.paramOptional = new SynthesizingMethodParameter(method, 5);
	this.paramNativeHeader = new SynthesizingMethodParameter(method, 6);

	this.paramRequired.initParameterNameDiscovery(new DefaultParameterNameDiscoverer());
	GenericTypeResolver.resolveParameterType(this.paramRequired, HeaderMethodArgumentResolver.class);
}
 

/**
 * This implementation resolves the type of annotation from generic metadata and
 * validates that (a) the annotation is in fact present on the importing
 * {@code @Configuration} class and (b) that the given annotation has an
 * {@linkplain #getAdviceModeAttributeName() advice mode attribute} of type
 * {@link AdviceMode}.
 * <p>The {@link #selectImports(AdviceMode)} method is then invoked, allowing the
 * concrete implementation to choose imports in a safe and convenient fashion.
 * @throws IllegalArgumentException if expected annotation {@code A} is not present
 * on the importing {@code @Configuration} class or if {@link #selectImports(AdviceMode)}
 * returns {@code null}
 */
@Override
public final String[] selectImports(AnnotationMetadata importingClassMetadata) {
	Class<?> annType = GenericTypeResolver.resolveTypeArgument(getClass(), AdviceModeImportSelector.class);
	Assert.state(annType != null, "Unresolvable type argument for AdviceModeImportSelector");

	AnnotationAttributes attributes = AnnotationConfigUtils.attributesFor(importingClassMetadata, annType);
	if (attributes == null) {
		throw new IllegalArgumentException(String.format(
				"@%s is not present on importing class '%s' as expected",
				annType.getSimpleName(), importingClassMetadata.getClassName()));
	}

	AdviceMode adviceMode = attributes.getEnum(getAdviceModeAttributeName());
	String[] imports = selectImports(adviceMode);
	if (imports == null) {
		throw new IllegalArgumentException("Unknown AdviceMode: " + adviceMode);
	}
	return imports;
}
 

@Before
public void setup() throws Exception {
	@SuppressWarnings("resource")
	GenericApplicationContext cxt = new GenericApplicationContext();
	cxt.refresh();
	this.resolver = new HeaderMethodArgumentResolver(new DefaultConversionService(), cxt.getBeanFactory());

	Method method = getClass().getDeclaredMethod("handleMessage",
			String.class, String.class, String.class, String.class, String.class);
	this.paramRequired = new SynthesizingMethodParameter(method, 0);
	this.paramNamedDefaultValueStringHeader = new SynthesizingMethodParameter(method, 1);
	this.paramSystemProperty = new SynthesizingMethodParameter(method, 2);
	this.paramNotAnnotated = new SynthesizingMethodParameter(method, 3);
	this.paramNativeHeader = new SynthesizingMethodParameter(method, 4);

	this.paramRequired.initParameterNameDiscovery(new DefaultParameterNameDiscoverer());
	GenericTypeResolver.resolveParameterType(this.paramRequired, HeaderMethodArgumentResolver.class);
}
 

@SuppressWarnings("unchecked")
protected BeanPropertiesMapper(final NamespaceService namespaceService, final DictionaryService dictionaryService,
		final BeanPropertiesMapperConfigurer<T> configurer, final boolean reportNamespaceException) {
	Assert.notNull(namespaceService, "[Assertion failed] - the namespaceService argument must be null");
	Assert.notNull(dictionaryService, "[Assertion failed] - the dictionaryService argument must be null");

	this.namespaceService = namespaceService;
	this.dictionaryService = dictionaryService;
	this.reportNamespaceException = reportNamespaceException;

	Class<T> mappedClass = (Class<T>) GenericTypeResolver.resolveTypeArgument(getClass(),
			NodePropertiesMapper.class);
	if (mappedClass != null) {
		setMappedClass(mappedClass);
	}

	BeanPropertiesMapperConfigurer<T> confTmp = configurer;
	if (configurer == null) {
		if (this instanceof BeanPropertiesMapperConfigurer) {
			confTmp = ((BeanPropertiesMapperConfigurer<T>) this);
		}
	}

	this.configurer = confTmp;
}
 

/**
 * Resolves the arguments for the given method. Delegates to {@link #resolveCommonArgument}.
 */
private Object[] resolveHandlerArguments(Method handlerMethod, Object handler,
		NativeWebRequest webRequest, Exception thrownException) throws Exception {

	Class<?>[] paramTypes = handlerMethod.getParameterTypes();
	Object[] args = new Object[paramTypes.length];
	Class<?> handlerType = handler.getClass();
	for (int i = 0; i < args.length; i++) {
		MethodParameter methodParam = new SynthesizingMethodParameter(handlerMethod, i);
		GenericTypeResolver.resolveParameterType(methodParam, handlerType);
		Class<?> paramType = methodParam.getParameterType();
		Object argValue = resolveCommonArgument(methodParam, webRequest, thrownException);
		if (argValue != WebArgumentResolver.UNRESOLVED) {
			args[i] = argValue;
		}
		else {
			throw new IllegalStateException("Unsupported argument [" + paramType.getName() +
					"] for @ExceptionHandler method: " + handlerMethod);
		}
	}
	return args;
}
 

@SuppressWarnings("unchecked")
private ApplicationContextInitializer<ConfigurableApplicationContext> loadInitializer(
		String className, ConfigurableApplicationContext wac) {
	try {
		Class<?> initializerClass = ClassUtils.forName(className, wac.getClassLoader());
		Class<?> initializerContextClass =
				GenericTypeResolver.resolveTypeArgument(initializerClass, ApplicationContextInitializer.class);
		if (initializerContextClass != null && !initializerContextClass.isInstance(wac)) {
			throw new ApplicationContextException(String.format(
					"Could not apply context initializer [%s] since its generic parameter [%s] " +
					"is not assignable from the type of application context used by this " +
					"framework servlet: [%s]", initializerClass.getName(), initializerContextClass.getName(),
					wac.getClass().getName()));
		}
		return BeanUtils.instantiateClass(initializerClass, ApplicationContextInitializer.class);
	}
	catch (ClassNotFoundException ex) {
		throw new ApplicationContextException(String.format("Could not load class [%s] specified " +
				"via 'contextInitializerClasses' init-param", className), ex);
	}
}
 

/**
 * Customize the {@link ConfigurableWebApplicationContext} created by this
 * ContextLoader after config locations have been supplied to the context
 * but before the context is <em>refreshed</em>.
 * <p>The default implementation {@linkplain #determineContextInitializerClasses(ServletContext)
 * determines} what (if any) context initializer classes have been specified through
 * {@linkplain #CONTEXT_INITIALIZER_CLASSES_PARAM context init parameters} and
 * {@linkplain ApplicationContextInitializer#initialize invokes each} with the
 * given web application context.
 * <p>Any {@code ApplicationContextInitializers} implementing
 * {@link org.springframework.core.Ordered Ordered} or marked with @{@link
 * org.springframework.core.annotation.Order Order} will be sorted appropriately.
 * @param sc the current servlet context
 * @param wac the newly created application context
 * @see #CONTEXT_INITIALIZER_CLASSES_PARAM
 * @see ApplicationContextInitializer#initialize(ConfigurableApplicationContext)
 */
protected void customizeContext(ServletContext sc, ConfigurableWebApplicationContext wac) {
	List<Class<ApplicationContextInitializer<ConfigurableApplicationContext>>> initializerClasses =
			determineContextInitializerClasses(sc);

	for (Class<ApplicationContextInitializer<ConfigurableApplicationContext>> initializerClass : initializerClasses) {
		Class<?> initializerContextClass =
				GenericTypeResolver.resolveTypeArgument(initializerClass, ApplicationContextInitializer.class);
		if (initializerContextClass != null && !initializerContextClass.isInstance(wac)) {
			throw new ApplicationContextException(String.format(
					"Could not apply context initializer [%s] since its generic parameter [%s] " +
					"is not assignable from the type of application context used by this " +
					"context loader: [%s]", initializerClass.getName(), initializerContextClass.getName(),
					wac.getClass().getName()));
		}
		this.contextInitializers.add(BeanUtils.instantiateClass(initializerClass));
	}

	AnnotationAwareOrderComparator.sort(this.contextInitializers);
	for (ApplicationContextInitializer<ConfigurableApplicationContext> initializer : this.contextInitializers) {
		initializer.initialize(wac);
	}
}
 

/**
 * This implementation resolves the type of annotation from generic metadata and
 * validates that (a) the annotation is in fact present on the importing
 * {@code @Configuration} class and (b) that the given annotation has an
 * {@linkplain #getAdviceModeAttributeName() advice mode attribute} of type
 * {@link AdviceMode}.
 * <p>The {@link #selectImports(AdviceMode)} method is then invoked, allowing the
 * concrete implementation to choose imports in a safe and convenient fashion.
 * @throws IllegalArgumentException if expected annotation {@code A} is not present
 * on the importing {@code @Configuration} class or if {@link #selectImports(AdviceMode)}
 * returns {@code null}
 */
@Override
public final String[] selectImports(AnnotationMetadata importingClassMetadata) {
	Class<?> annoType = GenericTypeResolver.resolveTypeArgument(getClass(), AdviceModeImportSelector.class);
	AnnotationAttributes attributes = AnnotationConfigUtils.attributesFor(importingClassMetadata, annoType);
	if (attributes == null) {
		throw new IllegalArgumentException(String.format(
			"@%s is not present on importing class '%s' as expected",
			annoType.getSimpleName(), importingClassMetadata.getClassName()));
	}

	AdviceMode adviceMode = attributes.getEnum(this.getAdviceModeAttributeName());
	String[] imports = selectImports(adviceMode);
	if (imports == null) {
		throw new IllegalArgumentException(String.format("Unknown AdviceMode: '%s'", adviceMode));
	}
	return imports;
}
 

private void registerConversion(Object converter) {
	Class<?> type = converter.getClass();
	boolean isWriting = type.isAnnotationPresent(WritingConverter.class);
	boolean isReading = type.isAnnotationPresent(ReadingConverter.class);

	if (!isReading && !isWriting) {
		isReading = true;
		isWriting = true;
	}

	if (converter instanceof GenericConverter) {
		GenericConverter genericConverter = (GenericConverter) converter;
		for (ConvertiblePair pair : genericConverter.getConvertibleTypes()) {
			register(new ConvertibleContext(pair, isReading, isWriting));
		}
	} else if (converter instanceof Converter) {
		Class<?>[] arguments = GenericTypeResolver.resolveTypeArguments(converter.getClass(), Converter.class);
		register(new ConvertibleContext(arguments[0], arguments[1], isReading, isWriting));
	} else {
		throw new IllegalArgumentException(
				"Unsupported Converter type! Expected either GenericConverter if Converter.");
	}
}
 

@Override
public synchronized Class<?> getPropertyType() {
	if (this.propertyType == null) {
		if (this.readMethod != null) {
			this.propertyType = GenericTypeResolver.resolveReturnType(this.readMethod, this.beanClass);
		}
		else {
			MethodParameter writeMethodParam = getWriteMethodParameter();
			if (writeMethodParam != null) {
				this.propertyType = writeMethodParam.getParameterType();
			}
			else {
				this.propertyType = super.getPropertyType();
			}
		}
	}
	return this.propertyType;
}
 

@SuppressWarnings("unchecked")
private ApplicationContextInitializer<ConfigurableApplicationContext> loadInitializer(
		String className, ConfigurableApplicationContext wac) {
	try {
		Class<?> initializerClass = ClassUtils.forName(className, wac.getClassLoader());
		Class<?> initializerContextClass =
				GenericTypeResolver.resolveTypeArgument(initializerClass, ApplicationContextInitializer.class);
		if (initializerContextClass != null) {
			Assert.isAssignable(initializerContextClass, wac.getClass(), String.format(
					"Could not add context initializer [%s] since its generic parameter [%s] " +
					"is not assignable from the type of application context used by this " +
					"framework servlet [%s]: ", initializerClass.getName(), initializerContextClass.getName(),
					wac.getClass().getName()));
		}
		return BeanUtils.instantiateClass(initializerClass, ApplicationContextInitializer.class);
	}
	catch (Exception ex) {
		throw new IllegalArgumentException(String.format("Could not instantiate class [%s] specified " +
				"via 'contextInitializerClasses' init-param", className), ex);
	}
}
 

private JavaType getJavaType(Class<?> targetClass, @Nullable Object conversionHint) {
	if (conversionHint instanceof MethodParameter) {
		MethodParameter param = (MethodParameter) conversionHint;
		param = param.nestedIfOptional();
		if (Message.class.isAssignableFrom(param.getParameterType())) {
			param = param.nested();
		}
		Type genericParameterType = param.getNestedGenericParameterType();
		Class<?> contextClass = param.getContainingClass();
		Type type = GenericTypeResolver.resolveType(genericParameterType, contextClass);
		return this.objectMapper.getTypeFactory().constructType(type);
	}
	return this.objectMapper.constructType(targetClass);
}
 

private MethodParameter[] initMethodParameters() {
	int count = this.bridgedMethod.getParameterCount();
	MethodParameter[] result = new MethodParameter[count];
	for (int i = 0; i < count; i++) {
		HandlerMethodParameter parameter = new HandlerMethodParameter(i);
		GenericTypeResolver.resolveParameterType(parameter, this.beanType);
		result[i] = parameter;
	}
	return result;
}
 

@Before
public void setup() throws Exception {
	this.resolver = new DestinationVariableMethodArgumentResolver(new DefaultConversionService());

	Method method = getClass().getDeclaredMethod("handleMessage", String.class, String.class, String.class);
	this.paramAnnotated = new MethodParameter(method, 0);
	this.paramAnnotatedValue = new MethodParameter(method, 1);
	this.paramNotAnnotated = new MethodParameter(method, 2);

	this.paramAnnotated.initParameterNameDiscovery(new DefaultParameterNameDiscoverer());
	GenericTypeResolver.resolveParameterType(this.paramAnnotated, DestinationVariableMethodArgumentResolver.class);
	this.paramAnnotatedValue.initParameterNameDiscovery(new DefaultParameterNameDiscoverer());
	GenericTypeResolver.resolveParameterType(this.paramAnnotatedValue, DestinationVariableMethodArgumentResolver.class);
}
 

private Class<?>[] resolveTypeArguments() {
	Class<?>[] resolved = GenericTypeResolver.resolveTypeArguments(getClass(), ConvertingEncoderDecoderSupport.class);
	if (resolved == null) {
		throw new IllegalStateException("ConvertingEncoderDecoderSupport's generic types T and M " +
				"need to be substituted in subclass: " + getClass());
	}
	return resolved;
}
 

/**
 * Derive the model attribute name for the given return value. Results will be
 * based on:
 * <ol>
 * <li>the method {@code ModelAttribute} annotation value
 * <li>the declared return type if it is more specific than {@code Object}
 * <li>the actual return value type
 * </ol>
 * @param returnValue the value returned from a method invocation
 * @param returnType a descriptor for the return type of the method
 * @return the derived name (never {@code null} or empty String)
 */
public static String getNameForReturnValue(@Nullable Object returnValue, MethodParameter returnType) {
	ModelAttribute ann = returnType.getMethodAnnotation(ModelAttribute.class);
	if (ann != null && StringUtils.hasText(ann.value())) {
		return ann.value();
	}
	else {
		Method method = returnType.getMethod();
		Assert.state(method != null, "No handler method");
		Class<?> containingClass = returnType.getContainingClass();
		Class<?> resolvedType = GenericTypeResolver.resolveReturnType(method, containingClass);
		return Conventions.getVariableNameForReturnType(method, resolvedType, returnValue);
	}
}
 

private MethodParameter[] initMethodParameters() {
	int count = this.bridgedMethod.getParameterCount();
	MethodParameter[] result = new MethodParameter[count];
	for (int i = 0; i < count; i++) {
		HandlerMethodParameter parameter = new HandlerMethodParameter(i);
		GenericTypeResolver.resolveParameterType(parameter, this.beanType);
		result[i] = parameter;
	}
	return result;
}
 

@SuppressWarnings("unchecked")
private void invokeApplicationContextInitializers(ConfigurableApplicationContext context,
		MergedContextConfiguration mergedConfig) {

	Set<Class<? extends ApplicationContextInitializer<?>>> initializerClasses =
			mergedConfig.getContextInitializerClasses();
	if (initializerClasses.isEmpty()) {
		// no ApplicationContextInitializers have been declared -> nothing to do
		return;
	}

	List<ApplicationContextInitializer<ConfigurableApplicationContext>> initializerInstances = new ArrayList<>();
	Class<?> contextClass = context.getClass();

	for (Class<? extends ApplicationContextInitializer<?>> initializerClass : initializerClasses) {
		Class<?> initializerContextClass =
				GenericTypeResolver.resolveTypeArgument(initializerClass, ApplicationContextInitializer.class);
		if (initializerContextClass != null && !initializerContextClass.isInstance(context)) {
			throw new ApplicationContextException(String.format(
					"Could not apply context initializer [%s] since its generic parameter [%s] " +
					"is not assignable from the type of application context used by this " +
					"context loader: [%s]", initializerClass.getName(), initializerContextClass.getName(),
					contextClass.getName()));
		}
		initializerInstances.add((ApplicationContextInitializer<ConfigurableApplicationContext>) BeanUtils.instantiateClass(initializerClass));
	}

	AnnotationAwareOrderComparator.sort(initializerInstances);
	for (ApplicationContextInitializer<ConfigurableApplicationContext> initializer : initializerInstances) {
		initializer.initialize(context);
	}
}
 

/**
 * Resolve the prepared arguments stored in the given bean definition.
 */
private Object[] resolvePreparedArguments(String beanName, RootBeanDefinition mbd, BeanWrapper bw,
		Executable executable, Object[] argsToResolve, boolean fallback) {

	TypeConverter customConverter = this.beanFactory.getCustomTypeConverter();
	TypeConverter converter = (customConverter != null ? customConverter : bw);
	BeanDefinitionValueResolver valueResolver =
			new BeanDefinitionValueResolver(this.beanFactory, beanName, mbd, converter);
	Class<?>[] paramTypes = executable.getParameterTypes();

	Object[] resolvedArgs = new Object[argsToResolve.length];
	for (int argIndex = 0; argIndex < argsToResolve.length; argIndex++) {
		Object argValue = argsToResolve[argIndex];
		MethodParameter methodParam = MethodParameter.forExecutable(executable, argIndex);
		GenericTypeResolver.resolveParameterType(methodParam, executable.getDeclaringClass());
		if (argValue instanceof AutowiredArgumentMarker) {
			argValue = resolveAutowiredArgument(methodParam, beanName, null, converter, fallback);
		}
		else if (argValue instanceof BeanMetadataElement) {
			argValue = valueResolver.resolveValueIfNecessary("constructor argument", argValue);
		}
		else if (argValue instanceof String) {
			argValue = this.beanFactory.evaluateBeanDefinitionString((String) argValue, mbd);
		}
		Class<?> paramType = paramTypes[argIndex];
		try {
			resolvedArgs[argIndex] = converter.convertIfNecessary(argValue, paramType, methodParam);
		}
		catch (TypeMismatchException ex) {
			throw new UnsatisfiedDependencyException(
					mbd.getResourceDescription(), beanName, new InjectionPoint(methodParam),
					"Could not convert argument value of type [" + ObjectUtils.nullSafeClassName(argValue) +
					"] to required type [" + paramType.getName() + "]: " + ex.getMessage());
		}
	}
	return resolvedArgs;
}
 

/**
 * Introspect the factory method signatures on the given bean class,
 * trying to find a common {@code FactoryBean} object type declared there.
 * @param beanClass the bean class to find the factory method on
 * @param factoryMethodName the name of the factory method
 * @return the common {@code FactoryBean} object type, or {@code null} if none
 */
@Nullable
private Class<?> getTypeForFactoryBeanFromMethod(Class<?> beanClass, final String factoryMethodName) {

	/**
	 * Holder used to keep a reference to a {@code Class} value.
	 */
	class Holder {

		@Nullable
		Class<?> value = null;
	}

	final Holder objectType = new Holder();

	// CGLIB subclass methods hide generic parameters; look at the original user class.
	Class<?> fbClass = ClassUtils.getUserClass(beanClass);

	// Find the given factory method, taking into account that in the case of
	// @Bean methods, there may be parameters present.
	ReflectionUtils.doWithMethods(fbClass, method -> {
		if (method.getName().equals(factoryMethodName) &&
				FactoryBean.class.isAssignableFrom(method.getReturnType())) {
			Class<?> currentType = GenericTypeResolver.resolveReturnTypeArgument(method, FactoryBean.class);
			if (currentType != null) {
				objectType.value = ClassUtils.determineCommonAncestor(currentType, objectType.value);
			}
		}
	}, ReflectionUtils.USER_DECLARED_METHODS);

	return (objectType.value != null && Object.class != objectType.value ? objectType.value : null);
}
 

/**
 * Optionally set the concrete class that contains this dependency.
 * This may differ from the class that declares the parameter/field in that
 * it may be a subclass thereof, potentially substituting type variables.
 * @since 4.0
 */
public void setContainingClass(Class<?> containingClass) {
	this.containingClass = containingClass;
	this.resolvableType = null;
	if (this.methodParameter != null) {
		GenericTypeResolver.resolveParameterType(this.methodParameter, containingClass);
	}
}
 

private JavaType getJavaType(Class<?> targetClass, @Nullable Object conversionHint) {
	if (conversionHint instanceof MethodParameter) {
		MethodParameter param = (MethodParameter) conversionHint;
		param = param.nestedIfOptional();
		if (Message.class.isAssignableFrom(param.getParameterType())) {
			param = param.nested();
		}
		Type genericParameterType = param.getNestedGenericParameterType();
		Class<?> contextClass = param.getContainingClass();
		Type type = GenericTypeResolver.resolveType(genericParameterType, contextClass);
		return this.objectMapper.getTypeFactory().constructType(type);
	}
	return this.objectMapper.constructType(targetClass);
}
 

@Before
public void setup() throws Exception {
	this.resolver = new DestinationVariableMethodArgumentResolver(new DefaultConversionService());

	Method method = getClass().getDeclaredMethod("handleMessage", String.class, String.class, String.class);
	this.paramAnnotated = new MethodParameter(method, 0);
	this.paramAnnotatedValue = new MethodParameter(method, 1);
	this.paramNotAnnotated = new MethodParameter(method, 2);

	this.paramAnnotated.initParameterNameDiscovery(new DefaultParameterNameDiscoverer());
	GenericTypeResolver.resolveParameterType(this.paramAnnotated, DestinationVariableMethodArgumentResolver.class);
	this.paramAnnotatedValue.initParameterNameDiscovery(new DefaultParameterNameDiscoverer());
	GenericTypeResolver.resolveParameterType(this.paramAnnotatedValue, DestinationVariableMethodArgumentResolver.class);
}
 

static Class<?> getFieldType(Formatter<?> formatter) {
	Class<?> fieldType = GenericTypeResolver.resolveTypeArgument(formatter.getClass(), Formatter.class);
	if (fieldType == null && formatter instanceof DecoratingProxy) {
		fieldType = GenericTypeResolver.resolveTypeArgument(
				((DecoratingProxy) formatter).getDecoratedClass(), Formatter.class);
	}
	if (fieldType == null) {
		throw new IllegalArgumentException("Unable to extract the parameterized field type from Formatter [" +
				formatter.getClass().getName() + "]; does the class parameterize the <T> generic type?");
	}
	return fieldType;
}
 

@SuppressWarnings("unchecked")
static Class<? extends Annotation> getAnnotationType(AnnotationFormatterFactory<? extends Annotation> factory) {
	Class<? extends Annotation> annotationType = (Class<? extends Annotation>)
			GenericTypeResolver.resolveTypeArgument(factory.getClass(), AnnotationFormatterFactory.class);
	if (annotationType == null) {
		throw new IllegalArgumentException("Unable to extract parameterized Annotation type argument from " +
				"AnnotationFormatterFactory [" + factory.getClass().getName() +
				"]; does the factory parameterize the <A extends Annotation> generic type?");
	}
	return annotationType;
}