org.springframework.messaging.handler

Class HandlerMethod

java.lang.Object

org.springframework.messaging.handler.HandlerMethod

Direct Known Subclasses:

InvocableHandlerMethod, InvocableHandlerMethod

public class HandlerMethod
extends Object

Encapsulates information about a handler method consisting of a method and a bean. Provides convenient access to method parameters, the method return value, method annotations, etc.

The class may be created with a bean instance or with a bean name (e.g. lazy-init bean, prototype bean). Use createWithResolvedBean() to obtain a HandlerMethod instance with a bean instance resolved through the associated BeanFactory.

Since:

4.0

Author:

Arjen Poutsma, Rossen Stoyanchev, Juergen Hoeller

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
protected class	HandlerMethod.HandlerMethodParameter A MethodParameter with HandlerMethod-specific behavior.

Field Summary

Fields

Modifier and Type	Field and Description
static Log	defaultLogger Public for wrapping with fallback logger.
protected Log	logger

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	HandlerMethod(HandlerMethod handlerMethod) Copy constructor for use in subclasses.
	HandlerMethod(Object bean, Method method) Create an instance from a bean instance and a method.
	HandlerMethod(Object bean, String methodName, Class<?>... parameterTypes) Create an instance from a bean instance, method name, and parameter types.
	HandlerMethod(String beanName, BeanFactory beanFactory, Method method) Create an instance from a bean name, a method, and a BeanFactory.

Method Summary

Modifier and Type	Method and Description
protected void	assertTargetBean(Method method, Object targetBean, Object[] args) Assert that the target bean class is an instance of the class where the given method is declared.
HandlerMethod	createWithResolvedBean() If the provided instance contains a bean name rather than an object instance, the bean name is resolved before a HandlerMethod is created and returned.
boolean	equals(Object other)
protected static Object	findProvidedArgument(MethodParameter parameter, Object... providedArgs)
protected static String	formatArgumentError(MethodParameter param, String message)
protected String	formatInvokeError(String text, Object[] args)
Object	getBean() Return the bean for this handler method.
Class<?>	getBeanType() This method returns the type of the handler for this handler method.
protected Method	getBridgedMethod() If the bean method is a bridge method, this method returns the bridged (user-defined) method.
Log	getLogger() Return the currently configured Logger.
Method	getMethod() Return the method for this handler method.
<A extends Annotation> A	getMethodAnnotation(Class<A> annotationType) Return a single annotation on the underlying method traversing its super methods if no annotation can be found on the given method itself.
MethodParameter[]	getMethodParameters() Return the method parameters for this handler method.
HandlerMethod	getResolvedFromHandlerMethod() Return the HandlerMethod from which this HandlerMethod instance was resolved via createWithResolvedBean().
MethodParameter	getReturnType() Return the HandlerMethod return type.
MethodParameter	getReturnValueType(Object returnValue) Return the actual return value type.
String	getShortLogMessage() Return a short representation of this handler method for log message purposes.
int	hashCode()
<A extends Annotation> boolean	hasMethodAnnotation(Class<A> annotationType) Return whether the parameter is declared with the given annotation type.
boolean	isVoid() Return true if the method return type is void, false otherwise.
void	setLogger(Log logger) Set an alternative logger to use than the one based on the class name.
String	toString()

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

defaultLogger

public static final Log defaultLogger

Public for wrapping with fallback logger.

logger

protected Log logger

Constructor Detail

HandlerMethod

public HandlerMethod(Object bean,
                     Method method)

Create an instance from a bean instance and a method.

HandlerMethod

public HandlerMethod(Object bean,
                     String methodName,
                     Class<?>... parameterTypes)
              throws NoSuchMethodException

Create an instance from a bean instance, method name, and parameter types.

Throws:

NoSuchMethodException - when the method cannot be found

HandlerMethod

public HandlerMethod(String beanName,
                     BeanFactory beanFactory,
                     Method method)

Create an instance from a bean name, a method, and a BeanFactory. The method createWithResolvedBean() may be used later to re-create the HandlerMethod with an initialized bean.

HandlerMethod

protected HandlerMethod(HandlerMethod handlerMethod)

Copy constructor for use in subclasses.

Method Detail

setLogger

public void setLogger(Log logger)

Set an alternative logger to use than the one based on the class name.

Parameters:

logger - the logger to use

Since:

5.1

getLogger

public Log getLogger()

Return the currently configured Logger.

Since:

5.1

getBean

public Object getBean()

Return the bean for this handler method.

getMethod

public Method getMethod()

Return the method for this handler method.

getBeanType

public Class<?> getBeanType()

This method returns the type of the handler for this handler method.

Note that if the bean type is a CGLIB-generated class, the original user-defined class is returned.

getBridgedMethod

protected Method getBridgedMethod()

If the bean method is a bridge method, this method returns the bridged (user-defined) method. Otherwise, it returns the same method as getMethod().

getMethodParameters

public MethodParameter[] getMethodParameters()

Return the method parameters for this handler method.

getReturnType

public MethodParameter getReturnType()

Return the HandlerMethod return type.

getReturnValueType

public MethodParameter getReturnValueType(@Nullable
                                          Object returnValue)

Return the actual return value type.

isVoid

public boolean isVoid()

Return true if the method return type is void, false otherwise.

getMethodAnnotation

@Nullable
public <A extends Annotation> A getMethodAnnotation(Class<A> annotationType)

Return a single annotation on the underlying method traversing its super methods if no annotation can be found on the given method itself.

Also supports merged composed annotations with attribute overrides as of Spring Framework 4.3.

Parameters:

annotationType - the type of annotation to introspect the method for

Returns:

the annotation, or null if none found

See Also:

AnnotatedElementUtils.findMergedAnnotation(java.lang.reflect.AnnotatedElement, java.lang.Class<A>)

hasMethodAnnotation

public <A extends Annotation> boolean hasMethodAnnotation(Class<A> annotationType)

Return whether the parameter is declared with the given annotation type.

Parameters:

annotationType - the annotation type to look for

Since:

4.3

See Also:

AnnotatedElementUtils.hasAnnotation(java.lang.reflect.AnnotatedElement, java.lang.Class<? extends java.lang.annotation.Annotation>)

getResolvedFromHandlerMethod

@Nullable
public HandlerMethod getResolvedFromHandlerMethod()

Return the HandlerMethod from which this HandlerMethod instance was resolved via createWithResolvedBean().

Since:

4.3

createWithResolvedBean

public HandlerMethod createWithResolvedBean()

If the provided instance contains a bean name rather than an object instance, the bean name is resolved before a HandlerMethod is created and returned.

getShortLogMessage

public String getShortLogMessage()

Return a short representation of this handler method for log message purposes.

equals

public boolean equals(@Nullable
                      Object other)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

toString

public String toString()

Overrides:

toString in class Object

findProvidedArgument

@Nullable
protected static Object findProvidedArgument(MethodParameter parameter,
                                                       @Nullable
                                                       Object... providedArgs)

formatArgumentError

protected static String formatArgumentError(MethodParameter param,
                                            String message)

assertTargetBean

protected void assertTargetBean(Method method,
                                Object targetBean,
                                Object[] args)

Assert that the target bean class is an instance of the class where the given method is declared. In some cases the actual endpoint instance at request- processing time may be a JDK dynamic proxy (lazy initialization, prototype beans, and others). Endpoint classes that require proxying should prefer class-based proxy mechanisms.

formatInvokeError

protected String formatInvokeError(String text,
                                   Object[] args)