org.springframework.web.method.annotation
Class ExceptionHandlerMethodResolver

java.lang.Object
  org.springframework.web.method.annotation.ExceptionHandlerMethodResolver

public class ExceptionHandlerMethodResolver
extends java.lang.Object

Given a set of @ExceptionHandler methods at initialization, finds the best matching method mapped to an exception at runtime.

Exception mappings are extracted from the method @ExceptionHandler annotation or by looking for Throwable method arguments.

Since:

3.1

Author:

Rossen Stoyanchev

Field Summary

static ReflectionUtils.MethodFilter	EXCEPTION_HANDLER_METHODS A filter for selecting @ExceptionHandler methods.
private java.util.Map<java.lang.Class<? extends java.lang.Throwable>,java.lang.reflect.Method>	exceptionLookupCache
private java.util.Map<java.lang.Class<? extends java.lang.Throwable>,java.lang.reflect.Method>	mappedMethods
private static java.lang.reflect.Method	NO_METHOD_FOUND

Constructor Summary

ExceptionHandlerMethodResolver(java.lang.Class<?> handlerType)
A constructor that finds ExceptionHandler methods in a handler.

Method Summary

private void	addExceptionMapping(java.lang.Class<? extends java.lang.Throwable> exceptionType, java.lang.reflect.Method method)
private java.util.List<java.lang.Class<? extends java.lang.Throwable>>	detectMappedExceptions(java.lang.reflect.Method method) Detect the exceptions an @ExceptionHandler method is mapped to.
private java.lang.reflect.Method	getMappedMethod(java.lang.Class<? extends java.lang.Exception> exceptionType) Return the method mapped to the exception type, or null.
private void	init(java.util.Set<java.lang.reflect.Method> exceptionHandlerMethods)
java.lang.reflect.Method	resolveMethod(java.lang.Exception exception) Find a method to handle the given exception.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

NO_METHOD_FOUND

private static final java.lang.reflect.Method NO_METHOD_FOUND

mappedMethods

private final java.util.Map<java.lang.Class<? extends java.lang.Throwable>,java.lang.reflect.Method> mappedMethods

exceptionLookupCache

private final java.util.Map<java.lang.Class<? extends java.lang.Throwable>,java.lang.reflect.Method> exceptionLookupCache

EXCEPTION_HANDLER_METHODS

public static final ReflectionUtils.MethodFilter EXCEPTION_HANDLER_METHODS

A filter for selecting @ExceptionHandler methods.

Constructor Detail

ExceptionHandlerMethodResolver

public ExceptionHandlerMethodResolver(java.lang.Class<?> handlerType)

A constructor that finds ExceptionHandler methods in a handler.

Parameters:

handlerType - the handler to inspect for exception handler methods.

Throws:

java.lang.IllegalStateException - If an exception type is mapped to two methods.

java.lang.IllegalArgumentException - If an @ExceptionHandler method is not mapped to any exceptions.

Method Detail

init

private void init(java.util.Set<java.lang.reflect.Method> exceptionHandlerMethods)

detectMappedExceptions

private java.util.List<java.lang.Class<? extends java.lang.Throwable>> detectMappedExceptions(java.lang.reflect.Method method)

Detect the exceptions an @ExceptionHandler method is mapped to. If the method @ExceptionHandler annotation doesn't have any, scan the method signature for all arguments of type Throwable.

addExceptionMapping

private void addExceptionMapping(java.lang.Class<? extends java.lang.Throwable> exceptionType,
                                 java.lang.reflect.Method method)

resolveMethod

public java.lang.reflect.Method resolveMethod(java.lang.Exception exception)

Find a method to handle the given exception. If more than one match is found, the best match is selected via ExceptionDepthComparator.

Parameters:

exception - the exception

Returns:

an @ExceptionHandler method, or null

getMappedMethod

private java.lang.reflect.Method getMappedMethod(java.lang.Class<? extends java.lang.Exception> exceptionType)

Return the method mapped to the exception type, or null.