Spring Framework

org.springframework.aop
Interface MethodMatcher

All Known Subinterfaces:
IntroductionAwareMethodMatcher
All Known Implementing Classes:
AbstractRegexpMethodPointcut, AnnotationMethodMatcher, AspectJExpressionPointcut, ControlFlowPointcut, DynamicMethodMatcher, DynamicMethodMatcherPointcut, JdkRegexpMethodPointcut, NameMatchMethodPointcut, StaticMethodMatcher, StaticMethodMatcherPointcut, StaticMethodMatcherPointcutAdvisor

public interface MethodMatcher

Part of a Pointcut: Checks whether the target method is eligible for advice.

A MethodMatcher may be evaluated statically or at runtime (dynamically). Static matching involves method and (possibly) method attributes. Dynamic matching also makes arguments for a particular call available, and any effects of running previous advice applying to the joinpoint.

If an implementation returns false from its isRuntime() method, evaluation can be performed statically, and the result will be the same for all invocations of this method, whatever their arguments. This means that if the isRuntime() method returns false, the 3-arg matches(java.lang.reflect.Method, Class, Object[]) method will never be invoked.

If an implementation returns true from its 2-arg matches(java.lang.reflect.Method, Class) method and its isRuntime() method returns true, the 3-arg matches(java.lang.reflect.Method, Class, Object[]) method will be invoked immediately before each potential execution of the related advice, to decide whether the advice should run. All previous advice, such as earlier interceptors in an interceptor chain, will have run, so any state changes they have produced in parameters or ThreadLocal state will be available at the time of evaluation.

Since:
11.11.2003
Author:
Rod Johnson
See Also:
Pointcut, ClassFilter

Field Summary
static MethodMatcher TRUE
          Canonical instance that matches all methods.
 
Method Summary
 boolean isRuntime()
          Is this MethodMatcher dynamic, that is, must a final call be made on the matches(java.lang.reflect.Method, Class, Object[]) method at runtime even if the 2-arg matches method returns true?
 boolean matches(java.lang.reflect.Method method, java.lang.Class<?> targetClass)
          Perform static checking whether the given method matches.
 boolean matches(java.lang.reflect.Method method, java.lang.Class<?> targetClass, java.lang.Object[] args)
          Check whether there a runtime (dynamic) match for this method, which must have matched statically.
 

Field Detail

TRUE

static final MethodMatcher TRUE
Canonical instance that matches all methods.

Method Detail

matches

boolean matches(java.lang.reflect.Method method,
                java.lang.Class<?> targetClass)
Perform static checking whether the given method matches. If this returns false or if the isRuntime() method returns false, no runtime check (i.e. no. matches(java.lang.reflect.Method, Class, Object[]) call) will be made.

Parameters:
method - the candidate method
targetClass - the target class (may be null, in which case the candidate class must be taken to be the method's declaring class)
Returns:
whether or not this method matches statically

isRuntime

boolean isRuntime()
Is this MethodMatcher dynamic, that is, must a final call be made on the matches(java.lang.reflect.Method, Class, Object[]) method at runtime even if the 2-arg matches method returns true?

Can be invoked when an AOP proxy is created, and need not be invoked again before each method invocation,

Returns:
whether or not a runtime match via the 3-arg matches(java.lang.reflect.Method, Class, Object[]) method is required if static matching passed

matches

boolean matches(java.lang.reflect.Method method,
                java.lang.Class<?> targetClass,
                java.lang.Object[] args)
Check whether there a runtime (dynamic) match for this method, which must have matched statically.

This method is invoked only if the 2-arg matches method returns true for the given method and target class, and if the isRuntime() method returns true. Invoked immediately before potential running of the advice, after any advice earlier in the advice chain has run.

Parameters:
method - the candidate method
targetClass - the target class (may be null, in which case the candidate class must be taken to be the method's declaring class)
args - arguments to the method
Returns:
whether there's a runtime match
See Also:
matches(Method, Class)

Spring Framework