org.springframework.util
Class MethodInvoker

java.lang.Object
  org.springframework.util.MethodInvoker

Direct Known Subclasses:

ArgumentConvertingMethodInvoker

public class MethodInvoker
extends Object

Helper class that allows for specifying a method to invoke in a declarative fashion, be it static or non-static.

Usage: Specify "targetClass"/"targetMethod" or "targetObject"/"targetMethod", optionally specify arguments, prepare the invoker. Afterwards, you may invoke the method any number of times, obtaining the invocation result.

Typically not used directly but via its subclasses MethodInvokingFactoryBean and MethodInvokingJobDetailFactoryBean.

Since:

19.02.2004

Author:

Colin Sampaleanu, Juergen Hoeller

See Also:

prepare(), invoke(), MethodInvokingFactoryBean, MethodInvokingJobDetailFactoryBean

Constructor Summary

MethodInvoker()

Method Summary

protected Method	findMatchingMethod() Find a matching method with the specified name for the specified arguments.
Object[]	getArguments() Retrun the arguments for the method invocation.
Method	getPreparedMethod() Return the prepared Method object that will be invoked.
Class	getTargetClass() Return the target class on which to call the target method.
String	getTargetMethod() Return the name of the method to be invoked.
Object	getTargetObject() Return the target object on which to call the target method.
Object	invoke() Invoke the specified method.
boolean	isPrepared() Return whether this invoker has been prepared already, i.e. whether it allows access to getPreparedMethod() already.
void	prepare() Prepare the specified method.
protected Class	resolveClassName(String className) Resolve the given class name into a Class.
void	setArguments(Object[] arguments) Set arguments for the method invocation.
void	setStaticMethod(String staticMethod) Set a fully qualified static method name to invoke, e.g.
void	setTargetClass(Class targetClass) Set the target class on which to call the target method.
void	setTargetMethod(String targetMethod) Set the name of the method to be invoked.
void	setTargetObject(Object targetObject) Set the target object on which to call the target method.

Methods inherited from class java.lang.Object

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

Constructor Detail

MethodInvoker

public MethodInvoker()

Method Detail

setTargetClass

public void setTargetClass(Class targetClass)

Set the target class on which to call the target method. Only necessary when the target method is static; else, a target object needs to be specified anyway.

See Also:

setTargetObject(java.lang.Object), setTargetMethod(java.lang.String)

getTargetClass

public Class getTargetClass()

Return the target class on which to call the target method.

setTargetObject

public void setTargetObject(Object targetObject)

Set the target object on which to call the target method. Only necessary when the target method is not static; else, a target class is sufficient.

See Also:

setTargetClass(java.lang.Class), setTargetMethod(java.lang.String)

getTargetObject

public Object getTargetObject()

Return the target object on which to call the target method.

setTargetMethod

public void setTargetMethod(String targetMethod)

Set the name of the method to be invoked. Refers to either a static method or a non-static method, depending on a target object being set.

See Also:

setTargetClass(java.lang.Class), setTargetObject(java.lang.Object)

getTargetMethod

public String getTargetMethod()

Return the name of the method to be invoked.

setStaticMethod

public void setStaticMethod(String staticMethod)

Set a fully qualified static method name to invoke, e.g. "example.MyExampleClass.myExampleMethod". Convenient alternative to specifying targetClass and targetMethod.

See Also:

setTargetClass(java.lang.Class), setTargetMethod(java.lang.String)

setArguments

public void setArguments(Object[] arguments)

Set arguments for the method invocation. If this property is not set, or the Object array is of length 0, a method with no arguments is assumed.

getArguments

public Object[] getArguments()

Retrun the arguments for the method invocation.

prepare

public void prepare()
             throws ClassNotFoundException,
                    NoSuchMethodException

Prepare the specified method. The method can be invoked any number of times afterwards.

Throws:

ClassNotFoundException

NoSuchMethodException

See Also:

getPreparedMethod(), invoke()

resolveClassName

protected Class resolveClassName(String className)
                          throws ClassNotFoundException

Resolve the given class name into a Class.

The default implementations uses ClassUtils.forName, using the thread context class loader.

Parameters:

className - the class name to resolve

Returns:

the resolved Class

Throws:

ClassNotFoundException - if the class name was invalid

findMatchingMethod

protected Method findMatchingMethod()

Find a matching method with the specified name for the specified arguments.

Returns:

a matching method, or null if none

See Also:

getTargetClass(), getTargetMethod(), getArguments()

getPreparedMethod

public Method getPreparedMethod()
                         throws IllegalStateException

Return the prepared Method object that will be invoked.

Can for example be used to determine the return type.

Returns:

the prepared Method object (never null)

Throws:

IllegalStateException - if the invoker hasn't been prepared yet

See Also:

prepare(), invoke()

isPrepared

public boolean isPrepared()

Return whether this invoker has been prepared already, i.e. whether it allows access to getPreparedMethod() already.

invoke

public Object invoke()
              throws InvocationTargetException,
                     IllegalAccessException

Invoke the specified method.

The invoker needs to have been prepared before.

Returns:

the object (possibly null) returned by the method invocation, or null if the method has a void return type

Throws:

InvocationTargetException - if the target method threw an exception

IllegalAccessException - if the target method couldn't be accessed

See Also:

prepare()