org.springframework.batch.item.adapter
Class AbstractMethodInvokingDelegator<T>

java.lang.Object
  org.springframework.batch.item.adapter.AbstractMethodInvokingDelegator<T>

All Implemented Interfaces:

InitializingBean

Direct Known Subclasses:

ItemProcessorAdapter, ItemReaderAdapter, ItemWriterAdapter, MethodInvokingTaskletAdapter, PropertyExtractingDelegatingItemWriter

public abstract class AbstractMethodInvokingDelegator<T>
extends Object
implements InitializingBean

Superclass for delegating classes which dynamically call a custom method of injected object. Provides convenient API for dynamic method invocation shielding subclasses from low-level details and exception handling. Exceptions thrown by a successfully invoked delegate method are re-thrown without wrapping. In case the delegate method throws a Throwable that doesn't subclass Exception it will be wrapped by AbstractMethodInvokingDelegator.InvocationTargetThrowableWrapper.

Author:

Robert Kasanicky

Nested Class Summary

static class

AbstractMethodInvokingDelegator.InvocationTargetThrowableWrapper Used to wrap a Throwable (not an Exception) thrown by a reflectively-invoked delegate.

Constructor Summary

AbstractMethodInvokingDelegator()

Method Summary

void	afterPropertiesSet()
protected T	invokeDelegateMethod() Invoker the target method with arguments set by setArguments(Object[]).
protected T	invokeDelegateMethodWithArgument(Object object) Invokes the target method with given argument.
protected T	invokeDelegateMethodWithArguments(Object[] args) Invokes the target method with given arguments.
void	setArguments(Object[] arguments)
void	setTargetMethod(String targetMethod)
void	setTargetObject(Object targetObject)

Methods inherited from class java.lang.Object

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

Constructor Detail

AbstractMethodInvokingDelegator

public AbstractMethodInvokingDelegator()

Method Detail

invokeDelegateMethod

protected T invokeDelegateMethod()
                          throws Exception

Invoker the target method with arguments set by setArguments(Object[]).

Returns:

object returned by invoked method

Throws:

DynamicMethodInvocationException - if the MethodInvoker used throws exception

Exception

invokeDelegateMethodWithArgument

protected T invokeDelegateMethodWithArgument(Object object)
                                      throws Exception

Invokes the target method with given argument.

Parameters:

object - argument for the target method

Returns:

object returned by target method

Throws:

DynamicMethodInvocationException - if the MethodInvoker used throws exception

Exception

invokeDelegateMethodWithArguments

protected T invokeDelegateMethodWithArguments(Object[] args)
                                       throws Exception

Invokes the target method with given arguments.

Parameters:

args - arguments for the invoked method

Returns:

object returned by invoked method

Throws:

DynamicMethodInvocationException - if the MethodInvoker used throws exception

Exception

afterPropertiesSet

public void afterPropertiesSet()
                        throws Exception

Specified by:

afterPropertiesSet in interface InitializingBean

Throws:

Exception

setTargetObject

public void setTargetObject(Object targetObject)

Parameters:

targetObject - the delegate - bean id can be used to set this value in Spring configuration

setTargetMethod

public void setTargetMethod(String targetMethod)

Parameters:

targetMethod - name of the method to be invoked on setTargetObject(Object).

setArguments

public void setArguments(Object[] arguments)

Parameters:

arguments - arguments values for the { setTargetMethod(String). These will be used only when the subclass tries to invoke the target method without providing explicit argument values. If arguments are set to not-null value afterPropertiesSet() will check the values are compatible with target method's signature. In case arguments are null (not set) method signature will not be checked and it is assumed correct values will be supplied at runtime.