org.apache.commons.jexl2.internal

Class MethodExecutor

java.lang.Object

org.apache.commons.jexl2.internal.AbstractExecutor

org.apache.commons.jexl2.internal.AbstractExecutor.Method

org.apache.commons.jexl2.internal.MethodExecutor

All Implemented Interfaces:

JexlMethod

public final class MethodExecutor
extends AbstractExecutor.Method

Specialized executor to invoke a method on an object.

Since:

2.0

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.commons.jexl2.internal.AbstractExecutor.Method

AbstractExecutor.Method.Parameter

Nested classes/interfaces inherited from class org.apache.commons.jexl2.internal.AbstractExecutor

AbstractExecutor.Get, AbstractExecutor.Method, AbstractExecutor.Set

Field Summary

Fields

Modifier and Type	Field and Description
private boolean	isVarArgs Whether this method handles varargs.

Fields inherited from class org.apache.commons.jexl2.internal.AbstractExecutor.Method

key

Fields inherited from class org.apache.commons.jexl2.internal.AbstractExecutor

method, objectClass, TRY_FAILED

Constructor Summary

Constructors

Constructor and Description
MethodExecutor(Introspector is, java.lang.Object obj, java.lang.String name, java.lang.Object[] args) Creates a new instance.

Method Summary

Modifier and Type	Method and Description
private static AbstractExecutor.Method.Parameter	discover(Introspector is, java.lang.Object obj, java.lang.String method, java.lang.Object[] args) Discovers a method for a MethodExecutor.
java.lang.Object	execute(java.lang.Object o, java.lang.Object[] args) Invokes the method to be executed.
protected java.lang.Object[]	handleVarArg(java.lang.Class<?> type, int index, java.lang.Object[] actual) Reassembles arguments if the method is a vararg method.
private static boolean	isVarArgMethod(java.lang.reflect.Method m) Determines if a method can accept a variable number of arguments.
java.lang.Object	tryExecute(java.lang.String name, java.lang.Object obj, java.lang.Object[] args) Tries to reuse this executor, checking that it is compatible with the actual set of arguments.

Methods inherited from class org.apache.commons.jexl2.internal.AbstractExecutor.Method

getReturnType, getTargetProperty, invoke, tryInvoke

Methods inherited from class org.apache.commons.jexl2.internal.AbstractExecutor

equals, equals, getMethod, getMethodName, getTargetClass, hashCode, initMarker, isAlive, isCacheable, makeArgs, tryFailed

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.commons.jexl2.introspection.JexlMethod

isCacheable, tryFailed

Field Detail

isVarArgs

private final boolean isVarArgs

Whether this method handles varargs.

Constructor Detail

MethodExecutor

public MethodExecutor(Introspector is,
                      java.lang.Object obj,
                      java.lang.String name,
                      java.lang.Object[] args)

Creates a new instance.

Parameters:

is - the introspector used to discover the method

obj - the object to find the method in

name - the method name

args - the method arguments

Method Detail

execute

public java.lang.Object execute(java.lang.Object o,
                                java.lang.Object[] args)
                         throws java.lang.IllegalAccessException,
                                java.lang.reflect.InvocationTargetException

Invokes the method to be executed.

Specified by:

execute in class AbstractExecutor.Method

Parameters:

o - the object to invoke the method upon

args - the method arguments

Returns:

the result of the method invocation

Throws:

java.lang.IllegalAccessException - Method is inaccessible.

java.lang.reflect.InvocationTargetException - Method body throws an exception.

tryExecute

public java.lang.Object tryExecute(java.lang.String name,
                                   java.lang.Object obj,
                                   java.lang.Object[] args)

Tries to reuse this executor, checking that it is compatible with the actual set of arguments.

Overrides:

tryExecute in class AbstractExecutor.Method

Parameters:

name - the method name

obj - the object to invoke the method upon

args - the method arguments

Returns:

the result of the method invocation or TRY_FAILED if checking failed.

discover

private static AbstractExecutor.Method.Parameter discover(Introspector is,
                                                          java.lang.Object obj,
                                                          java.lang.String method,
                                                          java.lang.Object[] args)

Discovers a method for a MethodExecutor.

If the object is an array, an attempt will be made to find the method in a List (see ArrayListWrapper)

If the object is a class, an attempt will be made to find the method as a static method of that class.

Parameters:

is - the introspector used to discover the method

obj - the object to introspect

method - the name of the method to find

args - the method arguments

Returns:

a filled up parameter (may contain a null method)

handleVarArg

protected java.lang.Object[] handleVarArg(java.lang.Class<?> type,
                                          int index,
                                          java.lang.Object[] actual)

Reassembles arguments if the method is a vararg method.

Parameters:

type - The vararg class type (aka component type of the expected array arg)

index - The index of the vararg in the method declaration (This will always be one less than the number of expected arguments.)

actual - The actual parameters being passed to this method

Returns:

The actual parameters adjusted for the varargs in order to fit the method declaration.

isVarArgMethod

private static boolean isVarArgMethod(java.lang.reflect.Method m)

Determines if a method can accept a variable number of arguments.

Parameters:

m - a the method to check

Returns:

true if method is vararg, false otherwise