org.apache.commons.jexl3.internal.introspection
Class MethodExecutor

java.lang.Object
  org.apache.commons.jexl3.internal.introspection.AbstractExecutor.Method
      org.apache.commons.jexl3.internal.introspection.MethodExecutor

All Implemented Interfaces:

JexlMethod

public final class MethodExecutor
extends AbstractExecutor.Method

Specialized executor to invoke a method on an object.

Since:

2.0

TRY_FAILED

public static final Object TRY_FAILED

A marker for invocation failures in tryInvoke.

objectClass

protected final Class<?> objectClass

The class this executor applies to.

method

protected final Method method

Method to be executed.

discover

public static MethodExecutor discover(Introspector is,
                                      Object obj,
                                      String method,
                                      Object[] args)

Discovers 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)

invoke

public Object invoke(Object o,
                     Object... args)
              throws IllegalAccessException,
                     InvocationTargetException

Description copied from interface: JexlMethod

Invocation method, called when the method invocation should be performed and a value returned.

Parameters:

o - the object

args - method parameters.

Returns:

the result

Throws:

IllegalAccessException

InvocationTargetException

tryInvoke

public Object tryInvoke(String name,
                        Object obj,
                        Object... args)

Description copied from interface: JexlMethod

Attempts to reuse this JexlMethod, checking that it is compatible with the actual set of arguments. Related to isCacheable since this method is often used with cached JexlMethod instances.

Parameters:

name - the method name

obj - the object to invoke the method upon

args - the method arguments

Returns:

the result of the method invocation that should be checked by tryFailed to determine if it succeeded or failed.

equals

public boolean equals(Object obj)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

equals

public boolean equals(org.apache.commons.jexl3.internal.introspection.AbstractExecutor arg)

Indicates whether some other executor is equivalent to this one.

Parameters:

arg - the other executor to check

Returns:

true if both executors are equivalent, false otherwise

isAlive

public final boolean isAlive()

Tell whether the executor is alive by looking at the value of the method.

Returns:

boolean Whether the executor is alive.

isCacheable

public boolean isCacheable()

Specifies if this executor is cacheable and able to be reused for this class of object it was returned for.

Returns:

true if can be reused for this class, false if not

getMethod

public final Method getMethod()

Gets the method to be executed or used as a marker.

Returns:

Method The method used by execute in derived classes.

getTargetClass

public final Class<?> getTargetClass()

Gets the object class targeted by this executor.

Returns:

the target object class

getMethodName

public final String getMethodName()

Gets the method name used.

Returns:

method name

tryFailed

public final boolean tryFailed(Object exec)

Checks whether a tryExecute failed or not.

Parameters:

exec - the value returned by tryExecute

Returns:

true if tryExecute failed, false otherwise