com.redhat.rhn.common.util

Class MethodUtil

java.lang.Object

com.redhat.rhn.common.util.MethodUtil

public class MethodUtil
extends java.lang.Object

A simple class that assists with method invocation. We should just use the jakarta-commons MethodUtils class, but that class can't deal with static methods, so it is useless to us.

Method Summary

Modifier and Type	Method and Description
static java.lang.Object	callMethod(java.lang.Object o, java.lang.String methodCalled, java.lang.Object... params) Call the specified method with the specified arguments, converting the argument type if necessary.
static java.lang.Object	getClassFromConfig(java.lang.String className, java.lang.Object... args) Get an instance of a class that can have its classname overridden in our config system.
static java.lang.Object	invokeStaticMethod(java.lang.Class clazz, java.lang.String method, java.lang.Object[] args) Invoke a static method from a class.

Methods inherited from class java.lang.Object

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

Method Detail

invokeStaticMethod

public static java.lang.Object invokeStaticMethod(java.lang.Class clazz,
                                                  java.lang.String method,
                                                  java.lang.Object[] args)
                                           throws java.lang.NoSuchMethodException,
                                                  java.lang.IllegalAccessException,
                                                  java.lang.reflect.InvocationTargetException

Invoke a static method from a class. Note that if more than one method qualifies for calling, eg. more than one method is found with compatible parameters, the actual invocation target is undefined.

Parameters:

clazz - The Class to search for the specified method

method - The method to execute.

args - the Arguments to the method.

Returns:

The result of the called method.

Throws:

java.lang.NoSuchMethodException - If the method can't be found

java.lang.IllegalAccessException - if the method cannot be accessed

java.lang.reflect.InvocationTargetException - if the method throws an exception

callMethod

public static java.lang.Object callMethod(java.lang.Object o,
                                          java.lang.String methodCalled,
                                          java.lang.Object... params)

Call the specified method with the specified arguments, converting the argument type if necessary. Note that if more than one method qualifies for calling, eg. more than one method is found with compatible parameters, the actual invocation target is undefined.

Parameters:

o - The object from which to call the method

methodCalled - The method to call

params - a Collection of the parameters to methodCalled

Returns:

the results of the method of the subclass

getClassFromConfig

public static java.lang.Object getClassFromConfig(java.lang.String className,
                                                  java.lang.Object... args)

Get an instance of a class that can have its classname overridden in our config system. If you want a class to not return an instance of the passed in parameter you need to define a config with that same name. For example: List someList = getClassFromConfig("java.lang.LinkedList"); would return a new LinkedList() object. But if you define a config var with: java.lang.LinkedList = com.redhat.rhn.utilRhnSuperLinkedList you will get an instance of that class. Beware this can cause some weird issues if done improperly.

Parameters:

className - to fetch

args - arguments to the constructor.

Returns:

Object created. will throw exception explosion if you define this incorrectly