Java Reflection Method Invoke invokeMethod(Object object, String methodName, Object[] params, Object[] result)

Description

Find and invoke the method on the object if it exists.

License

Open Source License

Return

true if method was found and invoked; otherwise, false.

Declaration

public static boolean invokeMethod(Object object, String methodName, Object[] params, Object[] result) 

Method Source Code

//package com.java2s;
/*/*from w w w .ja v a2s.  c om*/
Copyright 2009 Semantic Discovery, Inc. (www.semanticdiscovery.com)
    
This file is part of the Semantic Discovery Toolkit.
    
The Semantic Discovery Toolkit is free software: you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
    
The Semantic Discovery Toolkit is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU Lesser General Public License for more details.
    
You should have received a copy of the GNU Lesser General Public License
along with The Semantic Discovery Toolkit.  If not, see <http://www.gnu.org/licenses/>.
*/

import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;

public class Main {
    /**
     * Find and invoke the method on the object if it exists.
     * <p>
     * If result is an array of size 1, then return the return value from
     * invoking the method in result[0]. Note that if the method returns
     * "void", the result object (result[0]) will be null.
     *
     * @return true if method was found and invoked; otherwise, false.
     */
    public static boolean invokeMethod(Object object, String methodName, Object[] params, Object[] result) {
        if (object == null)
            return false;

        boolean retval = false;

        Method method = null;
        Class<?>[] paramTypes = params == null ? null : new Class<?>[params.length];

        if (params != null) {
            for (int i = 0; i < params.length; ++i) {
                paramTypes[i] = params[i] == null ? null : params[i].getClass();
            }
        }

        final Class<?> theClass = object.getClass();

        try {
            method = theClass.getMethod(methodName, paramTypes);
        } catch (NoSuchMethodException nsme) {
            // just return false
        } catch (SecurityException se) {
            // rethrow
            throw new IllegalArgumentException(theClass.getName() + "." + methodName, se);
        }

        // invoke
        if (method != null) {
            try {
                final Object invocationResult = method.invoke(object, params);
                if (result != null && result.length > 0)
                    result[0] = invocationResult;
                retval = true;
            } catch (IllegalAccessException iae) {
                throw new IllegalArgumentException(theClass.getName() + "." + methodName, iae);
            } catch (InvocationTargetException ite) {
                throw new IllegalArgumentException(theClass.getName() + "." + methodName, ite);
            } catch (ExceptionInInitializerError eiie) {
                throw new IllegalArgumentException(theClass.getName() + "." + methodName, eiie);
            }
        }

        return retval;
    }

    /**
     * Get the class with the given classname;
     */
    public static Class getClass(String classname) {
        Class result = null;

        try {
            result = Class.forName(classname);
        } catch (ClassNotFoundException e) {
            throw new IllegalArgumentException(e);
        }

        return result;
    }
}

Related

1. invokeMethod(Object object, String methodName, Class[] signature, Object[] parameters)
2. invokeMethod(Object object, String methodName, List argList)
3. invokeMethod(Object object, String methodName, Object arg, Class argType)
4. invokeMethod(Object object, String methodName, Object... parameters)
5. invokeMethod(Object object, String methodName, Object[] args, Class[] parameterTypes)
6. invokeMethod(Object object, String name, Object... arguments)
7. invokeMethod(Object object, String propertyName)
8. invokeMethod(Object objectInstance, String methodToInvoke, Class[] parameterTypes, Object[] instanceParameters)
9. invokeMethod(Object owner, String methodName)