Get a given method, and invoke it

        
/*
 * Copyright (c) Ian F. Darwin, http://www.darwinsys.com/, 1996-2002.
 * All rights reserved. Software written by Ian F. Darwin and others.
 * $Id: LICENSE,v 1.8 2004/02/09 03:33:38 ian Exp $
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS''
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 * 
 * Java, the Duke mascot, and all variants of Sun's Java "steaming coffee
 * cup" logo are trademarks of Sun Microsystems. Sun's, and James Gosling's,
 * pioneering role in inventing and promulgating (and standardizing) the Java 
 * language and environment is gratefully acknowledged.
 * 
 * The pioneering role of Dennis Ritchie and Bjarne Stroustrup, of AT&T, for
 * inventing predecessor languages C and C++ is also gratefully acknowledged.
 */

import java.lang.reflect.Method;

/**
 * This class is just here to give us something to work on, with a println()
 * call that will prove we got here.
 */
class X {
  public void work(String s) {
    System.out.println("Working on \"" + s + "\"");
  }
}

/**
 * Get a given method, and invoke it.
 * 
 * @author Ian F. Darwin, http://www.darwinsys.com/
 * @version $Id: GetMethod.java,v 1.3 2004/02/09 03:33:51 ian Exp $
 */

public class GetMethod {

  public static void main(String[] argv) {
    try {
      Class clX = X.class; // or Class.forName("X");
      // To find a method we need the array of matching Class types.
      Class[] argTypes = { String.class };

      // Now find a Method object for the given method.
      Method worker = clX.getMethod("work", argTypes);

      // To INVOKE the method, we need its actual arguments, as an array.
      Object[] theData = { "Chocolate Chips" };

      // The obvious last step: invoke the method.
      worker.invoke(new X(), theData);
    } catch (Exception e) {
      System.err.println("Invoke() failed: " + e);
    }
  }
}

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Get a given method, and invoke it : Method « Reflection « Java

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