InvokeReflect.java

/*
 *  This file is part of the Jikes RVM project (http://jikesrvm.org).
 *
 *  This file is licensed to You under the Eclipse Public License (EPL);
 *  You may not use this file except in compliance with the License. You
 *  may obtain a copy of the License at
 *
 *      http://www.opensource.org/licenses/eclipse-1.0.php
 *
 *  See the COPYRIGHT.txt file distributed with this work for information
 *  regarding copyright ownership.
 */
import java.lang.reflect.Method;

class InvokeReflect {

  static String  methodToRun         = "run";
  static String  signatureToPrintOut = "()Z";
  static Class[] noparams            = {};

  public static void main(String[] argv) throws Exception {
    if (argv.length == 0) { printUsage(); return; }

    for (int iArg=0; iArg<argv.length; iArg++) {
      String arg = argv[iArg];
      if (arg.startsWith("-h")) { printUsage(); return; }

      // invoking methodToRun() in the class specified by arg
      System.out.println("**** START OF EXECUTION of " + arg + "." +
                         methodToRun + " " + signatureToPrintOut + " ****.");
      Class  klass = Class.forName(arg);
      Method method = klass.getDeclaredMethod(methodToRun, noparams);
      Object result = method.invoke(null, (Object[])noparams);
      System.out.println("**** RESULT: " + result);
    }
  }

  // self-test
  static boolean run() throws Exception {
    methodToRun         = "sampleRun";
    String[] sampleArgv = {"InvokeReflect", "-h"};
    System.out.println("Running `InvokeReflect InvokeReflect -h'");
    main(sampleArgv);
    return true;
  }

  static boolean sampleRun() {
    System.out.println("This is InvokeReflect.sampleRun()");
    return true;
  }

  static void printUsage() {
    System.out.println("\nUsage:  InvokeReflect className ...\n");
  }
}