Here you can find the source of invokeMethod(Method m, Object[] o)
public static Object invokeMethod(Method m, Object[] o) throws IllegalAccessException, IllegalArgumentException, InvocationTargetException
//package com.java2s; /*/* w ww . j a v a 2 s . c o m*/ VisAD system for interactive analysis and visualization of numerical data. Copyright (C) 1996 - 2011 Bill Hibbard, Curtis Rueden, Tom Rink, Dave Glowacki, Steve Emmerson, Tom Whittaker, Don Murray, and Tommy Jasmin. This library is free software; you can redistribute it and/or modify it under the terms of the GNU Library General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This library 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 Library General Public License for more details. You should have received a copy of the GNU Library General Public License along with this library; if not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA */ import java.lang.reflect.*; public class Main { /** attempt to invoke a Method with the given Object arguments, performing static method auto-detection and automatic array compression */ public static Object invokeMethod(Method m, Object[] o) throws IllegalAccessException, IllegalArgumentException, InvocationTargetException { Object obj; Object[] args; Class[] c = m.getParameterTypes(); int num = (o == null) ? 0 : o.length; int len = -1; int a = -1; if (c != null) { len = c.length; for (int i = 0; i < len; i++) { if (c[i].isArray()) a = i; } } if (Modifier.isStatic(m.getModifiers())) { // static method obj = null; if (num > 0) { if (a < 0) { args = new Object[num]; System.arraycopy(o, 0, args, 0, num); } else { // compress some of the arguments into array form args = new Object[len]; if (a > 0) System.arraycopy(o, 0, args, 0, a); Object array = Array.newInstance(c[a].getComponentType(), num - len + 1); System.arraycopy(o, a, array, 0, num - len + 1); args[a] = array; if (a < len - 1) System.arraycopy(o, num - len + a + 1, args, a + 1, len - a - 1); } } else args = null; } else { // object method if (num > 0) obj = o[0]; else { // invalid object method return null; } if (num > 1) { if (a < 0) { args = new Object[num - 1]; System.arraycopy(o, 1, args, 0, num - 1); } else { // compress some of the arguments into array form args = new Object[len]; if (a > 0) System.arraycopy(o, 1, args, 0, a); Object array = Array.newInstance(c[a].getComponentType(), num - len); System.arraycopy(o, a + 1, array, 0, num - len); args[a + 1] = array; if (a < len - 1) System.arraycopy(o, num - len + a + 1, args, a + 1, len - a - 1); } } else args = null; } return m.invoke(obj, args); } }