1 /*
   2  * Copyright (c) 2007, 2017, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation. Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 package org.jemmy.input;
  26 
  27 import java.lang.reflect.InvocationTargetException;
  28 import java.lang.reflect.Constructor;
  29 import java.lang.reflect.Method;
  30 
  31 /**
  32  *
  33  * Allows access to classes by reflection.
  34  *
  35  * @author Alexandre Iline (alexandre.iline@sun.com)
  36  */
  37 public class ClassReference {
  38 
  39     private Class<?> cl;
  40     private Object instance;
  41 
  42     /**
  43      * Constructor.
  44      * @param o Object to work with.
  45      */
  46     public ClassReference(Object o) {
  47         super();
  48         instance = o;
  49         cl = o.getClass();
  50     }
  51 
  52     /**
  53      * Contructor.
  54      * The object created by this constructor can be used
  55      * to access static methods and fields only.
  56      *
  57      * @param className name of class
  58      * @exception ClassNotFoundException
  59      */
  60     public ClassReference(String className)
  61             throws ClassNotFoundException {
  62         super();
  63         cl = Class.forName(className);
  64         instance = null;
  65     }
  66 
  67     /**
  68      * Executes class's <code>main(java.lang.String[])</code> method
  69      * with a zero-length <code>java.lang.String</code> array
  70      * as a parameter.
  71      *
  72      * @exception NoSuchMethodException
  73      * @exception InvocationTargetException
  74      */
  75     public void startApplication()
  76             throws InvocationTargetException, NoSuchMethodException {
  77         String[] params = new String[0];
  78         startApplication(params);
  79     }
  80 
  81     /**
  82      * Executes class's <code>main(java.lang.String[])</code> method.
  83      *
  84      * @param params The <code>java.lang.String</code> array to pass
  85      * to <code>main(java.lang.String[])</code>.
  86      * @exception NoSuchMethodException
  87      * @exception InvocationTargetException
  88      */
  89     public void startApplication(String[] params)
  90             throws InvocationTargetException, NoSuchMethodException {
  91         String[] real_params;
  92         if (params == null) {
  93             real_params = new String[0];
  94         } else {
  95             real_params = params;
  96         }
  97         String[][] methodParams = {real_params};
  98         Class[] classes = {real_params.getClass()};
  99         try {
 100             invokeMethod("main", methodParams, classes);
 101         } catch (IllegalAccessException e) {
 102             e.printStackTrace();
 103         } catch (IllegalStateException e) {
 104             e.printStackTrace();
 105         }
 106     }
 107 
 108     /**
 109      * Locates method by name and parameter types and executes it.
 110      *
 111      * @param method_name Name of method.
 112      * @param params Method parameters.
 113      * @param params_classes Method parameters types.
 114      * @return the return value from an invocation of the Method.<BR>
 115      * If <code>method_name</code> method is void, <code>null</code> is returned.<BR>
 116      * If <code>method_name</code> method returns a primitive type, then
 117      * return wrapper class instance.
 118      * @throws InvocationTargetException when the invoked method throws an exception.
 119      * @throws NoSuchMethodException when the method cannot be found.
 120      * @throws IllegalAccessException when access to the class or method is lacking.
 121      * @throws SecurityException if access to the package or method is denied.
 122      */
 123     public Object invokeMethod(String method_name, Object[] params, Class<?>[] params_classes)
 124             throws InvocationTargetException, NoSuchMethodException, IllegalAccessException {
 125         if (params == null) {
 126             params = new Object[0];
 127         }
 128         if (params_classes == null) {
 129             params_classes = new Class<?>[0];
 130         }
 131         Method method = cl.getMethod(method_name,
 132                 params_classes);
 133         return (method.invoke(instance, params));
 134     }
 135 
 136     /**
 137      * Locates constructor by parameter types and creates an instance.
 138      *
 139      * @param params An array of Method parameters.
 140      * @param params_classes An array of Method parameter types.
 141      * @return a new class instance.
 142      * @throws InvocationTargetException when the invoked constructor throws an exception.
 143      * @throws NoSuchMethodException when the constructor cannot be found.
 144      * @throws IllegalAccessException when access to the class or constructor is lacking.
 145      * @throws InstantiationException when the constructor is for an abstract class.
 146      * @throws SecurityException if access to the package or constructor is denied.
 147      */
 148     public Object newInstance(Object[] params, Class[] params_classes)
 149             throws InvocationTargetException, NoSuchMethodException,
 150             IllegalAccessException, InstantiationException {
 151         if (params == null) {
 152             params = new Object[0];
 153         }
 154         if (params_classes == null) {
 155             params_classes = new Class[0];
 156         }
 157         Constructor constructor = cl.getConstructor(params_classes);
 158         return (constructor.newInstance(params));
 159     }
 160 
 161     /**
 162      * Returns the field value.
 163      * @param field_name The name of the field.
 164      * @return the field value
 165      * @see #setField
 166      * @throws NoSuchFieldException when the field cannot be found.
 167      * @throws IllegalAccessException when access to the class or constructor is lacking.
 168      * @throws SecurityException if access to the package or field is denied.
 169      */
 170     public Object getField(String field_name)
 171             throws NoSuchFieldException, IllegalAccessException {
 172         return (cl.getField(field_name).get(instance));
 173     }
 174 
 175     /**
 176      * Change a field's value.
 177      *
 178      * @param field_name The name of the field.
 179      * @param newValue The fields new value.
 180      * @see #getField
 181      * @throws NoSuchFieldException when the field cannot be found.
 182      * @throws IllegalAccessException when access to the class or constructor is lacking.
 183      * @throws SecurityException if access to the package or field is denied.
 184      */
 185     public void setField(String field_name, Object newValue)
 186             throws NoSuchFieldException, IllegalAccessException {
 187         cl.getField(field_name).set(instance, newValue);
 188     }
 189 
 190     /**
 191      * Returns all superclasses.
 192      * @return an array of superclasses, starting with the reference class
 193      * and ending with <code>java.lang.Object</code>.
 194      */
 195     public Class[] getClasses() {
 196         Class cls = cl;
 197         int count = 0;
 198         do {
 199             count++;
 200             cls = cls.getSuperclass();
 201         } while (cls != null);
 202         Class[] result = new Class[count];
 203         cls = cl;
 204         for (int i = 0; i < count; i++) {
 205             result[i] = cls;
 206             cls = cls.getSuperclass();
 207         }
 208         return (result);
 209     }
 210 }