1/* 2 * Copyright (c) 2007, 2014, 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. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 */ 23 24package test.java.awt.regtesthelpers.process; 25 26import java.io.*; 27 28/** 29 * This class is created to solve interprocess communication problems. 30 * When you need to write a regression test which should verify inter jvm 31 * behavior such as DnD data transfer, Clipboard data transfer, focus 32 * transfer etc., you could use the next scenario: 33 * 34 * 1. Write an implementation for the parent JVM, using applet test. 35 * 2. Write an implementation for the child JVM or native application, using 36 * main() function. 37 * 3. Execute child process using ProcessCommunicator.executeChildProcess() 38 * method. 39 * 4. You can decide whether the test is passed on the basis of 40 * ProcessResults class data. 41 * 42 * Note: The class is not thread safe. You should access its methods only from 43 * the same thread. 44 */ 45 46public class ProcessCommunicator { 47 48 private static final String javaHome = System.getProperty("java.home", ""); 49 private static final String javaPath = javaHome + File.separator + "bin" + 50 File.separator + "java "; 51 private static String command = ""; 52 private static volatile Process process; 53 54 private ProcessCommunicator() {} 55 56 /** 57 * The same as {#link #executeChildProcess(Class,String)} except 58 * the {@code classPathArgument} parameter. The class path 59 * parameter is for the debug purposes 60 * 61 * @param classToExecute is passed to the child JVM 62 * @param classPathArguments class path for the child JVM 63 * @param args arguments that will be passed to the executed class 64 * @return results of the executed {@code Process} 65 */ 66 public static ProcessResults executeChildProcess(final Class classToExecute, 67 final String classPathArguments, final String [] args) 68 { 69 try { 70 String command = buildCommand(classToExecute, classPathArguments, args); 71 process = Runtime.getRuntime().exec(command); 72 return doWaitFor(process); 73 } catch (IOException e) { 74 throw new RuntimeException(e); 75 } 76 } 77 78 /** 79 * Executes child {code Process} 80 * 81 * @param classToExecute class to be executed as a child java process 82 * @param args args to be passed in to the child process 83 * @return results of the executed {@code Process} 84 */ 85 public static ProcessResults executeChildProcess(final Class classToExecute, 86 final String [] args) 87 { 88 return executeChildProcess(classToExecute, System.getProperty("java.class.path"), args); 89 } 90 91 /** 92 * Waits for a process and return its results. 93 * This is a workaround for {@code Process.waitFor()} never returning. 94 * 95 * @return results of the executed {@code Process} 96 */ 97 public static ProcessResults doWaitFor(final Process p) { 98 ProcessResults pres = new ProcessResults(); 99 100 final InputStream in; 101 final InputStream err; 102 103 try { 104 in = p.getInputStream(); 105 err = p.getErrorStream(); 106 107 boolean finished = false; 108 109 while (!finished) { 110 try { 111 while (in.available() > 0) { 112 pres.appendToStdOut((char)in.read()); 113 } 114 while (err.available() > 0) { 115 pres.appendToStdErr((char)err.read()); 116 } 117 // Ask the process for its exitValue. If the process 118 // is not finished, an IllegalThreadStateException 119 // is thrown. If it is finished, we fall through and 120 // the variable finished is set to true. 121 pres.setExitValue(p.exitValue()); 122 finished = true; 123 } 124 catch (IllegalThreadStateException e) { 125 // Process is not finished yet; 126 // Sleep a little to save on CPU cycles 127 Thread.currentThread().sleep(500); 128 } 129 } 130 if (in != null) in.close(); 131 if (err != null) err.close(); 132 } 133 catch (Throwable e) { 134 System.err.println("doWaitFor(): unexpected exception"); 135 e.printStackTrace(); 136 } 137 return pres; 138 } 139 140 /** 141 * Builds command on the basis of the passed class name, 142 * class path and arguments. 143 * 144 * @param classToExecute with class will be executed in the new JVM 145 * @param classPathArguments java class path (only for test purposes) 146 * @param args arguments for the new application. This could be used 147 * to pass some information from the parent to child JVM. 148 * @return command to execute the {@code Process} 149 */ 150 private static String buildCommand(final Class classToExecute, 151 final String classPathArguments, final String [] args) 152 { 153 StringBuilder commandBuilder = new StringBuilder(); 154 commandBuilder.append(javaPath).append(" "); 155 commandBuilder.append("-cp ").append(System.getProperty("test.classes", ".")).append(File.pathSeparatorChar); 156 157 if (classPathArguments.trim().length() > 0) { 158 commandBuilder.append(classPathArguments).append(" "); 159 } 160 161 commandBuilder.append(" "); 162 commandBuilder.append(classToExecute.getName()); 163 for (String argument:args) { 164 commandBuilder.append(" ").append(argument); 165 } 166 command = commandBuilder.toString(); 167 return command; 168 } 169 170 /** 171 * Could be used for the debug purposes. 172 * 173 * @return command that was build to execute the child process 174 */ 175 public static String getExecutionCommand () { 176 return command; 177 } 178 179 /** 180 * Terminates the process created by {@code executeChildProcess} methods. 181 */ 182 public static void destroyProcess() { 183 if (process != null) { 184 if (process.isAlive()) { 185 process.destroy(); 186 } 187 process = null; 188 } 189 } 190} 191