1 /* 2 * Copyright (c) 2019, 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 26 package sun.tools; 27 28 import java.io.IOException; 29 import java.io.UncheckedIOException; 30 import java.nio.file.Files; 31 import java.nio.file.Paths; 32 import java.util.jar.Attributes; 33 import java.util.jar.JarFile; 34 import java.util.stream.Stream; 35 36 /** 37 * A helper class that retrieves the main class name for 38 * a running Java process using the proc filesystem (procfs) 39 */ 40 public class ProcessHelper implements sun.tools.common.ProcessHelper { 41 42 43 private static final String CMD_PREFIX = "cmd:"; 44 private static final ProcessHelper INSTANCE = new ProcessHelper(); 45 getInstance()46 public static ProcessHelper getInstance() { 47 return INSTANCE; 48 } 49 50 /** 51 * Gets the main class name for the given Java process by parsing the 52 * process command line. If the application was started with the <em>-jar</em> 53 * option this method returns the name of the jar file. If the application 54 * was started with <em>-m</em> or <em>--module</em> option, the method returns 55 * the module name and the main class name. 56 * @param pid - process ID (pid) 57 * @return the main class name or null if the process no longer exists or 58 * was started with a native launcher (e.g. jcmd etc) 59 */ 60 getMainClass(String pid)61 public String getMainClass(String pid) { 62 String cmdLine = getCommandLine(pid); 63 if (cmdLine == null) { 64 return null; 65 } 66 if (cmdLine.startsWith(CMD_PREFIX)) { 67 cmdLine = cmdLine.substring(CMD_PREFIX.length()); 68 } 69 String[] parts = cmdLine.split("\0"); 70 String mainClass = null; 71 72 if(parts.length == 0) { 73 return null; 74 } 75 76 // Check the executable 77 String[] executablePath = parts[0].split("/"); 78 if (executablePath.length > 0) { 79 String binaryName = executablePath[executablePath.length - 1]; 80 if (!"java".equals(binaryName)) { 81 // Skip the process if it is not started with java launcher 82 return null; 83 } 84 } 85 86 // To be consistent with the behavior on other platforms, if -jar, -m, or --module 87 // options are used then just return the value (the path to the jar file or module 88 // name with a main class). Otherwise, the main class name is the first part that 89 // is not a Java option (doesn't start with '-' and is not a classpath or a module 90 // whitespace option). 91 92 for (int i = 1; i < parts.length && mainClass == null; i++) { 93 if (i < parts.length - 1) { 94 if (parts[i].equals("-m") || parts[i].equals("--module") || parts[i].equals("-jar")) { 95 return parts[i + 1]; 96 } 97 } 98 99 if (parts[i].startsWith("--module=")) { 100 return parts[i].substring("--module=".length()); 101 } 102 103 // If this is a classpath or a module whitespace option then skip the next part 104 // (the classpath or the option value itself) 105 if (parts[i].equals("-cp") || parts[i].equals("-classpath") || parts[i].equals("--class-path") || 106 isModuleWhiteSpaceOption(parts[i])) { 107 i++; 108 continue; 109 } 110 // Skip all other Java options 111 if (parts[i].startsWith("-")) { 112 continue; 113 } 114 115 // If it is a source-file mode then return null 116 if (parts[i].endsWith(".java")) { 117 return null; 118 } 119 120 mainClass = parts[i]; 121 } 122 return mainClass; 123 124 } 125 getCommandLine(String pid)126 private static String getCommandLine(String pid) { 127 try (Stream<String> lines = 128 Files.lines(Paths.get("/proc/" + pid + "/cmdline"))) { 129 return lines.findFirst().orElse(null); 130 } catch (IOException | UncheckedIOException e) { 131 return null; 132 } 133 } 134 isModuleWhiteSpaceOption(String option)135 private static boolean isModuleWhiteSpaceOption(String option) { 136 return option.equals("-p") || 137 option.equals("--module-path") || 138 option.equals("--upgrade-module-path") || 139 option.equals("--add-modules") || 140 option.equals("--limit-modules") || 141 option.equals("--add-exports") || 142 option.equals("--add-opens") || 143 option.equals("--add-reads") || 144 option.equals("--patch-module"); 145 } 146 147 } 148 149 150