执行non-Java processes命令行的工具ExecHelper
在Java程序里执行操作命令行工具类：
public static void main(String[] args) {
try { /*String file = ExecHelper.exec( new String[]{"XXXX"}, "GBK" ).getOutput(); String hello = ExecHelper.execUsingShell( "echo 'Hello World'" ).getOutput();*/ ExecHelper helper = ExecHelper.execUsingShell("java -version", "GBK"); System.out.println(helper.getResult()); } catch (IOException e) { e.printStackTrace(); } }
输出结果：
java version "1.6.0_37" Java(TM) SE Runtime Environment (build 1.6.0_37-b06) Java HotSpot(TM) Client VM (build 20.12-b01, mixed mode, sharing)
ExecHelper代码实现：
package com.yzu.zhang.utils; import java.io.File; import java.io.IOException; import java.io.InputStreamReader; import java.io.Reader; /** * Convenience methods for executing non-Java processes. * @since ostermillerutils 1.06.00 */ public final class ExecHelper { /** * Executes the specified command and arguments in a separate process, and waits for the * process to finish. * @since ostermillerutils 1.06.00 */ public static ExecHelper exec(String[] cmdarray) throws IOException { return new ExecHelper(Runtime.getRuntime().exec(cmdarray), null); } /** * Executes the specified command and arguments in a separate process, and waits for the * process to finish. * @since ostermillerutils 1.06.00 */ public static ExecHelper exec(String[] cmdarray, String[] envp) throws IOException { return new ExecHelper(Runtime.getRuntime().exec(cmdarray, envp), null); } /** * Executes the specified command and arguments in a separate process, and waits for the * process to finish. * @since ostermillerutils 1.06.00 */ public static ExecHelper exec(String[] cmdarray, String[] envp, File dir) throws IOException { return new ExecHelper(Runtime.getRuntime().exec(cmdarray, envp), null); } /** * Executes the specified command and arguments in a separate process, and waits for the * process to finish. * @since ostermillerutils 1.06.00 */ public static ExecHelper exec(String[] cmdarray, String charset) throws IOException { return new ExecHelper(Runtime.getRuntime().exec(cmdarray), charset); } /** * Executes the specified command and arguments in a separate process, and waits for the * process to finish. * @since ostermillerutils 1.06.00 */ public static ExecHelper exec(String[] cmdarray, String[] envp, String charset) throws IOException { return new ExecHelper(Runtime.getRuntime().exec(cmdarray, envp), charset); } /** * Executes the specified command and arguments in a separate process, and waits for the * process to finish. * @since ostermillerutils 1.06.00 */ public static ExecHelper exec(String[] cmdarray, String[] envp, File dir, String charset) throws IOException { return new ExecHelper(Runtime.getRuntime().exec(cmdarray, envp), charset); } /** * Executes the specified command using a shell. On windows uses cmd.exe or command.exe. * On other platforms it uses /bin/sh. * @since ostermillerutils 1.06.00 */ public static ExecHelper execUsingShell(String command) throws IOException { return execUsingShell(command, null); } /** * Executes the specified command using a shell. On windows uses cmd.exe or command.exe. * On other platforms it uses /bin/sh. * @since ostermillerutils 1.06.00 */ public static ExecHelper execUsingShell(String command, String charset) throws IOException { if (command == null) throw new NullPointerException(); String[] cmdarray; String os = System.getProperty("os.name"); if (os.equals("Windows 95") || os.equals("Windows 98") || os.equals("Windows ME")){ cmdarray = new String[]{"command.exe", "/C", command}; } else if (os.startsWith("Windows")){ cmdarray = new String[]{"cmd.exe", "/C", command}; } else { cmdarray = new String[]{"/bin/sh", "-c", command}; } return new ExecHelper(Runtime.getRuntime().exec(cmdarray), charset); } /** * Take a process, record its standard error and standard out streams, wait for it to finish * * @param process process to watch * @throws SecurityException if a security manager exists and its checkExec method doesn't allow creation of a subprocess. * @throws IOException - if an I/O error occurs * @throws NullPointerException - if cmdarray is null * @throws IndexOutOfBoundsException - if cmdarray is an empty array (has length 0). * * @since ostermillerutils 1.06.00 */ private ExecHelper(Process process, String charset) throws IOException { StringBuffer output = new StringBuffer(); StringBuffer error = new StringBuffer(); Reader stdout; Reader stderr; if (charset == null){ // This is one time that the system charset is appropriate, // don't specify a character set. stdout = new InputStreamReader(process.getInputStream()); stderr = new InputStreamReader(process.getErrorStream()); } else { stdout = new InputStreamReader(process.getInputStream(), charset); stderr = new InputStreamReader(process.getErrorStream(), charset); } char[] buffer = new char[1024]; boolean done = false; boolean stdoutclosed = false; boolean stderrclosed = false; while (!done){ boolean readSomething = false; // read from the process's standard output if (!stdoutclosed && stdout.ready()){ readSomething = true; int read = stdout.read(buffer, 0, buffer.length); if (read < 0){ readSomething = true; stdoutclosed = true; } else if (read > 0){ readSomething = true; output.append(buffer, 0, read); } } // read from the process's standard error if (!stderrclosed && stderr.ready()){ int read = stderr.read(buffer, 0, buffer.length); if (read < 0){ readSomething = true; stderrclosed = true; } else if (read > 0){ readSomething = true; error.append(buffer, 0, read); } } // Check the exit status only we haven't read anything, // if something has been read, the process is obviously not dead yet. if (!readSomething){ try { this.status = process.exitValue(); done = true; } catch (IllegalThreadStateException itx){ // Exit status not ready yet. // Give the process a little breathing room. try { Thread.sleep(100); } catch (InterruptedException ix){ process.destroy(); throw new IOException("Interrupted - processes killed"); } } } } this.output = output.toString(); this.error = error.toString(); } /** * The output of the job that ran. * * @since ostermillerutils 1.06.00 */ private String output; /** * Get the output of the job that ran. * * @return Everything the executed process wrote to its standard output as a String. * * @since ostermillerutils 1.06.00 */ public String getOutput(){ return output; } /** * The error output of the job that ran. * * @since ostermillerutils 1.06.00 */ private String error; /** * Get the error output of the job that ran. * * @return Everything the executed process wrote to its standard error as a String. * * @since ostermillerutils 1.06.00 */ public String getError(){ return error; } /** * The status of the job that ran. * * @since ostermillerutils 1.06.00 */ private int status; /** * Get the status of the job that ran. * * @return exit status of the executed process, by convention, the value 0 indicates normal termination. * * @since ostermillerutils 1.06.00 */ public int getStatus(){ return status; } public String getResult(){ if(!StringUtils.isBlank(output, error)){ return output + "\n\n" +error; } if(StringUtils.isNotBlank(output)){ return output; } if(StringUtils.isNotBlank(error)){ return error; } return null; } }
