Method of Java calling shell script to solve the problem of parameter transfer and authority

1. java Executes shell

java executes the command or script of shell through the Runtime. getRuntime (). exec () method, and the parameters of the exec () method can be the path of the script or the direct shell command

The code is as follows (this code is problematic. See 2) for the complete code:

 /**
   *  Execute shell
   * @param execCmd  Use commands   Or   Script flag bit 
   * @param para  Pass in parameters 
   */
  private static void execShell(boolean execCmd, String... para) {
    StringBuffer paras = new StringBuffer();
    Arrays.stream(para).forEach(x -> paras.append(x).append(" "));
    try {
      String cmd = "", shpath = "";
      if (execCmd) {
        //  Command mode 
        shpath = "echo";
      } else {
      // Script path 
        shpath = "/Users/yangyibo/Desktop/callShell.sh";
      }
      cmd = shpath + " " + paras.toString();
      Process ps = Runtime.getRuntime().exec(cmd);
      ps.waitFor();
      BufferedReader br = new BufferedReader(new InputStreamReader(ps.getInputStream()));
      StringBuffer sb = new StringBuffer();
      String line;
      while ((line = br.readLine()) != null) {
        sb.append(line).append("\n");
      }
      String result = sb.toString();
      System.out.println(result);
    } catch (Exception e) {
      e.printStackTrace();
    }
  }

2. Problems encountered and solutions

Parameter passing problem, when the parameter string passed contains spaces, the above method will truncate the parameters, and the default is that the parameters only go to spaces. Resolution: Place the shell command or script and parameters in an array, and then pass the array into the exec () method. Permission problem, when we use this. getClass (). getResource ("/callShell. sh"). getPath () to get the script position, the shell script under target is taken, and shell script has no execution permission at this time. Resolution: Before executing the script, give the script execution permission.

The complete code is as follows

 /**
   *  Solved   Parameter contains   Spaces and scripts do not have execution permission 
   * @param scriptPath  Script path 
   * @param para  Array of parameters 
   */
  private void execShell(String scriptPath, String ... para) {
    try {
      String[] cmd = new String[]{scriptPath};
      // In order to solve the problem of containing spaces in parameters, 
      cmd=ArrayUtils.addAll(cmd,para);
      // Resolution script does not have execute permission 
      ProcessBuilder builder = new ProcessBuilder("/bin/chmod", "755",scriptPath);
      Process process = builder.start();
      process.waitFor();
      Process ps = Runtime.getRuntime().exec(cmd);
      ps.waitFor();
      BufferedReader br = new BufferedReader(new InputStreamReader(ps.getInputStream()));
      StringBuffer sb = new StringBuffer();
      String line;
      while ((line = br.readLine()) != null) {
        sb.append(line).append("\n");
      }
      // Execution results 
      String result = sb.toString();
    } catch (Exception e) {
      e.printStackTrace();
    }
  }

Source Location:

https://github.com/527515025/JavaTest/tree/master/src/main/java/com/us/callShell

Reference://www.ofstack.com/article/61529. htm

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