如何運行使用Java存儲在String變量中的shell腳本？

Question

我需要在Java中執行一個shell腳本。我的shell腳本不在文件中，它實際上存儲在一個String變量中。我從其他應用程序獲取我的shell腳本細節。

我知道如何在Java中執行不同的命令，如下圖所示：

public static void main(final String[] args) throws IOException, InterruptedException { 
    //Build command 
    List<String> commands = new ArrayList<String>(); 
    commands.add("/bin/cat"); 
    //Add arguments 
    commands.add("/home/david/pk.txt"); 
    System.out.println(commands); 

    //Run macro on target 
    ProcessBuilder pb = new ProcessBuilder(commands); 
    pb.directory(new File("/home/david")); 
    pb.redirectErrorStream(true); 
    Process process = pb.start(); 

    //Read output 
    StringBuilder out = new StringBuilder(); 
    BufferedReader br = new BufferedReader(new InputStreamReader(process.getInputStream())); 
    String line = null, previous = null; 
    while ((line = br.readLine()) != null) 
     if (!line.equals(previous)) { 
      previous = line; 
      out.append(line).append('\n'); 
      System.out.println(line); 
     } 

    //Check result 
    if (process.waitFor() == 0) { 
     System.out.println("Success!"); 
     System.exit(0); 
    } 

    //Abnormal termination: Log command parameters and output and throw ExecutionException 
    System.err.println(commands); 
    System.err.println(out.toString()); 
    System.exit(1); 
} 

就我而言，我將有一個JSON字符串變量從我提取劇本的內容腳本信息：

{"script":"#!/bin/bash\n\necho \"Hello World\"\n"} 

以下是我從上面的json中提取腳本內容的代碼，現在我不知道如何執行此腳本並將一些參數傳遞給它。目前，我可以通過任何簡單的字符串參數：

String script = extractScriptValue(path, "script"); // this will give back actual shell script 

// now how can I execute this shell script using the same above program? 
// Also how I can pass some parameters as well to any shell script? 

執行上述腳本後，應打印出Hello World。

Answer 1

您需要先從殼Process，然後把你的腳本的輸入流。以下只是一個概念證明，你需要改變一些東西（像ProcessBuilder創建過程）：

public static void main(String[] args) throws IOException, InterruptedException { 

    // this is your script in a string 
    String script = "#!/bin/bash\n\necho \"Hello World\"\n echo $val"; 

    List<String> commandList = new ArrayList<>(); 
    commandList.add("/bin/bash"); 

    ProcessBuilder builder = new ProcessBuilder(commandList); 
    builder.environment().put("val", "42"); 
    builder.redirectErrorStream(true); 
    Process shell = builder.start(); 

    // Send your script to the input of the shell, something 
    // like doing cat script.sh | bash in the terminal 
    try(OutputStream commands = shell.getOutputStream()) { 
     commands.write(script.getBytes()); 
    } 

    // read the outcome 
    try(BufferedReader reader = new BufferedReader(new InputStreamReader(shell.getInputStream()))) { 
     String line; 
     while((line = reader.readLine()) != null) { 
      System.out.println(line); 
     } 
    } 

    // check the exit code 
    int exitCode = shell.waitFor(); 
    System.out.println("EXIT CODE: " + exitCode); 
}