从运行时进程java捕获错误

问题描述

我正在使用 Runtime.getRuntime().exec 像这样从另一个 Java 应用程序运行 Java 程序

I'm running a Java program from another Java application using Runtime.getRuntime().exec like this

Process p1 = Runtime.getRuntime().exec("javac test.java");
Process p2 = Runtime.getRuntime().exec("java test");

test.java 的内容

The content of the test.java

import java.io.*;
class test
{
 public static void main(String args[])
  {
  Scanner sc = new Scanner(System.in);
  String s = sc.nextLine();
  System.out.println(s);
  }
}

我想处理p2过程的输入、输出和错误流.我确实捕获了 test.java 的输出，但是，我不知道如何处理输出和错误.

I want to handle Input, Output and Error stream of the process p2.I did capture of the output of the test.java, however, I do not know how to handle output and error.

这是我的代码:

try {
    String s = "";
    InputStream istr = p2.getInputStream();
    BufferedReader br = new BufferedReader(new InputStreamReader(istr));
    BufferedReader bre = new BufferedReader
        (new InputStreamReader(p2.getErrorStream()));

    while ((s = br.readLine()) != null) {
        System.out.println(s);
    }
    br.close();
    while ((s = bre.readLine()) != null) {
        System.out.println(s);
    }
    bre.close();
    p2.waitFor();
} catch (IOException ex) {
    ex.printStackTrace();
} catch (Exception err) {
    err.printStackTrace();
}

上面的代码可以很好地捕获test.java 的输出.但是它不显示test.java的错误.

The code above works fine for capturing the output of the test.java. But it does not display error of the test.java.

你能给我一个示例代码来解决这个问题并处理输出流或分享想法吗?提前致谢

Could you please give me a sample code for fixing this problem and handling output stream or share idea? Thanks in advance

推荐答案

我一直使用的解决方案是创建一个单独的线程来读取其中一个流

The solution I've always used is to create a separate thread to read one of the streams

所以，在你的情况下应该是这样的

So, in your case it should be something like

String s = "";
InputStream istr = p2.getInputStream();
BufferedReader br = new BufferedReader(new InputStreamReader(istr));
BufferedReader bre = new BufferedReader
        (new InputStreamReader(p2.getErrorStream()));


new Thread(new Runnable() {
    @Override
    public void run() {
       while ((s = br.readLine()) != null) {
             System.out.println(s);
        }
     }
 }).start();

 new Thread(new Runnable() {
    @Override
    public void run() {
         while ((s = bre.readLine()) != null) {
              System.out.println(s);
          }
     }
  }).start();
// when you are finished close streams

这篇关于从运行时进程java捕获错误的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！