如何在此Java程序中读取另一个Java程序的std输出？

BufferedReader#readLine``null

因为您基本上是在忽略此退出指示器并无限循环地循环，所以您得到的只是

null

可能的原因是因为该进程已向错误流输出了一些错误信息，而您没有阅读这些信息。

您应该尝试使用

ProcessBuilder

try {    String[] command = {"java.exe", "mytest.DDD"};    ProcessBuilder pb = new ProcessBuilder(command);    // Use this if the place you are running from (start context)    // is not the same location as the top level of your classes    //pb.directory(new File("pathtoyourclasses"));    pb.redirectErrorStream(true);    Process exec = pb.start();    BufferedReader br = new BufferedReader(new InputStreamReader(exec.getInputStream()));    String text = null;    while ((text = br.readLine()) != null) {        System.out.println(text);    }} catch (IOException exp) {    exp.printStackTrace();}

ps-如果

java.exe