如何在使用时分别收集Standard和Standard？

Question

下面的代码获取所有的输出，无论是stdout还是stderr。

String line = String.format("paty/to/script.py");
CommandLine cmd = CommandLine.parse(line);
DefaultExecutor executor = new DefaultExecutor();
ByteArrayOutputStream stdout = new ByteArrayOutputStream();
PumpStreamHandler psh = new PumpStreamHandler(stdout);
executor.setStreamHandler(psh);
int exitvalue = executor.execute(cmd);
String output = stdout.toString();

我怎样才能把这两条溪流分开？

Answer 1

PumpStreamHandler为stderr接受第二个构造函数参数。只有一个OutputStream的构造函数将同时写入stdout和stderr，正如您所观察到的。

请参阅https://commons.apache.org/proper/commons-exec/apidocs/org/apache/commons/exec/PumpStreamHandler.html

因此，下面的方法应该处理它。

    String line = String.format("paty/to/script.py");
    CommandLine cmd = CommandLine.parse(line);
    DefaultExecutor executor = new DefaultExecutor();
    ByteArrayOutputStream stdout = new ByteArrayOutputStream();
    ByteArrayOutputStream stderr = new ByteArrayOutputStream();
    PumpStreamHandler psh = new PumpStreamHandler(stdout, stderr);
    executor.setStreamHandler(psh);
    int exitvalue = executor.execute(cmd);
    String output = stdout.toString();
    String error = stderr.toString();