Question

如何使用Runtime.getRunTime.exec（）发送和接收多个输入。

例如，如果我想运行诸如openSSL之类的东西来生成csr，它会询问诸如州，城市，公用名等内容。

Process p = Runtime.getRuntime().exec(cmd);
OutputStream out = p.getOutputStream();
//print stuff p.getInputStream(); 
//Now i want to send some inputs 
out.write("test".getBytes()); 
//flush and close??? don't know what to do here
//print what ever is returned
//Now i want to send some more inputs 
out.write("test2".getBytes());
//print what ever is returned.. and so on until this is complete

为什么不使用p.getInputStream（）来读取你需要发送的内容使用out.write（）相应地发送数据。

Process p = Runtime.getRuntime().exec(cmd);
OutputStream out = p.getOutputStream();
//print stuff p.getInputStream();
out.write("test".getBytes()); 
out.close(); //if i don't close, it will just sit there 
//print stuff p.getInputStream();
out.write("test".getBytes()); // I can no longer write at this point, maybe because the outputstream was closed?

Answer 1

为什么不使用p.getInputStream().read()来阅读使用out.write()相应发送数据时需要发送的内容。

以下是一个示例：http://www.rgagnon.com/javadetails/java-0014.html

String line;
OutputStream stdin = null;
InputStream stderr = null;
InputStream stdout = null;

  // launch EXE and grab stdin/stdout and stderr
  Process process = Runtime.getRuntime ().exec ("/folder/exec.exe");
  stdin = process.getOutputStream ();
  stderr = process.getErrorStream ();
  stdout = process.getInputStream ();

  // "write" the parms into stdin
  line = "param1" + "\n";
  stdin.write(line.getBytes() );
  stdin.flush();

  line = "param2" + "\n";
  stdin.write(line.getBytes() );
  stdin.flush();

  line = "param3" + "\n";
  stdin.write(line.getBytes() );
  stdin.flush();

  stdin.close();

  // clean up if any output in stdout
  BufferedReader brCleanUp =
    new BufferedReader (new InputStreamReader (stdout));
  while ((line = brCleanUp.readLine ()) != null) {
    //System.out.println ("[Stdout] " + line);
  }
  brCleanUp.close();

  // clean up if any output in stderr
  brCleanUp =
    new BufferedReader (new InputStreamReader (stderr));
  while ((line = brCleanUp.readLine ()) != null) {
    //System.out.println ("[Stderr] " + line);
  }
  brCleanUp.close();

使用java的交互式命令Runtime.getRunTime.exec（）

1 个答案: