Question

也许它与android有一些联系，但IMO并不多。

    package com.main.app;

import java.io.BufferedReader;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.Scanner;

import android.app.Activity;
import android.app.AlertDialog;
import android.os.Bundle;
import android.widget.TextView;

public class RootPermissionActivity extends Activity {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        try {
            Process p = Runtime.getRuntime().exec("su");
            DataOutputStream outputStream = new DataOutputStream(p.getOutputStream());
            outputStream.writeBytes("touchasd /m\n");

                       //codes below used to get the error output, but get nothing.
            TextView suCommandMessage = (TextView)findViewById(R.id.suCommandMessage);
            BufferedReader d = new BufferedReader(new InputStreamReader(p.getErrorStream()));
              String msg;
              while((msg = d.readLine()) != null) {
                  suCommandMessage.setText(msg);
              }

            outputStream.writeBytes("exit \n");
            p.waitFor();
        } catch(IOException e) {
            new AlertDialog.Builder(this)
                           .setTitle("Exception")
                           .setMessage("IOException: " + e)
                           .setPositiveButton("OK", null)
                           .show();
        } catch(InterruptedException e) {
            new AlertDialog.Builder(this)
               .setTitle("Exception")
               .setMessage("InterruptedException: " + e)
               .setPositiveButton("OK", null)
               .show();
        }
    }
}

首先我创建一个新进程su以获得root权限，它只是一个运行shell命令的子进程，然后我将一些代码写入子进程，一切正常。然后我想获得子进程的错误输出，所以我写了一个错误的命令touchasd /m\n，但我不知道如何获得子进程的错误输出，任何人都可以给我一个手？谢谢。：）

Answer 1

执行以下操作以获取流程的错误流。

BufferedReader stdErr = new BufferedReader(new InputStreamReader(p.getErrorStream()));

我没有看到你的代码块中的注释，似乎上面的行和相关内容在你的代码块中被注释掉了。

如何在java中获取子进程的输出

1 个答案: