Android中保存Logcat信息到文件

首先要声明权限：<uses-permission Android:name="android.permission.READ_LOGS" /> 
 
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
 
实现工具类LogcatFileManager，代码如下：
 
package com.fangdd.maiyunmanager.logutil; 

import java.io.BufferedReader;
 import java.io.File;
 import java.io.FileNotFoundException;
 import java.io.FileOutputStream;
 import java.io.IOException;
 import java.io.InputStreamReader;
 import java.text.SimpleDateFormat;
 import java.util.Date;
 

import android.content.Context;
 import android.os.Environment;
 

public class LogcatFileManager
 {
    private static LogcatFileManager INSTANCE = null;
    private static String PATH_LOGCAT;
    private LogDumper mLogDumper = null;
    private int mPId;
    private SimpleDateFormat simpleDateFormat1 = new SimpleDateFormat("yyyyMMdd");
    private SimpleDateFormat simpleDateFormat2 = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
 

public static LogcatFileManager getInstance()
    {
        if (INSTANCE == null)
        {
            INSTANCE = new LogcatFileManager();
        }
        return INSTANCE;
    }
 

private LogcatFileManager()
    {
        mPId = android.os.Process.myPid();
    }
 

public void startLogcatManager(Context context)
    {
        String folderPath = null;
        if (Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED))
        {
            folderPath = Environment.getExternalStorageDirectory().getAbsolutePath() + File.separator + "MMF-Logcat";
        }
        else
        {
            folderPath = context.getFilesDir().getAbsolutePath() + File.separator + "MMF-Logcat";
        }
        LogcatFileManager.getInstance().start(folderPath);
    }
 

public void stopLogcatManager()
    {
        LogcatFileManager.getInstance().stop();
    }
 

private void setFolderPath(String folderPath)
    {
        File folder = new File(folderPath);
        if (!folder.exists())
        {
            folder.mkdirs();
        }
        if (!folder.isDirectory())
        {
            throw new IllegalArgumentException("The logcat folder path is not a directory: " + folderPath);
        }
 

PATH_LOGCAT = folderPath.endsWith("/") ? folderPath : folderPath + "/";
        LogUtils.d(PATH_LOGCAT);
    }
 

public void start(String saveDirectoy)
    {
        setFolderPath(saveDirectoy);
        if (mLogDumper == null)
        {
            mLogDumper = new LogDumper(String.valueOf(mPId), PATH_LOGCAT);
        }
        mLogDumper.start();
    }
 

public void stop()
    {
        if (mLogDumper != null)
        {
            mLogDumper.stopLogs();
            mLogDumper = null;
        }
    }
 

private class LogDumper extends Thread
    {
        private Process logcatProc;
        private BufferedReader mReader = null;
        private boolean mRunning = true;
        String cmds = null;
        private String mPID;
        private FileOutputStream out = null;
 

public LogDumper(String pid, String dir)
        {
            mPID = pid;
            try
            {
                out = new FileOutputStream(new File(dir, "logcat-" + simpleDateFormat1.format(new Date()) + ".log"), true);
            }
            catch (FileNotFoundException e)
            {
                e.printStackTrace();
            }