Android将应用log信息保存文件

 【亲测可用，相当不错。】相信大家在做应用调试的时候，不可能时时通过USB线连着电脑去查看log信息，所以，将应用的log信息保存到手机本地就很有必要了，有助我们从这些log信息中提取有用的部分，以解决一些bug，下面我把网上分享的代码中作了一些精简，作为开发者使用，个人觉得没必要通过用户上传给我们，用户上传的不需要这么庞大的log信息，仅仅那部分崩溃的log信息即可，可参考我的另外一篇blog:http://blog.csdn.net/weidi1989/article/details/7927273。

        好了，废话不多说，直接分享封装好的log信息类：LogcatHelper

package com.way.util;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 android.content.Context;import android.os.Environment;/** * log日志统计保存 *  * @author way *  */public class LogcatHelper {private static LogcatHelper INSTANCE = null;private static String PATH_LOGCAT;private LogDumper mLogDumper = null;private int mPId;/** *  * 初始化目录 *  * */public void init(Context context) {if (Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) {// 优先保存到SD卡中PATH_LOGCAT = Environment.getExternalStorageDirectory().getAbsolutePath() + File.separator + "miniGPS";} else {// 如果SD卡不存在，就保存到本应用的目录下PATH_LOGCAT = context.getFilesDir().getAbsolutePath()+ File.separator + "miniGPS";}File file = new File(PATH_LOGCAT);if (!file.exists()) {file.mkdirs();}}public static LogcatHelper getInstance(Context context) {if (INSTANCE == null) {INSTANCE = new LogcatHelper(context);}return INSTANCE;}private LogcatHelper(Context context) {init(context);mPId = android.os.Process.myPid();}public void start() {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, "GPS-"+ MyDate.getFileName() + ".log"));} catch (FileNotFoundException e) {// TODO Auto-generated catch blocke.printStackTrace();}/** *  * 日志等级：*:v , *:d , *:w , *:e , *:f , *:s *  * 显示当前mPID程序的 E和W等级的日志. *  * */// cmds = "logcat *:e *:w | grep \"(" + mPID + ")\"";// cmds = "logcat  | grep \"(" + mPID + ")\"";//打印所有日志信息// cmds = "logcat -s way";//打印标签过滤信息cmds = "logcat *:e *:i | grep \"(" + mPID + ")\"";}public void stopLogs() {mRunning = false;}@Overridepublic void run() {try {logcatProc = Runtime.getRuntime().exec(cmds);mReader = new BufferedReader(new InputStreamReader(logcatProc.getInputStream()), 1024);String line = null;while (mRunning && (line = mReader.readLine()) != null) {if (!mRunning) {break;}if (line.length() == 0) {continue;}if (out != null && line.contains(mPID)) {out.write((MyDate.getDateEN() + "  " + line + "\n").getBytes());}}} catch (IOException e) {e.printStackTrace();} finally {if (logcatProc != null) {logcatProc.destroy();logcatProc = null;}if (mReader != null) {try {mReader.close();mReader = null;} catch (IOException e) {e.printStackTrace();}}if (out != null) {try {out.close();} catch (IOException e) {e.printStackTrace();}out = null;}}}}}

记得加上权限：

    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />    <uses-permission android:name="android.permission.READ_LOGS" />

另外把那个时间的工具类也分享一下：

package com.way.util;import java.text.SimpleDateFormat;import java.util.Date;public class MyDate {public static String getFileName() {SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd");String date = format.format(new Date(System.currentTimeMillis()));return date;// 2012年10月03日 23:41:31}public static String getDateEN() {SimpleDateFormat format1 = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");String date1 = format1.format(new Date(System.currentTimeMillis()));return date1;// 2012-10-03 23:41:31}}