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[操作系统]Android输出Log到文件


前言:开发中遇到mx4这款机型Eclipse联调不上,logcat看不了,需要输出生成文件查看调试信息。网上搜了下,功能很完善了。startService和过滤输出信息需要自己添加设置,另外注意添加权限:

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

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

package com.funcity.funm;import java.io.BufferedReader;import java.io.File;import java.io.FileInputStream;import java.io.FileOutputStream;import java.io.IOException;import java.io.InputStream;import java.io.InputStreamReader;import java.io.OutputStreamWriter;import java.text.ParseException;import java.text.SimpleDateFormat;import java.util.ArrayList;import java.util.Arrays;import java.util.Calendar;import java.util.Comparator;import java.util.Date;import java.util.List;import android.app.AlarmManager;import android.app.PendingIntent;import android.app.Service;import android.content.BroadcastReceiver;import android.content.Context;import android.content.Intent;import android.content.IntentFilter;import android.os.Environment;import android.os.IBinder;import android.os.PowerManager;import android.os.PowerManager.WakeLock;import android.util.Log;/*** 日志服务,日志默认会存储在SDcar里如果没有SDcard会存储在内存中的安装目录下面。* 1.本服务默认在SDcard中每天生成一个日志文件,* 2.如果有SDCard的话会将之前内存中的文件拷贝到SDCard中* 3.如果没有SDCard,在安装目录下只保存当前在写日志* 4.SDcard的装载卸载动作会在步骤2,3中切换* 5.SDcard中的日志文件只保存7天* @author Administrator**/public class LogService extends Service {    private static final String TAG = "LogService";    private static final int MEMORY_LOG_FILE_MAX_SIZE = 10 * 1024 * 1024;            //内存中日志文件最大值,10M    private static final int MEMORY_LOG_FILE_MONITOR_INTERVAL = 10 * 60 * 1000;        //内存中的日志文件大小监控时间间隔,10分钟    private static final int SDCARD_LOG_FILE_SAVE_DAYS = 7;                            //sd卡中日志文件的最多保存天数        private String LOG_PATH_MEMORY_DIR;        //日志文件在内存中的路径(日志文件在安装目录中的路径)    private String LOG_PATH_SDCARD_DIR;        //日志文件在sdcard中的路径    @SuppressWarnings("unused")    private String LOG_SERVICE_LOG_PATH;    //本服务产生的日志,记录日志服务开启失败信息        private final int SDCARD_TYPE = 0;            //当前的日志记录类型为存储在SD卡下面    private final int MEMORY_TYPE = 1;            //当前的日志记录类型为存储在内存中    private int CURR_LOG_TYPE = SDCARD_TYPE;    //当前的日志记录类型        private String CURR_INSTALL_LOG_NAME;    //如果当前的日志写在内存中,记录当前的日志文件名称        private String logServiceLogName = "Log.log";//本服务输出的日志文件名称    private SimpleDateFormat myLogSdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");    private OutputStreamWriter writer;        private SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HHmmss");//日志名称格式        private Process process;        private WakeLock wakeLock;         private SDStateMonitorReceiver sdStateReceiver; //SDcard状态监测    private LogTaskReceiver logTaskReceiver;        /* 是否正在监测日志文件大小;     * 如果当前日志记录在SDcard中则为false     * 如果当前日志记录在内存中则为true*/    private boolean logSizeMoniting = false;               private static String MONITOR_LOG_SIZE_ACTION = "MONITOR_LOG_SIZE";        //日志文件监测action    private static String SWITCH_LOG_FILE_ACTION = "SWITCH_LOG_FILE_ACTION";    //切换日志文件action        @Override    public IBinder onBind(Intent intent) {        return null;    }    @Override    public void onCreate() {        super.onCreate();        Log.v("and_log", "LogService onCreate");        init();        register();        deploySwitchLogFileTask();            new LogCollectorThread().start();    }        private void init(){        LOG_PATH_MEMORY_DIR = getFilesDir().getAbsolutePath() + File.separator + "log";        LOG_SERVICE_LOG_PATH = LOG_PATH_MEMORY_DIR + File.separator + logServiceLogName;        LOG_PATH_SDCARD_DIR = Environment.getExternalStorageDirectory().getAbsolutePath() + File.separator                            +    "mxzg_log" + File.separator + "log";        createLogDir();                /* ******************************************************        try {            writer = new OutputStreamWriter(new FileOutputStream(                    LOG_SERVICE_LOG_PATH, true));        } catch (FileNotFoundException e) {            Log.e(TAG, e.getMessage(), e);        }        * ******************************************************/        PowerManager pm = (PowerManager) getApplicationContext().getSystemService(Context.POWER_SERVICE);        wakeLock = pm.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK, TAG);                CURR_LOG_TYPE = getCurrLogType();        Log.i(TAG, "LogService onCreate");    }        private void register(){        IntentFilter sdCarMonitorFilter = new IntentFilter();        sdCarMonitorFilter.addAction(Intent.ACTION_MEDIA_MOUNTED);        sdCarMonitorFilter.addAction(Intent.ACTION_MEDIA_UNMOUNTED);        sdCarMonitorFilter.addDataScheme("file");        sdStateReceiver = new SDStateMonitorReceiver();        registerReceiver(sdStateReceiver, sdCarMonitorFilter);                IntentFilter logTaskFilter = new IntentFilter();        logTaskFilter.addAction(MONITOR_LOG_SIZE_ACTION);        logTaskFilter.addAction(SWITCH_LOG_FILE_ACTION);        logTaskReceiver = new LogTaskReceiver();        registerReceiver(logTaskReceiver,logTaskFilter);    }               /**     * 获取当前应存储在内存中还是存储在SDCard中     * @return     */    public int getCurrLogType(){        if (!Environment.getExternalStorageState().equals(                Environment.MEDIA_MOUNTED)) {            return MEMORY_TYPE;        }else{            return SDCARD_TYPE;        }    }    /**     * 部署日志切换任务,每天凌晨切换日志文件     */    private void deploySwitchLogFileTask() {        Intent intent = new Intent(SWITCH_LOG_FILE_ACTION);        PendingIntent sender = PendingIntent.getBroadcast(this, 0, intent, 0);        Calendar calendar = Calendar.getInstance();        calendar.add(Calendar.DAY_OF_MONTH, 1);        calendar.set(Calendar.HOUR_OF_DAY, 0);        calendar.set(Calendar.MINUTE, 0);        calendar.set(Calendar.SECOND, 0);        // 部署任务        AlarmManager am = (AlarmManager) getSystemService(ALARM_SERVICE);        am.setRepeating(AlarmManager.RTC_WAKEUP, calendar.getTimeInMillis(), AlarmManager.INTERVAL_DAY, sender);        recordLogServiceLog("deployNextTask succ,next task time is:"+myLogSdf.format(calendar.getTime()));    }    /**     * 日志收集     * 1.清除日志缓存     * 2.杀死应用程序已开启的Logcat进程防止多个进程写入一个日志文件     * 3.开启日志收集进程     * 4.处理日志文件     *  移动 OR 删除     */    class LogCollectorThread extends Thread {                public LogCollectorThread(){            super("LogCollectorThread");            Log.d(TAG, "LogCollectorThread is create");        }                @Override        public void run() {            try {                wakeLock.acquire();    //唤醒手机                                clearLogCache();                                List<String> orgProcessList = getAllProcess();                List<ProcessInfo> processInfoList = getProcessInfoList(orgProcessList);                killLogcatProc(processInfoList);                                createLogCollector();                                Thread.sleep(1000);//休眠,创建文件,然后处理文件,不然该文件还没创建,会影响文件删除                                handleLog();                                wakeLock.release();    //释放            } catch (Exception e) {                e.printStackTrace();                recordLogServiceLog(Log.getStackTraceString(e));            }        }    }        /**     * 每次记录日志之前先清除日志的缓存, 不然会在两个日志文件中记录重复的日志     */    private void clearLogCache() {        Process proc = null;        List<String> commandList = new ArrayList<String>();        commandList.add("logcat");        commandList.add("-c");        try {            proc = Runtime.getRuntime().exec(                    commandList.toArray(new String[commandList.size()]));            StreamConsumer errorGobbler = new StreamConsumer(proc                    .getErrorStream());            StreamConsumer outputGobbler = new StreamConsumer(proc                    .getInputStream());            errorGobbler.start();            outputGobbler.start();            if (proc.waitFor() != 0) {                Log.e(TAG, " clearLogCache proc.waitFor() != 0");                recordLogServiceLog("clearLogCache clearLogCache proc.waitFor() != 0");            }        } catch (Exception e) {            Log.e(TAG, "clearLogCache failed", e);            recordLogServiceLog("clearLogCache failed");        } finally {            try {                proc.destroy();            } catch (Exception e) {                Log.e(TAG, "clearLogCache failed", e);                recordLogServiceLog("clearLogCache failed");            }        }    }    /**     * 关闭由本程序开启的logcat进程:     * 根据用户名称杀死进程(如果是本程序进程开启的Logcat收集进程那么两者的USER一致)     * 如果不关闭会有多个进程读取logcat日志缓存信息写入日志文件     *     * @param allProcList     * @return     */    private void killLogcatProc(List<ProcessInfo> allProcList) {        if(process != null){            process.destroy();        }        String packName = this.getPackageName();        String myUser = getAppUser(packName, allProcList);        /*        recordLogServiceLog("app user is:"+myUser);        recordLogServiceLog("========================");        for (ProcessInfo processInfo : allProcList) {            recordLogServiceLog(processInfo.toString());        }        recordLogServiceLog("========================");        */        for (ProcessInfo processInfo : allProcList) {            if (processInfo.name.toLowerCase().equals("logcat")                    && processInfo.user.equals(myUser)) {                android.os.Process.killProcess(Integer                        .parseInt(processInfo.pid));                //recordLogServiceLog("kill another logcat process success,the process info is:"                //        + processInfo);            }        }    }    /**     * 获取本程序的用户名称     *     * @param packName     * @param allProcList     * @return     */    private String getAppUser(String packName, List<ProcessInfo> allProcList) {        for (ProcessInfo processInfo : allProcList) {            if (processInfo.name.equals(packName)) {                return processInfo.user;            }        }        return null;    }    /**     * 根据ps命令得到的内容获取PID,User,name等信息     *     * @param orgProcessList     * @return     */    private List<ProcessInfo> getProcessInfoList(List<String> orgProcessList) {        List<ProcessInfo> procInfoList = new ArrayList<ProcessInfo>();        for (int i = 1; i < orgProcessList.size(); i++) {            String processInfo = orgProcessList.get(i);            String[] proStr = processInfo.split(" ");            // USER PID PPID VSIZE RSS WCHAN PC NAME            // root 1 0 416 300 c00d4b28 0000cd5c S /init            List<String> orgInfo = new ArrayList<String>();            for (String str : proStr) {                if (!"".equals(str)) {                    orgInfo.add(str);                }            }            if (orgInfo.size() == 9) {                ProcessInfo pInfo = new ProcessInfo();                pInfo.user = orgInfo.get(0);                pInfo.pid = orgInfo.get(1);                pInfo.ppid = orgInfo.get(2);                pInfo.name = orgInfo.get(8);                procInfoList.add(pInfo);            }        }        return procInfoList;    }    /**     * 运行PS命令得到进程信息     *     * @return     *             USER PID PPID VSIZE RSS WCHAN PC NAME     *             root 1 0 416 300 c00d4b28 0000cd5c S /init     */    private List<String> getAllProcess() {        List<String> orgProcList = new ArrayList<String>();        Process proc = null;        try {            proc = Runtime.getRuntime().exec("ps");            StreamConsumer errorConsumer = new StreamConsumer(proc                    .getErrorStream());            StreamConsumer outputConsumer = new StreamConsumer(proc                    .getInputStream(), orgProcList);            errorConsumer.start();            outputConsumer.start();            if (proc.waitFor() != 0) {                Log.e(TAG, "getAllProcess proc.waitFor() != 0");                recordLogServiceLog("getAllProcess proc.waitFor() != 0");            }        } catch (Exception e) {            Log.e(TAG, "getAllProcess failed", e);            recordLogServiceLog("getAllProcess failed");        } finally {            try {                proc.destroy();            } catch (Exception e) {                Log.e(TAG, "getAllProcess failed", e);                recordLogServiceLog("getAllProcess failed");            }        }        return orgProcList;    }        /**     * 开始收集日志信息     */    public void createLogCollector() {        String logFileName = sdf.format(new Date()) + ".log";// 日志文件名称        List<String> commandList = new ArrayList<String>();        commandList.add("logcat");        commandList.add("-f");        //commandList.add(LOG_PATH_INSTALL_DIR + File.separator + logFileName);        commandList.add(getLogPath());        commandList.add("-v");        commandList.add("time");        commandList.add("*:I");        commandList.add("*:D");                //commandList.add("*:E");// 过滤所有的错误信息        // 过滤指定TAG的信息//         commandList.add("MyAPP:V");        // commandList.add("*:S");        try {            process = Runtime.getRuntime().exec(                    commandList.toArray(new String[commandList.size()]));            recordLogServiceLog("start collecting the log,and log name is:"+logFileName);            // process.waitFor();        } catch (Exception e) {            Log.e(TAG, "CollectorThread == >" + e.getMessage(), e);            recordLogServiceLog("CollectorThread == >" + e.getMessage());        }    }        /**     * 根据当前的存储位置得到日志的绝对存储路径     * @return     */    public String getLogPath(){        createLogDir();        String logFileName = sdf.format(new Date()) + ".log";// 日志文件名称        if(CURR_LOG_TYPE == MEMORY_TYPE){            CURR_INSTALL_LOG_NAME = logFileName;            Log.d(TAG, "Log stored in memory, the path is:"+LOG_PATH_MEMORY_DIR + File.separator + logFileName);            return LOG_PATH_MEMORY_DIR + File.separator + logFileName;        }else{            CURR_INSTALL_LOG_NAME = null;            Log.d(TAG, "Log stored in SDcard, the path is:"+LOG_PATH_SDCARD_DIR + File.separator + logFileName);            return LOG_PATH_SDCARD_DIR + File.separator + logFileName;        }    }        /**     * 处理日志文件     * 1.如果日志文件存储位置切换到内存中,删除除了正在写的日志文件     *  并且部署日志大小监控任务,控制日志大小不超过规定值     * 2.如果日志文件存储位置切换到SDCard中,删除7天之前的日志,移     *      动所有存储在内存中的日志到SDCard中,并将之前部署的日志大小     *  监控取消     */    public void handleLog(){        if(CURR_LOG_TYPE == MEMORY_TYPE){            deployLogSizeMonitorTask();            deleteMemoryExpiredLog();        }else{            moveLogfile();            cancelLogSizeMonitorTask();            deleteSDcardExpiredLog();        }    }        /**     * 部署日志大小监控任务     */    private void deployLogSizeMonitorTask() {        if(logSizeMoniting){    //如果当前正在监控着,则不需要继续部署            return;        }        logSizeMoniting = true;        Intent intent = new Intent(MONITOR_LOG_SIZE_ACTION);        PendingIntent sender = PendingIntent.getBroadcast(this, 0, intent, 0);        AlarmManager am = (AlarmManager) getSystemService(ALARM_SERVICE);        am.setRepeating(AlarmManager.RTC_WAKEUP,System.currentTimeMillis(), MEMORY_LOG_FILE_MONITOR_INTERVAL, sender);        Log.d(TAG, "deployLogSizeMonitorTask() succ !");        //recordLogServiceLog("deployLogSizeMonitorTask() succ ,start time is " + calendar.getTime().toLocaleString());    }        /**     * 取消部署日志大小监控任务     */     private void cancelLogSizeMonitorTask() {        logSizeMoniting = false;        AlarmManager am = (AlarmManager) getSystemService(ALARM_SERVICE);        Intent intent = new Intent(MONITOR_LOG_SIZE_ACTION);        PendingIntent sender = PendingIntent.getBroadcast(this, 0, intent, 0);        am.cancel(sender);                Log.d(TAG, "canelLogSizeMonitorTask() succ");    }        /**     * 检查日志文件大小是否超过了规定大小     * 如果超过了重新开启一个日志收集进程     */    private void checkLogSize(){        if(CURR_INSTALL_LOG_NAME != null && !"".equals(CURR_INSTALL_LOG_NAME)){            String path = LOG_PATH_MEMORY_DIR + File.separator + CURR_INSTALL_LOG_NAME;            File file = new File(path);            if(!file.exists()){                return;            }            Log.d(TAG, "checkLog() ==> The size of the log is too big?");            if(file.length() >= MEMORY_LOG_FILE_MAX_SIZE){                Log.d(TAG, "The log's size is too big!");                new LogCollectorThread().start();            }        }    }        /**     * 创建日志目录     */    private void createLogDir() {        File file = new File(LOG_PATH_MEMORY_DIR);        boolean mkOk;        if (!file.isDirectory()) {            mkOk = file.mkdirs();            if (!mkOk) {                mkOk = file.mkdirs();            }        }        /* ************************************        file = new File(LOG_SERVICE_LOG_PATH);        if (!file.exists()) {            try {                mkOk = file.createNewFile();                if (!mkOk) {                    file.createNewFile();                }            } catch (IOException e) {                Log.e(TAG, e.getMessage(), e);            }        }        * ************************************/                if (Environment.getExternalStorageState().equals(                Environment.MEDIA_MOUNTED)) {            file = new File(LOG_PATH_SDCARD_DIR);            if (!file.isDirectory()) {                mkOk = file.mkdirs();                if (!mkOk) {                    recordLogServiceLog("move file failed,dir is not created succ");                    return;                }            }        }    }        /**     * 将日志文件转移到SD卡下面     */    private void moveLogfile() {        if (!Environment.getExternalStorageState().equals(                Environment.MEDIA_MOUNTED)) {            //recordLogServiceLog("move file failed, sd card does not mount");            return;        }        File file = new File(LOG_PATH_SDCARD_DIR);        if (!file.isDirectory()) {            boolean mkOk = file.mkdirs();            if (!mkOk) {                //recordLogServiceLog("move file failed,dir is not created succ");                return;            }        }        file = new File(LOG_PATH_MEMORY_DIR);        if (file.isDirectory()) {            File[] allFiles = file.listFiles();            for (File logFile : allFiles) {                String fileName = logFile.getName();                if (logServiceLogName.equals(fileName)) {                    continue;                }                //String createDateInfo = getFileNameWithoutExtension(fileName);                boolean isSucc = copy(logFile, new File(LOG_PATH_SDCARD_DIR                            + File.separator + fileName));                if (isSucc) {                    logFile.delete();                    //recordLogServiceLog("move file success,log name is:"+fileName);                }            }        }    }    /**     * 删除内存下过期的日志     */    private void deleteSDcardExpiredLog() {        File file = new File(LOG_PATH_SDCARD_DIR);        if (file.isDirectory()) {            File[] allFiles = file.listFiles();            for (File logFile : allFiles) {                String fileName = logFile.getName();                if (logServiceLogName.equals(fileName)) {                    continue;                }                String createDateInfo = getFileNameWithoutExtension(fileName);                if (canDeleteSDLog(createDateInfo)) {                    logFile.delete();                    Log.d(TAG, "delete expired log success,the log path is:"                            + logFile.getAbsolutePath());                }            }        }    }        /**     * 判断sdcard上的日志文件是否可以删除     * @param createDateStr     * @return     */    public boolean canDeleteSDLog(String createDateStr) {        boolean canDel = false;        Calendar calendar = Calendar.getInstance();        calendar.add(Calendar.DAY_OF_MONTH, -1 * SDCARD_LOG_FILE_SAVE_DAYS);//删除7天之前日志        Date expiredDate = calendar.getTime();        try {            Date createDate = sdf.parse(createDateStr);            canDel = createDate.before(expiredDate);        } catch (ParseException e) {            Log.e(TAG, e.getMessage(), e);            canDel = false;        }        return canDel;    }        /**     * 删除内存中的过期日志,删除规则:     * 除了当前的日志和离当前时间最近的日志保存其他的都删除     */    private void deleteMemoryExpiredLog(){        File file = new File(LOG_PATH_MEMORY_DIR);        if (file.isDirectory()) {            File[] allFiles = file.listFiles();            Arrays.sort(allFiles, new FileComparator());            for (int i=0;i<allFiles.length-2;i++) {    //"-2"保存最近的两个日志文件                File _file = allFiles[i];                if (logServiceLogName.equals(_file.getName()) || _file.getName().equals(CURR_INSTALL_LOG_NAME)) {                    continue;                }                _file.delete();                Log.d(TAG, "delete expired log success,the log path is:"+_file.getAbsolutePath());            }        }    }        /**     * 拷贝文件     * @param source     * @param target     * @return     */    private boolean copy(File source, File target) {        FileInputStream in = null;        FileOutputStream out = null;        try {            if(!target.exists()){                boolean createSucc = target.createNewFile();                if(!createSucc){                    return false;                }            }            in = new FileInputStream(source);            out = new FileOutputStream(target);            byte[] buffer = new byte[8*1024];            int count;            while ((count = in.read(buffer)) != -1) {                out.write(buffer, 0, count);            }            return true;        } catch (Exception e) {            e.printStackTrace();            Log.e(TAG, e.getMessage(), e);            recordLogServiceLog("copy file fail");            return false;        } finally{            try {                if(in != null){                    in.close();                }                if(out != null){                    out.close();                }            } catch (IOException e) {                e.printStackTrace();                Log.e(TAG, e.getMessage(), e);                recordLogServiceLog("copy file fail");                return false;            }        }            }    /**     * 记录日志服务的基本信息 防止日志服务有错,在LogCat日志中无法查找     * 此日志名称为Log.log     *     * @param msg     */    private void recordLogServiceLog(String msg) {        if (writer != null) {            try {                Date time = new Date();                writer.write(myLogSdf.format(time) + " : " + msg);                writer.write("\n");                writer.flush();            } catch (IOException e) {                e.printStackTrace();                Log.e(TAG, e.getMessage(), e);            }        }    }        /**     * 去除文件的扩展类型(.log)     * @param fileName     * @return     */    private String getFileNameWithoutExtension(String fileName){        return fileName.substring(0, fileName.indexOf("."));    }    class ProcessInfo {        public String user;        public String pid;        public String ppid;        public String name;        @Override        public String toString() {            String str = "user=" + user + " pid=" + pid + " ppid=" + ppid                    + " name=" + name;            return str;        }    }    class StreamConsumer extends Thread {        InputStream is;        List<String> list;        StreamConsumer(InputStream is) {            this.is = is;        }        StreamConsumer(InputStream is, List<String> list) {            this.is = is;            this.list = list;        }        public void run() {            try {                InputStreamReader isr = new InputStreamReader(is);                BufferedReader br = new BufferedReader(isr);                String line = null;                while ((line = br.readLine()) != null) {                    if (list != null) {                        list.add(line);                    }                }            } catch (IOException ioe) {                ioe.printStackTrace();            }        }    }        /**     * 监控SD卡状态     * @author Administrator     *     */    class SDStateMonitorReceiver extends BroadcastReceiver{        public void onReceive(Context context, Intent intent) {                        if(Intent.ACTION_MEDIA_UNMOUNTED.equals(intent.getAction())){    //存储卡被卸载                if(CURR_LOG_TYPE == SDCARD_TYPE){                    Log.d(TAG, "SDcar is UNMOUNTED");                    CURR_LOG_TYPE = MEMORY_TYPE;                    new LogCollectorThread().start();                }            }else{                                                            //存储卡被挂载                if(CURR_LOG_TYPE == MEMORY_TYPE){                    Log.d(TAG, "SDcar is MOUNTED");                    CURR_LOG_TYPE = SDCARD_TYPE;                    new LogCollectorThread().start();                                    }            }        }    }        /**     * 日志任务接收     * 切换日志,监控日志大小     * @author Administrator     *     */    class LogTaskReceiver extends BroadcastReceiver{        public void onReceive(Context context, Intent intent) {            String action = intent.getAction();            if(SWITCH_LOG_FILE_ACTION.equals(action)){                new LogCollectorThread().start();            }else if(MONITOR_LOG_SIZE_ACTION.equals(action)){                checkLogSize();            }        }    }        class FileComparator implements Comparator<File>{        public int compare(File file1, File file2) {            if(logServiceLogName.equals(file1.getName())){                return -1;            }else if(logServiceLogName.equals(file2.getName())){                return 1;            }                        String createInfo1 = getFileNameWithoutExtension(file1.getName());            String createInfo2 = getFileNameWithoutExtension(file2.getName());                        try {                Date create1 = sdf.parse(createInfo1);                Date create2 = sdf.parse(createInfo2);                if(create1.before(create2)){                    return -1;                }else{                    return 1;                }            } catch (ParseException e) {                return 0;            }        }    }        @Override    public void onDestroy() {        super.onDestroy();        recordLogServiceLog("LogService onDestroy");        if (writer != null) {            try {                writer.close();            } catch (IOException e) {                e.printStackTrace();            }        }        if (process != null) {            process.destroy();        }                unregisterReceiver(sdStateReceiver);        unregisterReceiver(logTaskReceiver);    }}

 转自:Android的log保存到文件上查看