Android--保存logcat到文件

     有时候程序出现异常停止，而logcat 的相关信息很快会被冲掉，因而不能够及时的获取异常信息。所以，借鉴别人的代码，写一个工具类，将相关logcat信息及时的保存到文件。

工具类代码:

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;

 

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(); 

    }

     

    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 + "/";

    }

     

    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(); 

            } 

   

            /**

             * 

             * log level：*:v , *:d , *:w , *:e , *:f , *:s

             * 

             * Show the current mPID process level of E and W log.

             * 

             * */ 

   

            // cmds = "logcat *:e *:w | grep \"(" + mPID + ")\""; 

            // cmds = "logcat  | grep \"(" + mPID + ")\"";//show log of all level

            // cmds = "logcat -s way";//Print label filtering information

 

            cmds = "logcat *:e *:i | grep \"(" + mPID + ")\""; 

   

        } 

   

        public void stopLogs() { 

            mRunning = false; 

        } 

   

        @Override 

        public 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((simpleDateFormat2.format(new Date()) + "  " + 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; 

                } 

            } 

        } 

    } 

}

 

然后在相应的application 或 activity中加入如下代码：

private void startLogcatManager() {
        String folderPath = null;
        
        if (Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) {// save in SD card first 
            folderPath = Environment.getExternalStorageDirectory().getAbsolutePath() + File.separator + "BDT-Logcat";
        } else {// If the SD card does not exist, save in the directory of application.
 
            folderPath = this.getFilesDir().getAbsolutePath() + File.separator + "BDT-Logcat";  
        }
        
        LogcatFileManager.getInstance().start(folderPath);  
    } 
    
    private void stopLogcatManager() {

        LogcatFileManager.getInstance().stop(); 
    }

在对应application 或 activity 对应onCreate()方法及onTerminate()调用对应接口，代码如下：

@Override
    public void onCreate() {
        super.onCreate();
        startLogcatManager();
}


@Override
    public void onTerminate() {
                stopLogcatManager();
                super.onTerminate();
}