Android将应用调试log信息保存在SD卡

package com.sdmc.hotel.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;  
import android.util.Log;
  
/** 
 * log日志统计保存 
 * 会打印i，e，w，不会打印d
 * 每次开启应用，就会把上次的log信息覆盖  
 * @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);  
        }
        Log.i("path", PATH_LOGCAT);///storage/sdcard0/miniGPS
        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 block  
                e.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 + ")\"";//会打印i，e，w，不会打印d   
  
        }  
  
        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((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;  
                }  
  
            }  
  
        }  
  
    }  
  
}  

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

package com.sdmc.hotel.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  
  }  

} 

public class MyApplication extends Application {  
  
    @Override  
    public void onCreate() {  
      
        LogcatHelper.getInstance(this).start();  
    }  

}