将Android应用log信息保存到手机本地

在调试android app时，为了方便查看logcat信息，所以选择把log信息存储在本地。在没有wifi的情况下，无法选择无线连接调试，保存log信息到本地也是不错的选择。

代码如下:

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

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;

/**
* Created by elena on 2017/9/4.
*/

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 + "llvisionLog";
} 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 + "llvisionLog";
}
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, "log-"
+ 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 + ")\"";

}

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((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;
}

}

}

}
public  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  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
//        }
}

权限：

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

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

引用：

public class MyApplication extends Application {  

  

    @Override  

    public void onCreate() {  

        // TODO Auto-generated method stub  

        LogcatHelper.getInstance(this).start();  

    }  

}