android 日记log保存到本地简单方法

安卓日常开发中，经常需要打印日记，经常需要把log输入到本地查看，本demo是把日记输出到本地的简单示例：

1.初始化保存路径（实例中为SD卡下： /storage/emulated/0/interprenter）

 /** * 初始化目录 */private 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 + "interprenter";    } 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 + "interprenter";    }    File file = new File(PATH_LOGCAT);    if (!file.exists()) {        file.mkdirs();        LogUtils.e("创建文件夹");    }    LogUtils.e(PATH_LOGCAT);}

2.编写一个线程，用户收集和写入日记

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;            }        }    }}

3.对线程控制，已便达到控制日记的收集情况

    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;    }}

4.使用初始化，最好在application中使用

   LogcatHelper.getInstance(this).start();

5.不要忘记添加读写权限

6.启动设备，运行一段时间后，shell命令进入到文件保存路径下查看log文件

命令：adb shellcd /storage/emulated/0/interprenterls

7.adb命令pull出文件到本地

命令：exit 推出shell模式 adb pull /storage/emulated/0/interprenter/log_2018-11-26.log D:\interprenter便可导出文件

8.完整代码

`package com.cniaomu.interprenter.util;

import android.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;

/**

修改日期修改人任务名称功能或Bug描述
2018/8/16 20:46 MUZI102

*/
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 */private 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 + "interprenter";    } 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 + "interprenter";    }    File file = new File(PATH_LOGCAT);    if (!file.exists()) {        file.mkdirs();        LogUtils.e("创建文件夹");    }    LogUtils.e(PATH_LOGCAT);}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
// }
}
`