Android应用log信息保存到手机本地

一、介绍

有时候用户反馈问题，但是手里没有测试机，可以通过该方法实现吧log保存到本地，之后把日志上传服务器或者发送给我们排查问题。

二、实现

1、具体实现代码

package com.dzh.lognative.log;
import android.content.Context;
import android.os.Environment;
import android.util.Log;
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 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 + "aLog";
        } 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 + "aaLog";
        }
        File file = new File(PATH_LOGCAT);
        Log.i("codedzh","存储位置："+PATH_LOGCAT);
        if (!file.exists()) {
            file.mkdirs();
        }
        Log.i("codedzh","文件是否存在："+new File(PATH_LOGCAT).exists());
    }
    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;
    }
}

2、添加权限

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

    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
        requestPermissions(new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE,Manifest.permission.READ_EXTERNAL_STORAGE},100);
     }

3、初始化

package com.dzh.lognative;

import android.app.Application;

import com.dzh.lognative.log.LogcatHelper;

/**
 * @Description: 描述
 * @Author: dzh
 * @CreateDate: 2021-12-07 23:47
 */
public class LogApplication extends Application {

    @Override
    public void onCreate() {
        super.onCreate();
        // TODO Auto-generated method stub
        LogcatHelper.getInstance(this).start();
    }
}

4、编译版本问题
测试建议使用下面target版本，高版本需要单独适配

android {
    compileSdkVersion 28
    buildToolsVersion "28.0.3"
    defaultConfig {
        applicationId "com.dzh.lognative"
        minSdkVersion 15
        targetSdkVersion 28
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
        }
    }
}