简单的日志保存工具类

public class LogUtil {
    private final static Boolean ENABLE = true;
    private final static Boolean NEED_SAVE = true;
    private final static String PATH = Environment.getExternalStorageDirectory().getPath() + "/MyLog//";

    public static void d(String tag, String info) {
        if (ENABLE) {
            Log.d(tag, info);
            save(tag, info);
        }
    }

    public static void e(String tag, String info) {
        if (ENABLE) {
            Log.e(tag, info);
            save(tag, info);
        }
    }

    public static void save(String tag, String info) {
        if (!NEED_SAVE) {
            return;
        }
        SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        makeRootDirectory(PATH);
        String filename = Datetimeutil.date() + ".txt";
        String filePath = PATH + filename;
        String strContent = simpleDateFormat.format(System.currentTimeMillis()) + ":" + tag + ":" + info + "\r\n";
        try {
            File file = new File(filePath);
            if (!file.exists()) {
                file.getParentFile().mkdirs();
                file.createNewFile();
            }
            RandomAccessFile raf = new RandomAccessFile(file, "rwd");
            raf.seek(file.length());
            raf.write(strContent.getBytes());
            raf.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    private static void makeRootDirectory(String filePath) {
        File file = null;
        try {
            file = new File(filePath);
            if (!file.exists()) {
                file.mkdir();
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

定时删除工具类,删除30天以前的

 public static void removeFileByTime(String dirPath) {
        //获取目录下所有文件
        List<File> allFile = getDirAllFile(new File(dirPath));
        SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm");
        //获取当前时间
        Date end = new Date(System.currentTimeMillis());
        try {
            end = dateFormat.parse(dateFormat.format(new Date(System.currentTimeMillis())));
        } catch (Exception e){
            e.printStackTrace();
        }
        for (File file : allFile) {//ComDef
            try {
                //文件时间减去当前时间
                Date start = dateFormat.parse(dateFormat.format(new Date(file.lastModified())));
                long diff = end.getTime() - start.getTime();//这样得到的差值是微秒级别
                long days = diff / (1000 * 60 * 60 * 24);
                if(30 <= days){
                    deleteFile2(file);
                }

            } catch (Exception e){
                e.printStackTrace();
            }
        }
    }

    //删除文件夹及文件夹下所有文件
    public static void deleteFile2(File file) {
        if (file.isDirectory()) {
            File[] files = file.listFiles();
            for (int i = 0; i < files.length; i++) {
                File f = files[i];
                deleteFile2(f);
            }
            file.delete();
        } else if (file.exists()) {
            file.delete();
        }
    }

    //获取指定目录下一级文件
    public static List<File> getDirAllFile(File file) {
        List<File> fileList = new ArrayList<>();
        File[] fileArray = file.listFiles();
        if(fileArray == null)
            return fileList;
        for (File f : fileArray) {
            fileList.add(f);
        }
        fileSortByTime(fileList);
        return fileList;
    }

    //对文件进行时间排序
    public static void fileSortByTime(List<File> fileList) {
        Collections.sort(fileList, new Comparator<File>() {
            public int compare(File p1, File p2) {
                if (p1.lastModified() < p2.lastModified()) {
                    return -1;
                }
                return 1;
            }
        });
    }

自定义Constants接口保存一些常用的常量

  String INTENT_ALARM_LOG = "delete_log";

如果想要定时删除需要用到闹钟广播,每天上午十点删除如下,可以在MainActivity的onCreate()下调用下面的代码

  AlarmManager am = (AlarmManager) getSystemService(ALARM_SERVICE);
        Calendar calendar = Calendar.getInstance();
        calendar.set(Calendar.HOUR_OF_DAY, 10);
        calendar.set(Calendar.MINUTE, 0);
        calendar.set(Calendar.SECOND, 0);
        Intent intent = new Intent(Constants.INTENT_ALARM_LOG);
        PendingIntent pi = PendingIntent.getBroadcast(this, 0, intent, 0);
        am.setRepeating(AlarmManager.RTC_WAKEUP, calendar.getTimeInMillis(), 1000 * 60 * 60 * 24, pi);

然后写一个广播接收类AlarmReceiver ,再静态注册

public class AlarmReceiver extends BroadcastReceiver {
    @Override
    public void onReceive(Context context, Intent intent) {
        String action = intent.getAction();
        if (action.equals(Constants.INTENT_ALARM_LOG)) {
            new Thread(new Runnable() {
                @Override
                public void run() {
                    FileUtils.removeFileByTime(LogUtils.PATH);
                }
            }).start();

        }
    }
}

静态注册

  <receiver android:name=".view.receiver.AlarmReceiver">
            <intent-filter>
                <action android:name="delete_log"/>
            </intent-filter>
        </receiver>