Android clear cache and optimize memory space

Sometimes it is necessary to clean up some cached data (such as image cache, network data cache, etc.) in the project. Of course, the data stored in SharedPreferences also needs to be cleaned up. Of course, having such a function in the App may improve the performance.

public class CacheDataManager {
    /**
     * 获取整体缓存大小
     * @param context
     * @return
     * @throws Exception
     */
    public static String getTotalCacheSize(Context context) throws Exception {
        long cacheSize = getFolderSize(context.getCacheDir());
        if (Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) {
            cacheSize += getFolderSize(context.getExternalCacheDir());
        }
        return getFormatSize(cacheSize);
    }
    /**
     * 获取文件
     * Context.getExternalFilesDir() --> SDCard/Android/data/你的应用的包名/files/ 目录，一般放一些长时间保存的数据
     * Context.getExternalCacheDir() --> SDCard/Android/data/你的应用包名/cache/目录，一般存放临时缓存数据
     * @param file
     * @return
     * @throws Exception
     */
    public static long getFolderSize(File file) throws Exception {
        long size = 0;
        try {
            File[] fileList = file.listFiles();
            for (int i = 0; i < fileList.length; i++) {
                // 如果下面还有文件
                if (fileList[i].isDirectory()) {
                    size = size + getFolderSize(fileList[i]);
                } else {
                    size = size + fileList[i].length();
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return size;
    }
    /**
     * 格式化单位
     * @param size
     */
    public static String getFormatSize(long size) {
        long kb = size / 1024;
        int m = (int) (kb / 1024);
        int kbs = (int) (kb % 1024);
        return m + "." + kbs + "M";
//        double kiloByte = size / 1024;
//        if (kiloByte < 1) {
//            return size + "Byte";
//        }
//        double megaByte = kiloByte / 1024;
//        if (megaByte < 1) {
//            BigDecimal result1 = new BigDecimal(Double.toString(kiloByte));
//            return result1.setScale(2, BigDecimal.ROUND_HALF_UP).toPlainString() + "KB";
//        }
//        double gigaByte = megaByte / 1024;
//        if (gigaByte < 1) {
//            BigDecimal result2 = new BigDecimal(Double.toString(megaByte));
//            return result2.setScale(2, BigDecimal.ROUND_HALF_UP).toPlainString() + "MB";
//        }
//        double teraBytes = gigaByte / 1024;
//        if (teraBytes < 1) {
//            BigDecimal result3 = new BigDecimal(Double.toString(gigaByte));
//            return result3.setScale(2, BigDecimal.ROUND_HALF_UP).toPlainString() + "GB";
//        }
//        BigDecimal result4 = new BigDecimal(teraBytes);
//        return result4.setScale(2, BigDecimal.ROUND_HALF_UP).toPlainString() + "TB";
    }

    /**
     * 清空方法
     * @param context
     */
    public static void clearAllCache(Context context) {
        deleteDir(context.getCacheDir());
        if (Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) {
            deleteDir(context.getExternalCacheDir());
        }
    }

    private static boolean deleteDir(File dir) {
        if (dir != null && dir.isDirectory()) {
            String[] children = dir.list();
            for (int i = 0; i < children.length; i++) {
                boolean success = deleteDir(new File(dir, children[i]));
                if (!success) {
                    return false;
                }
            }
        }
        return dir.delete();
    }

}

Call directly:

 CacheDataManager.clearAllCache(SettingActivity.this);

 In fact, its cleaning speed is very fast, so making a delay effect will give users a little experience:

    @OnClick(R.id.setting_cleancache)
    void clean() {
        //设置默认的等待效果
        mDlg = new WaitingDlg(SettingActivity.this, "", "", true);
        PromptDialog dialog = new PromptDialog(SettingActivity.this, R.string.prompt, R.string.cleancache_title);
        dialog.showYesNo(new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which) {
                SPUtils.clear();
                mDlg.start();
                new Thread(new clearCache()).start();
                dialog.dismiss();
            }
        });
    }

    private Handler handler = new Handler() {
        public void handleMessage(android.os.Message msg) {
            switch (msg.what) {
                case 0:
                    mDlg.dismiss();
                    Toast.makeText(SettingActivity.this, "清理完成", Toast.LENGTH_SHORT).show();
                    try {
                        cachetext.setText(CacheDataManager.getTotalCacheSize(SettingActivity.this));
                    } catch (Exception e) {
                        e.printStackTrace();
                    }
            }
        }

    };

    class clearCache implements Runnable {
        @Override
        public void run() {
            try {
                CacheDataManager.clearAllCache(SettingActivity.this);
                Thread.sleep(1000);
                if (CacheDataManager.getTotalCacheSize(SettingActivity.this).startsWith("0")) {
                    handler.sendEmptyMessage(0);
                }
            } catch (Exception e) {
                return;
            }
        }
    }