计算缓存大小+清除缓存

//ImageLoader的缓存路径需要改动

//String path = Environment.getExternalStorageDirectory().getPath() + "/Application";
  String path = this.getCacheDir().getPath() + "/imageLoader";

//设置界面

private TextView set_clear;   //清理缓存
private TextView set_size;    //缓存大小

//onCreate方法中

//缓存大小
try {
    String totalCacheSize = getTotalCacheSize();
    set_size.setText(totalCacheSize);
} catch (Exception e) {
    e.printStackTrace();
}

//点击监听

case R.id.set_clear:

    clearAllCache(Settings.this);
    String totalCacheSize = null;
    try {
        totalCacheSize = getTotalCacheSize();
    } catch (Exception e) {
        e.printStackTrace();
    }
    Toast.makeText(this, "清除完成", Toast.LENGTH_SHORT).show();
    set_size.setText(totalCacheSize);
    break;

/**
     * 计算app的缓存大小其实计算的是 getCacheDir()这个file和getExternalCacheDir()这个file大小的和
     */
    public String getTotalCacheSize() throws Exception {
        long cacheSize = getFolderSize(this.getCacheDir());
        if (Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) {
            cacheSize += getFolderSize(this.getExternalCacheDir());
        }
//        File cacheDir = StorageUtils.getOwnCacheDirectory(this, "universalimageloader/Cache");
        return getFormatSize(cacheSize);
    }

    /**
     * 计算文件夹的大小
     */
    public static long getFolderSize(File file) throws Exception {
        if (!file.exists()) {
            return 0;
        }
        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;
    }

    /**
     * 格式化得到的总大小 默认是byte,  然后根据传入的大小,自动转化成合适的大小单位
     *
     * @param size
     * @return
     */
    public static String getFormatSize(double size) {
        double kiloByte = size / 1024;
        if (kiloByte < 1) {
            return "0K";
        }
        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";
    }

    /**
     * 清理app的缓存 其实是清除的getCacheDir 和getExternalCacheDir这两个文件
     *
     * @param context
     */
    public static void clearAllCache(Context context) {
        deleteDir(context.getCacheDir());
        if (Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) {
            deleteDir(context.getExternalCacheDir());
        }
    }

    /**
     * 删除一个文件夹
     *
     * @param dir
     * @return
     */
    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();
    }