/**     * 保存json到本地     * @param mActivity     * @param filename     * @param content     */    public static File dir = new File(Environment.getExternalStorageDirectory() + "/.Imageloader/json/");    public static void saveToSDCard(Activity mActivity, String filename, String content) {        String en = Environment.getExternalStorageState();        //获取SDCard状态,如果SDCard插入了手机且为非写保护状态          if (en.equals(Environment.MEDIA_MOUNTED)) {            try {                dir.mkdirs(); //create folders where write files                File file = new File(dir, filename);                OutputStream out = new FileOutputStream(file);                out.write(content.getBytes());                out.close();                AppUtils.showToast(mActivity, "保存成功");            } catch (Exception e) {                e.printStackTrace();                AppUtils.showToast(mActivity, "保存失败");            }        } else {            //提示用户SDCard不存在或者为写保护状态              AppUtils.showToast(mActivity, "SDCard不存在或者为写保护状态");        }    }    /**     * 从本地读取json     * @param mActivity     * @param filename     * @param content     */    public static String readTextFile(String filePath) {        StringBuilder sb = new StringBuilder();        try {            File file = new File(dir + "/" + filePath);            InputStream in = null;            in = new FileInputStream(file);            int tempbyte;            while ((tempbyte = in.read()) != -1) {                sb.append((char) tempbyte);            }            in.close();        } catch (Exception e) {            e.printStackTrace();        }        return sb.toString();    }