weex☞清理缓存

获取通讯录、扫码、打开相册、拍照等操作，都是一个套路，就是创建module，原生实现这些方法，前端调用是时候返回最终的结果。
下面是如何获取缓存并清理缓存。(原生获取部分参考网上代码，有价值的只是返回数据)

定义DataCleanManager

public class DataCleanManager {

    /**
     * 获取缓存大小
     *
     * @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);
    }

    /**
     * 清除缓存
     *
     * @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();
    }

    // 获取文件大小
    //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
    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
     * @return
     */
    public static String getFormatSize(double size) {
        double kiloByte = size / 1024;
        if (kiloByte < 1) {
//            return size + "Byte";
            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() + "K";
        }

        double gigaByte = megaByte / 1024;
        if (gigaByte < 1) {
            BigDecimal result2 = new BigDecimal(Double.toString(megaByte));
            return result2.setScale(2, BigDecimal.ROUND_HALF_UP)
                    .toPlainString() + "M";
        }

        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";
    }
}

创建ClearCashModule

public class ClearCashModule extends WXModule {

    @JSMethod(uiThread = true)
    public void clearAllCache(JSCallback callback) {
        DataCleanManager.clearAllCache(mWXSDKInstance.getContext());
    }


    @JSMethod(uiThread = true)
    public void getAllCache(JSCallback callback) {
        try {
            String cashe = DataCleanManager.getTotalCacheSize(mWXSDKInstance.getContext());
            callback.invoke(cashe);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

配置相应的权限，在WXApplication中加入

   WXSDKEngine.registerModule("clearCash", ClearCashModule.class);

然后就是前端调用

const clearCash= weex.requireModule('clearCash')
...         //在方法中直接使用就行了
            clearCash.getAllCache(res => {
                   ...
                })
            clearCash.clearAllCache()