android 清理缓存

我这个比较简单
dialog
private void setDialog() {
/**
* 监听对话框里面的button点击事件
*/
DialogInterface.OnClickListener listener = new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
switch (which) {
case AlertDialog.BUTTON_POSITIVE:// "确认"清理缓存
CacheUtil.clearAllCache(getActivity());
try {
cache_size_tv.setText(CacheUtil.getTotalCacheSize(getActivity()));
} catch (Exception e) {
e.printStackTrace();
}
break;
case AlertDialog.BUTTON_NEGATIVE:// "取消"第二个按钮取消对话框
break;
default:
break;
}
}
};
// 创建退出对话框
AlertDialog isExit = new AlertDialog.Builder(getContext()).create();
// 设置对话框标题
isExit.setTitle("清理缓存");
// 设置对话框消息
isExit.setMessage("确定要清理缓存吗？");
// 添加选择按钮并注册监听
isExit.setButton("确定", listener);
isExit.setButton2("取消", listener);
// 显示对话框
isExit.show();
}

缓存清理类
public class CacheUtil {
/**
* 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);
}

/***
 * 清理所有缓存
 * @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
//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 "0.00K";
}

    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";
}

}