JSonException具有空值

本文介绍了JSonException具有空值的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

解析JSon时遇到很多问题，其中一个值为空值.

I'm having lots of problems when parsing a JSon and one of it's values has null value.

{ "available_from" : "2012-11-05T00:00:00Z", "available_to" : "2012-11-30T00:00:00Z", "category_id" : 2, "created_at" : "2012-11-05T14:53:39Z", ... }

例如，如果"category_id"等于null，则解析器会出现异常.我该怎么解决?

For example if "category_id" equals null I get an exception on my parser. What can I do to solve it?

希望我已经自我解释了.

Hope I've explained myself..

推荐答案

在尝试从JSONObject获取值之前，您需要检查它是否具有键以及该值是否不是"null".

Before trying to get a value from the JSONObject you need to check if it has the key and if the value is not "null".

每次您尝试访问某个键时都添加此If语句:

Add this If statement every time you try to access a certain key:

JSONObject jsonObject = new JSONObject(str); if(jsonObject.has("category_id")&&!jsonObject.isNull("category_id")){ String s = jsonObject.getString("category_id"); }