java - gson怎么判断json中的key是否存在
部分json文件如下：
{
"statuses": [
{
"created_at": "Fri Dec 02 17:05:40 +0800 2016",
"id": 4048283825629844,
"mid": "4048283825629844",
"idstr": "4048283825629844",
"text": "前卫 //@主治医湿:造型有点害怕 //@冷知君:原谅我不懂时尚 //@城南邮局:最后是刘梓晨吧 //@话提:走远了……",
"source_allowclick": 0,
"source_type": 1,
"source": "<a href=\"http://app.weibo.com/t/feed/6e3owN\" rel=\"nofollow\">iPhone 7 Plus</a>",
"favorited": false,
"truncated": false,
"in_reply_to_status_id": "",
"in_reply_to_user_id": "",
"in_reply_to_screen_name": "",
"pic_urls": [],
"geo": null,
"user": {
"id": 5680719858,
"idstr": "5680719858",
"class": 1,
"screen_name": "综艺博主",
我是使用gson来解析的，代码如下：
public class Main {
public static void main(String[] args) throws IOException {
Gson gson = new Gson();
jsonstring abc = gson.fromJson(json,jsonstring.class);
List<statuses> statuses = abc.getStatuses();
for (statuses st : statuses){
System.out.println(st.getUser().getScreen_name());
}
}
}
}
//json最外层的内容
class jsonstring{
private List<statuses> statuses;
private String hasvisible;
public List<com.lizhao.statuses> getStatuses() {
return statuses;
}
public String getHasvisible() {
return hasvisible;
}
}
//包含statuses中的key
class statuses{
private String created_at;
private String text;
private user user;
public com.lizhao.user getUser() {
return user;
}
public String getCreated_at() {
return created_at;
}
public String getText() {
return text;
}
}
//是statuses里边user这个key的内容
class user{
private String id;
private String screen_name;
private String description;
public String getDescription() {
return description;
}
public String getId() {
return id;
}
public String getScreen_name() {
return screen_name;
}
}
存在一种情况是，user这个key不存在。
我应该怎么判断user这个key是否存在呢？
