javacontrollerjson_springMVC的controller层接收前端json数据

1.前端的操作&＃xff1a;

对象接收json数据方式&＃xff1a;将所需要传的数据转化为json数据&＃xff0c;并将这些数据以post方式传到后台的controller层&＃xff0c;然后controller层接收json数据&＃xff0c;并且是以对象的形式进行接收。

这里面是springmvc自动控制将这些数据转化为对象&＃xff0c;不需要辅助包fastjson。

用Map接收json数据&＃xff1a;需要使用fastjson包(前提json含有对象数据)。在看github项目的学习过程中&＃xff0c;发现&＃xff1a;封装的对象中&＃xff0c;可以有map类型&＃xff0c;更加方便地接收参数&＃xff0c;将json数据一一绑定到map映射中&＃xff0c;方便我们对json数据操作哦。

2.代码实现&＃xff1a;

模拟前端传过来的json数据

{"people": {"username": "Tom","password": "123456","sex": "男","address": {"province": "安徽","city": "芜湖","town": "天堑","village": "小岗村"},"phones": [

{"operator": "中国移动","phoneNumber": "12345678901"},

{"operator": "中国联通","phoneNumber": "09876543211"}

]

}

}

Address.java

importlombok.Data;

&＃64;Datapublic classAddress {privateString province;privateString city;privateString town;privateString village;

}

Phone.java

importlombok.Data;

&＃64;Datapublic classPhone {privateString operator;privateString phoneNumber;

}

People.java

importlombok.Data;importjava.util.List;

&＃64;Datapublic classPeople {privateString username;privateString password;privateString sex;privateAddress address;private Listphones;

}

controller类

importcom.alibaba.fastjson.JSON;importcom.alibaba.fastjson.JSONObject;importcom.yyj.demo.pojo.Address;importcom.yyj.demo.pojo.People;importcom.yyj.demo.pojo.Phone;importorg.springframework.web.bind.annotation.RequestBody;importorg.springframework.web.bind.annotation.RequestMapping;importorg.springframework.web.bind.annotation.RestController;importjava.util.ArrayList;importjava.util.HashMap;importjava.util.Map;

&＃64;RestController

&＃64;RequestMapping("/people")public classPersonController {

&＃64;RequestMapping("getPeople")public MapgetPeople(&＃64;RequestBody People people){if(people &＃61;&＃61; null){return null;

}

Map param &＃61; new HashMap();

String s&＃61;people.getPhones().toString();

System.out.println(s);

param.put("people",people);returnparam;

}

&＃64;RequestMapping("getOtherPeople")public Map getOtherPeople(&＃64;RequestBody Mapparams){if(params &＃61;&＃61; null){

System.out.println("系统接收参数错误");return null;

}

Map map &＃61; new HashMap<>();

People people&＃61; newPeople();

people.setUsername(params.get("username").toString());

people.setPassword(params.get("password").toString());

people.setSex(params.get("sex").toString());

people.setAddress(JSON.parseObject(JSONObject.toJSONString(params.get("address")),Address.class));

people.setPhones((ArrayList) params.get("phones"));

map.put("people",people);returnmap;

}

}/*{

"username": "Tom",

"password": "123456",

"sex": "男",

"address": {

"province": "安徽",

"city": "芜湖",

"town": "天堑",

"village": "小岗村"

},

"phones": [{

"operator": "中国移动",

"phoneNumber": "12345678901"

},

{

"operator": "中国联通",

"phoneNumber": "09876543211"

}

]

}*/

3.postman测试结果&＃xff1a;

对象接收方式&＃xff1a;

Map接收json数据

4.第二种方式需要添加alibaba的fastjson依赖

com.alibaba

fastjson

1.2.47

5.第二种实现方式遇到的各种坑&＃xff1a;

使用&＃64;ResquestBody Map接收前端json数据,json数据中有数组&＃xff0c;我们不能用String[]去接收这个数组&＃xff0c;要用ArrayList去接收&＃xff0c;原因如下&＃xff1a;&＃64;RequsetBody会读取request的body数据&＃xff0c;之后会调用MappingJackson2HttpMessageConverter解析数据&＃xff0c;会使用到ObjectMapper,之后this.objectMapper.readValue(inputMessage.getBody(), javaType);javaType是AbstractJackson2HttpMessageConverter中getJavaType优选出来可以解析context的类型.

json数据中有对象数据存在时&＃xff0c;我们不能单纯的去直接用这个对象接收这个数据&＃xff0c;会报错的。报错内容&＃xff1a;java.util.LinkedHashMap cannot be cast to ******我的具体做法如下&＃xff1a;我们可以接收的hashmap转换为json&＃xff0c;然后再次把这个json转换为对应的对象。(如有更好的办法&＃xff0c;还望大佬在评论区告诉我一下)