How to intercept HttpEntity from json response [duplicate] - json

Question

This question already has answers here:
Spring MVC 3.2 #ResponseBody interceptor
(4 answers)
Closed 8 years ago.
I'm using a Spring setup using the json mapping converters to send POJO classes as json back to the client.
E.g.:
#RequestMapping
#ResponseBody
public User getUser() {
User user = getUser();
return user;
}
This will return e.g. something like to the client:
{ 'username': 'My username', 'lastname': 'My lastname' }
I want to intercept all my controller actions to wrap the json in something like:
{
'status': 200,
'data': { 'username': 'My username', 'lastname': 'My lastname' }
}
What would be the best approach for this?

Answer 1

Simply, you can create a map like this
#RequestMapping(value = "/user")
#ResponseBody
public Map<String, Object> getUser(){
User user = new User();
Map<String, Object> map = new HashMap<String, Object>();
map.put("status", 200);
map.put("data", user);
return map;
}
For common usage, you can create a POJO
public static class ResutInfo{
private int status;
private Object data;
//get set}
then write the controller method
#RequestMapping(value = "/user")
#ResponseBody
public ResutInfo getUser2(){
User user = new User();
ResutInfo resutInfo = new ResutInfo();
resutInfo.setStatus(200);
resutInfo.setData(user);
return resutInfo;
}

Answer 2

I find a possible solution for your question by extends MappingJackson2HttpMessageConverter
public class MyMappingJackson2HttpMessageConverter extends MappingJackson2HttpMessageConverter {
#Override
protected void writeInternal(Object object, HttpOutputMessage outputMessage) throws IOException, HttpMessageNotWritableException {
//outputMessage.getHeaders().add("code", DigestUtils.md5Hex(object.toString()));
Map<String, Object> map = new HashMap<String, Object>();
map.put("status", 200);
map.put("data", object);
super.writeInternal(map, outputMessage); //To change body of overridden methods use File | Settings | File Templates.
}
}
Then add your own conventer bean to spring-mvc config file
<mvc:annotation-driven>
<mvc:message-converters register-defaults="true">
<bean class="com.xxx.utils.MyMappingJackson2HttpMessageConverter">
</bean>
</mvc:message-converters>
</mvc:annotation-driven>
<mvc:default-servlet-handler/>
This method does work for each #ResponseBody handler method.
Note that it changes default Spring action, you should think about it.

Answer 3

You can also do something like this
<mvc:annotation-driven> <!-- this is added for validations to work -->
<mvc:message-converters register-defaults="true">
<ref bean="jsonMessageConverter"/>
</mvc:message-converters>
</mvc:annotation-driven>
<bean id="jsonMessageConverter" class="org.springframework.http.converter.json.MappingJacksonHttpMessageConverter">
<property name="objectMapper" ref="YourDtoWrapper"/>
</bean>
<bean id="YourDtoWrapper" class="com.YourDtoWrapper"/>
inside your YourDtoWrapper class you can do something like this
public void writeValue(JsonGenerator jgen, Object value) throws IOException, JsonGenerationException, JsonMappingException {
SomeDTO<Object> someDto = new SomeDTO<Object>("SUCCESS");//you can use an enum here
someDto.setDto(value);//here dto is a property of someDTO
super.writeValue(jgen, SomeDTO.getAsMap(someDto));
}
this will give u result some thing like this
{
serviceResult: "SUCCESS"
context: null
dto: {
id: 1
firstName: "test"
lastName: "admin"
email: "admin#test.com"
phone: 1234
userName: "admin"
password: null
createdBy: "admin"
createdDate: null
statusId: 1
statusName: "ACTIVE"
organisationId: 1
organisationName: "test"
userTypeId: 1
userTypeName: "ADMIN"
roleIds: [0]
}
}