REST. Jersey. How to programmatically choose what type to return: JSON or XML?
Solution 1
If your client wants to use a part of the URL to configure the response type, you can use a Servlet filter.
An easy way to implement overriding the representation (media type) could use a URL query parameter:
/resources/todo?format=json
The Servlet filter parses the URL query parameters, and if a format=json is present, replaces or adds the accept header "application/json".
Solution 2
Note: I'm the EclipseLink JAXB (MOXy) lead and a member of the JAXB (JSR-222) expert group.
Can I create one class, annotate it with JAXB annotations(for XML support) and declare in web.xml for JSON (Jackson library) support?
You can always use an Application
class to specify a MessageBodyReader
/MessageBodyWriter
for the JSON binding. I believe Jackson provides an implementation in its jar. Below is an example of an Application
class that specifies MOXy as the JSON provider:
package org.example;
import java.util.*;
import javax.ws.rs.core.Application;
import org.eclipse.persistence.jaxb.rs.MOXyJsonProvider;
public class CustomerApplication extends Application {
@Override
public Set<Class<?>> getClasses() {
HashSet<Class<?>> set = new HashSet<Class<?>>(2);
set.add(MOXyJsonProvider.class);
set.add(CustomerService.class);
return set;
}
}
Or I need to create separately two classes for JSON and XML?
EclipseLink JAXB (MOXy) offers native XML binding and is designed to enable you to use the same object model for both JSON and XML. You can integrate it into your JAX-RS application using the MOXyJsonProvider
class:
How I can programmatically choose what type to return (JSON or XML)?
Server Side
You can specify that your service offers both XML and JSON messages using the @Produces
annotation.
@GET
@Produces({MediaType.APPLICATION_XML, MediaType.APPLICATION_JSON})
@Path("{id}")
public Customer read(@PathParam("id") long id) {
return entityManager.find(Customer.class, id);
}
For More Information
Client Side
You can use the MediaType to indicate the type of message. Below is an example using Jersey client APIs. Note how the URL is the same, just the requested media type is different.
Client client = Client.create();
WebResource resource = client.resource("http://localhost:8080/CustomerService/rest/customers");
// Get XML response as a Customer
Customer customer = resource.path("1")
.accept(MediaType.APPLICATION_XML)
.get(Customer.class);
System.out.println(customer.getLastName() + ", "+ customer.getFirstName());
// Get JSON response as a Customer
Customer customer = resource.path("1")
.accept(MediaType.APPLICATION_JSON)
.get(Customer.class);
System.out.println(customer.getLastName() + ", "+ customer.getFirstName());
For More Information
Solution 3
No need for seperate classes, what you need is seperate methods:
@GET
@Produces({ MediaType.APPLICATION_XML, MediaType.APPLICATION_JSON })
public Todo getXML() {
Todo todo = new Todo();
todo.setSummary("This is my first todo");
todo.setDescription("This is my first todo");
return todo;
}
Then in the client side, when you request for the service, you indicate in what format you want it:
// Get XML
System.out.println(service.path("rest").path("todo").accept(MediaType.TEXT_XML).get(String.class));
// Get XML for application
System.out.println(service.path("rest").path("todo").accept(MediaType.APPLICATION_XML).get(String.class));
// Get JSON for application
System.out.println(service.path("rest").path("todo").accept(MediaType.APPLICATION_JSON).get(String.class));
WelcomeTo
Updated on November 29, 2020Comments
-
WelcomeTo over 3 years
I have 2 questions:
1. Can I create one class, annotate it with JAXB annotations(for XML support) and declare in
web.xml
<init-param> <param-name>com.sun.jersey.api.json.POJOMappingFeature</param-name> <param-value>true</param-value> </init-param>
for JSON (Jackson library) support? Or I need to create separately two classes for JSON and XML?
Or may be exist some more elegant way to cause REST service to return both JSON and XML?
2. How I can programmatically choose what type to return (JSON or XML)?
Thanks.
-
WelcomeTo almost 12 yearsthanks, so I understand I need to sent
accept
header from client to get what type I need. But how I can return neccesary type from server? -
Tomer almost 12 yearsOnce you add the producess annotation, the framework will do it automatically for you based on the client request
-
WelcomeTo almost 12 yearsok ok:) I understand it) But what if I want to return neccesary type depending on some other facts (not on client's
accept
header)? Or in ither words, how to returnxml
if client'saccept
header is JSON? -
Tomer almost 12 yearsI fail to see under what situation is that viable?! In all situation, the client is the one initiating the reequest and the client KNOWS in what format he would like to get the request, what you are suggesting will probably cause the client to hate you :)
-
WelcomeTo almost 12 yearsfor example I want to let client to choose type of response in URL:
rest/get/cars/xml
orrest/get/cars/json
. Then depending onpathParam
return right type of response. -
Tomer almost 12 yearsThats a different question, I'd suggest opening a new discussion
-
WelcomeTo almost 12 yearsthanks, but can I configure response type unsing
Response
object when return from method? -
mjn almost 12 yearsResponse can specify the content type: return Response.ok. (...) .type("application/json").build();
-
Ben about 11 yearsIf you're picky about URLs like I am..., you could use a file extension:
/resources/todo.json
or/resources/todo.xml
-
user2163960 over 5 yearsJersey already supports selection by extension, if you enable it: stackoverflow.com/questions/28369396/… with the ServerProperties.MEDIA_TYPE_MAPPINGS (I know this question is older, just linking the answer you wanted, because google brought me here first for the answer of how to change types based on extension)