How to send response as JSON in Jersey Rest

问题:

I have Jersey Rest Webservice with server side code as

    @GET
    @Produces({MediaType.APPLICATION_XML, MediaType.APPLICATION_JSON})
    public List<Employee> getEmployees()
    {
        return new EmployeeService().getEmployees();
    }

T I am testing the service from chrome rest client. This works fine with Accept: application/xml ** But when I am requesting this with code Accept: application/json

I am getting the following exception:-

javax.servlet.ServletException:

org.glassfish.jersey.message.internal.MessageBodyProviderNotFoundException: MessageBodyWriter not found for media type=application/json, type=class com.rshekhar.domain.Employee, genericType=class com.rshekhar.domain.Employee.

What is the correct way of doing this.

回答1:

You can use Jersey's built-in Jackson JSON library to automatically serialize JSON from any POJO classes. You just need to add Jackson JSON library to your pom.xml:

    <dependency>
        <groupId>com.sun.jersey</groupId>
        <artifactId>jersey-json</artifactId>
        <version>${jersey.version}</version>
    </dependency>

Also in order to activate the POJO mapping of Jersey, you need to add the following lines in web.xml:

    <init-param>
        <param-name>com.sun.jersey.api.json.POJOMappingFeature</param-name>
        <param-value>true</param-value>
    </init-param>

Then if your class method EmployeeService().getEmployees() returns a list of employees, Jersey will serialize it to something like (JSON array)

{"employees": ["name":"Adam", "name":"Robert", ....]} 

回答2:

Can you provide more details related to jersey setup (entity classes annotations for starters)

Do you use JAXB? Which version of Jersey?

Here is nice starting point for your goal: https://github.com/jasonray/jersey-starterkit/wiki/Serializing-a-POJO-to-xml-or-json-using-JAXB

回答3:

Take a look here and try out the example. It almost exactly the same usecase you have mentioned.

multiple content types in jax-rs