How correctly produce JSON by RESTful web service?

问题

I am writing a web service the first time. I created a RESTful web service based on Jersey. And I want to produce JSON. What do I need to do to generate the correct JSON type of my web service?

Here's one of my methods:

@GET
@Path("/friends")
@Produces("application/json")
public String getFriends() {
    return "{'friends': ['Michael', 'Tom', 'Daniel', 'John', 'Nick']}";
}

Is it sufficient that I simply point out annotation @Produces("application/json") for my method? Then this method may return any type of object? Or only String? Do I need additional processing or transformation of these objects?

Please help me as a beginner to deal with these issues. Thanks in advance!

回答1:

You can annotate your bean with jaxb annotations.

  @XmlRootElement
  public class MyJaxbBean {
    public String name;
    public int age;

    public MyJaxbBean() {} // JAXB needs this

    public MyJaxbBean(String name, int age) {
      this.name = name;
      this.age = age;
    }
  }

and then your method would look like this:

   @GET @Produces("application/json")
   public MyJaxbBean getMyBean() {
      return new MyJaxbBean("Agamemnon", 32);
   }

There is a chapter in the latest documentation that deals with this:

https://jersey.java.net/documentation/latest/user-guide.html#json

回答2:

You could use a package like org.json http://www.json.org/java/

Because you will need to use JSONObjects more often.

There you can easily create JSONObjects and put some values in it:

 JSONObject json = new JSONObject();
 JSONArray array=new JSONArray();
    array.put("1");
    array.put("2");
    json.put("friends", array);

    System.out.println(json.toString(2));


    {"friends": [
      "1",
      "2"
    ]}

edit This has the advantage that you can build your responses in different layers and return them as an object

回答3:

@GET
@Path("/friends")
@Produces(MediaType.APPLICATION_JSON)
public String getFriends() {

    // here you can return any bean also it will automatically convert into json 
    return "{'friends': ['Michael', 'Tom', 'Daniel', 'John', 'Nick']}";
}

回答4:

@POST
@Path ("Employee")
@Consumes("application/json")
@Produces("application/json")
public JSONObject postEmployee(JSONObject jsonObject)throws Exception{
    return jsonObject;
}

回答5:

Use this annotation

@RequestMapping(value = "/url", method = RequestMethod.GET, produces = {MediaType.APPLICATION_JSON_VALUE})

来源：https://stackoverflow.com/questions/13594945/how-correctly-produce-json-by-restful-web-service

标签

java

json

web-services

rest

jersey