如何使用JSON在JSP和Java控制器之间进行交互？

Question

I'm trying to understand principle of interaction between JSP (with JavaScript) and Java controller using JSON. For example, I have an entity

public class Greeting {
    private final long id;
    private final String content;
    // other part omitted
}

And controller

@Controller
public class GreetingController {

    private final AtomicLong counter = new AtomicLong();

    @RequestMapping("/")
    public String redirect() {
        return "redirect:/greeting";
    }

    @RequestMapping(value = "/greeting")
    @ResponseBody
    public Greeting greeting(@RequestParam("name") String name) {
        return new Greeting(counter.incrementAndGet(), String.format("Hello, %s!", name));
    }
}

How to modify this code to send GET request using JavaSctipt to controller and retrieve JSON answer by JavaScript on jsp page?

I would be appreciated for some examples :) or for some tutorial's links.

Answer 1

You can use jQuery to make a ajax get call to the controller. See https://api.jquery.com/jQuery.ajax/ . You will have to specify the output type as JSON.

eg,

$.ajax({
        type: 'GET',
        url: '<Your URL>',
        cache: false,
        dataType: 'json',
                    // Your input parameters go here
        data: {name: 'someValue'},
        success: function(data, textStatus){                                
        },
        error: function(xhr, textStatus, errorThrown){
        }
    });

The below link explains how to return JSON object from controller: http://www.mkyong.com/spring-mvc/spring-3-mvc-and-json-example/