Question

I want to create a REST Jersey Web-Service accepting JSON string as input parameter.

Also I will use post requestand from webmethod I will return one JSON string.

How can I consume this in a HTML page using Ajax post request.
I want to know what all changes I need to make it on web method to accept JSON String.

 public class Hello {

      @POST
     public String sayPlainTextHello() {
      return "Hello Jersey";
      }
   }

Answer 1

Need to break down your requests. First, you want to accept a JSON string. So on your method you need

@Consumes(MediaType.APPLICATION_JSON)

Next, you need to decide what you want your method to obtain. You can obtain a JSON string, as you suggest, in which case your method would look like this:

@Consumes(MediaType.APPLICATION_JSON)
public String sayPlainTextHello(final String input) {

Or alternatively if your JSON string maps to a Java object you could take the object directly:

@Consumes(MediaType.APPLICATION_JSON)
public String sayPlainTextHello(final MyObject input) {

You state that you want to return a JSON string. So you need:

@Produces(MediaType.APPLICATION_JSON)

And then you need to actually return a JSON string:

return "{\"result\": \"Hello world\"}";

So your full method looks something like this:

@PATH("/hello")
@POST
@Consumes(MediaType.APPLICATION_JSON)
@Produces(MediaType.APPLICATION_JSON)
public String sayPlainTextHello(final String input) {
  return "{\"result\": \"Hello world\"}";
}

Regarding using AJAX to send and receive, it would look something like this:

var myData="{\"name\": \"John\"}";
var request = $.ajax({
    url: "/hello",
    type: "post",
    data: myData
});

request.done(function (response, textStatus, jqXHR){
    console.log("Response from server: " + response);
});