@RequestMapping different behavior without @ResponseBody

Question

I have a simple controller class exposing two rest endpoints.

Removing the @ResponseBody is giving different behavior for the two endpoints.

If removed from testRest method - output is =

"1..name"
"1..name..name"
"1..name..name..name"

and so on, finally Stackoverflow exception is thrown

If removed from testSimple method - No Exception , output is "Test simple", response to Postman is :-

{
    "timestamp": "2020-06-09T17:20:02.511+0000",
    "status": 404,
    "error": "Not Found",
    "message": "No message available",
    "path": "/testSimple"
}

Code is :-

package com.search.catalog.rest;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.ResponseBody;

@Controller
public class TestController {

    @RequestMapping(value="/test/{id}", method = RequestMethod.GET)
    @ResponseBody
    public String testRest(@PathVariable String id, @RequestParam String name) {

        System.out.println(id + ".." + name);

        return "result is " + id+ ".." + name;
    }



    @RequestMapping(value="/testSimple", method = RequestMethod.GET)
    @ResponseBody
    public String testSimple() {

        System.out.println("Test Simple ");

        return "Test Simple ";
    }
}

replace annotation Controller with annotation RestController, if you don't want to use annotation ResponseBody — YogendraR, Jun 09 '20 at 17:29
@YogendraR - yeah that resolve the issue, however I want to understand the reason of different behaviour — springcloudlearner, Jun 09 '20 at 17:31
@bharatbhushan `@RespnseBody` converts response into Json if its not used then no conversion automatically — muasif80, Jun 09 '20 at 18:00

score 1 · Answer 1 · answered Jun 09 '20 at 20:04

Without @ResponseBodyspring looks for ViewResolver and as you haven't declared any so spring will use default one InternalResourceViewResolver

By calling ../test/1?name="name" you are experiencing Circular view path .i.e try replacing return "result is " + id + ".." + name; with return "result is "; in testRest().

Answer given by @Sotirios Delimanolis will throw more light on Circular view path.

But if you use ../test/1/?name="name" then you will not end up with this issue.

I hope this will help you.

YogendraR · Answer 2 · 2020-06-09T18:11:29.857

-1

You might want to use @RestController instead of @Controller

@RestController from spring docs:

A convenience annotation that is itself annotated with @Controller and @ResponseBody.

When you use @Controller without @ResponseBody, the spring doesn't act like a pure rest end point.

edited Jun 09 '20 at 18:11

answered Jun 09 '20 at 17:49

YogendraR

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1

The view resolver is interesting. Presumably you mean a _view name_. How is that view name then used and how does its use cause a `StackOverflowError`? – Sotirios Delimanolis Jun 09 '20 at 17:55
@SotiriosDelimanolis I'll update my answer with proper explanation – YogendraR Jun 09 '20 at 18:10

@RequestMapping different behavior without @ResponseBody

2 Answers2