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GET call with request body - request body not accessible at controller

I am trying to do a get call with request body(JSON) as the request parameter list exceeds the limit. I am able to send the request via postman/insomnia and request is reaching till controller without any error. But the "requstBody" is empty at controller. What i am missing here?
#GET
#Path("\path")
#Consumes(APPLICATION_JSON)
#Produces(APPLICATION_JSON)
public Response getResponse(String requestBody) throws IOException { }
When I replaced #GET with #POST, requestBody has value. For GET call do we need to add anything more?

I am trying to do a get call with request body(JSON) as the request parameter list exceeds the limit. I am able to send the request via postman/insomnia and request is reaching till controller without any error. But the "requstBody" is empty at controller. What i am missing here?
One thing you are missing is the fact that the semantics of a request body with GET are not well defined.
RFC 7231, Section 4.3.1:
A payload within a GET request message has no defined semantics; sending a payload body on a GET request might cause some existing implementations to reject the request.

There are two ways for sending parameters in an Http Get method. PathVariable and RequestParam. In this way, sent parameters are visible in the request URL. for example:
www.sampleAddress.com/countries/{parameter1}/get-time?city=someValues
In the above request, parameter1 is a path variable and parameter2 is a request parameter. So an example of a valid URL would be:
www.sampleAddress.com/countries/Germany/get-time?city=berlin
To access these parameters in a java controller, you need to define a specific name for the parameters. For example the following controller will receive this type of requests:
#GetMapping(value = "/countries/{parameter1}/get-time", produces = "application/json; charset=utf-8")
public String getTimeOfCities(
#PathVariable(value = "parameter1") String country,
#RequestParam(value = "city") String city
){
return "the method is not implemented yet";
}
You are able to send RequestBody through a Get request but it is not recommended according to this link.
yes, you can send a body with GET, and no, it is never useful
to do so.
This elaboration in elasticsearch website is nice too:
The HTTP libraries of certain languages (notably JavaScript) don’t allow GET requests to have a request body. In fact, some users are suprised that GET requests are ever allowed to have a body.
The truth is that RFC 7231—the RFC that deals with HTTP semantics and
content—does not define what should happen to a GET request with a
body! As a result, some HTTP servers allow it, and some—especially
caching proxies—don’t.
If you want to use Post method, you are able to have RequestBody too. In the case you want to send data by a post request, an appropriate controller would be like this:
#PostMapping(value = "/countries/{parameter1}/get-time", produces = "application/json; charset=utf-8")
public String getTimeOfCitiesByPost(
#PathVariable(value = "parameter1") String country,
#RequestParam(value = "city") String city,
#RequestBody Object myCustomObject
){
return "the method is not implemented yet";
}
myCustomObject could have any type of data you defined in your code. Note that in this way, you should send request body as a Json string.

put #RequestBody on String requestBody parameter

#RequestMapping("/path/{requestBody}")
public Response getResponse(#PathVariable String requestBody) throws IOException { }

Modifying HTTP response body and message

I need to be able to modify the HTTP response body of the response that I am getting when someone hits my Service API. I tried using ConatinerResponseFilter to modify the body, but I believe it will only modify the headers and not the response body. Can someone tell me how I can modify the HTTP response body ,message and the status?

It could be achieved with a WriterInterceptor:
#Provider
public class CustomWriterInterceptor implements WriterInterceptor {
#Override
public void aroundWriteTo(WriterInterceptorContext context)
throws IOException, WebApplicationException {
OutputStream outputStream = context.getOutputStream();
// Manipulate the HTTP entity using the OutputStream
context.setOutputStream(outputStream);
context.proceed();
}
}
In this answer you will find an example of how to modify a JSON sent in the request payload using Jackson (the same idea can be used to manipulate response payload).

The trick is to use a wrapper because body when read as a stream becomes in accessible
Modify HttpServletRequest body
Check this or just check online for modify body in filter
Note :if u are doing a web service then using frameworks like CXF makes it easy modify

How to create endpoint in Jersey for POST requests with or without body

I have an API created with Jersey
There's currently an endpoint to which users can make POST requests. There is no body required, as all the information is in the url.
#POST
#Path("entries")
#Produces(MEDIATYPE_JSON_AND_XML)
public Response createEntry(){
...
}
A new, empty, entry is created and the id is returned.
Content-Type of the request doesn't matter, as there is no request body data.
Now it should also be possible to set specific fields of the new entry during the request, using FormData. For this request a body is necessary, and the Content-Type must be multipart/form-data.
So I've created a second function:
#POST
#Path("entries")
#Consumes("multipart/form-data");
#Produces(MEDIATYPE_JSON_AND_XML)
public Response createEntryWithParam(#FormDataParam('param') String param){
...
}
This second function works te send the parameter in the request. But by adding it, the first stops working.
Sending a request without Content-Type will throw a NullPointerException. Probably because the #Consumes triggers some kind of Content-Type-check, which fails.
Is there a way to have one endpoint accepting POST requests with or without request-body?
edit So, I would like to receive all multipart/form-data requests in the seconds function, and use the first as a kind of catch-all for other POST requests to that endpoint

Currently I have a work-around in place.
If a POST request comes in without MediaType (Content-Type) or request-body, I automatically add an empty JSON object and set the Content-Type accordingly.
#Provider
public class ContentTypeRequestFilter implements ContainerRequestFilter {
#Override
public void filter(ContainerRequestContext crc) throws IOException {
if (crc.getMethod().equals("POST") && crc.getMediaType() == null && crc.getLength() == -1){
crc.getHeaders().add("content-type", MediaType.APPLICATION_JSON);
InputStream in = IOUtils.toInputStream("{}");
crc.setEntityStream(in);
}
}
}
This works, but is kinda hacky in my opinion. I'm interested to know if there are better ways to achieve my desired result.

Jersey - Redirect after POST to outside URL

I'm using Jersey to create REST API. I have one POST method and as a response from that method, the user should be redirected to a custom URL like http://example.com that doesn't have to be related to API.
I was looking at other similar questions on this topic here but didn't find anything that I could use.

I'd suggest altering the signature of the JAX-RS-annotated method to return a javax.ws.rs.core.Response object. Depending on whether you intend the redirection to be permanent or temporary (i.e. whether the client should update its internal references to reflect the new address or not), the method should build and return a Response corresponding to an HTTP-301 (permanent redirect) or HTTP-302 (temporary redirect) status code.
Here's a description in the Jersey documentation regarding how to return custom HTTP responses: https://jersey.java.net/documentation/latest/representations.html#d0e5151. I haven't tested the following snippet, but I'd imagine that the code would look something like this, for HTTP-301:
#POST
public Response yourAPIMethod() {
URI targetURIForRedirection = ...;
return Response.seeOther(targetURIForRedirection).build();
}
...or this, for HTTP-302:
#POST
public Response yourAPIMethod() {
URI targetURIForRedirection = ...;
return Response.temporaryRedirect(targetURIForRedirection).build();
}

This worked for Me
#GET
#Path("/external-redirect2")
#Consumes(MediaType.APPLICATION_JSON)
public Response method2() throws URISyntaxException {
URI externalUri = new URI("https://in.yahoo.com/?p=us");
return Response.seeOther(externalUri).build();
}

HttpServletRequest stored in model gets replaced

I'm working on a legacy code (Spring 2.5.x, Java 1.5), where controller passes Http Servlet Request to view like this:
public ModelAndView handleRequest(HttpServletRequest request, HttpServletResponse response) throws Exception {
Map attributes = new HashMap();
attributes.put("httpRequest", request);
return new ModelAndView("/path/to/page.jsp", attributes);
}
However what happens is that httpRequest attribute does indeed exist in the JSP Page context, but it contains current request (JSP page) and not the original (controller). The passed request is being used to extract some information from the URL. It appears that I can get around that problem by using a bunch of "javax.servlet.forward.*" attributes. This however puzzles me as it is pretty simple thing and I'd be happy to get it to work anyways or at least know exactly why it doesn't work now. Anybody has any ideas?

To begin with, it is a bad idea to store the request as attribute of request. If you need specific data for the current request, you can retrieve it directly using ${requestContext}, if you need to access to the URL, use ${requestContext.requestURL}. If you need to access to parts of this URL to display it in client side, it would be better to parse the url in server side (controller) by first obtaining it using StringBuffer url = request.getRequestURL(); and then setting the required data as attributes.