Why JAX-RS POST does not work with multivalued map - java

I have JAX-RS 2.8.9 with Spring 4.3.4 app. I perform a very simple POST request to the following server code
#POST
#Consumes({MediaType.APPLICATION_FORM_URLENCODED})
#Produces({MediaType.APPLICATION_JSON, MediaType.APPLICATION_XML})
public Response test(MultivaluedMap<String, String> work) {
return Response.ok(work.keySet().size()).build();
}
I test with curl:
curl -i -X POST 'http://localhost:XXX/some/test' -d "param=value&param2=value2" -H "Content-Type: application/x-www-form-urlencoded"
I get the following warning
A servlet request to the URI http://localhost:XXX/some/test contains form parameters in the request body but the request body has been consumed by the servlet or a servlet filter accessing the request parameters. Only resource methods using #FormParam will work as expected. Resource methods consuming the request body by other means will not work as expected.
About which I found only cause that involve connection issues, apparently I don't have.
According to documentation this is the way to handle a case when we have a variable number of FormParams passed.
This works, though.
#POST
#Consumes({MediaType.APPLICATION_FORM_URLENCODED})
#Produces({MediaType.APPLICATION_JSON, MediaType.APPLICATION_XML})
public Response test(#FormParam("param") String param) {
return Response.ok(param).build();
}
What can be the reason the multivalued map doesn't? Could it be some filtering? What is an alternative for unknown number of parameters?
UPDATE
Is is due to a particularity of Jersey + Spring.
A solution can be found in this answer.

What can be the reason the multivalued map doesn't? Could it be some filtering? What is an alternative for unknown number of parameters?
By default, it seems your JAX-RS implementation is detecting the form-input and reading/processing the body before it gets to your method. Have you tried:
#POST
#Consumes({MediaType.APPLICATION_FORM_URLENCODED})
#Produces({MediaType.APPLICATION_JSON, MediaType.APPLICATION_XML})
public Response test(Form workForm) {
MultivaluedMap<String,String> work = workForm.asMap();
return Response.ok(work.keySet().size()).build();
}
?
Form is a special JAX-RS class that encapsulates all the form parameters and should be usable as an input parameter to your method.

Related

Java Spring - GET Request with two parameters

I want to make a GET request to my server that receives two parameters, uniqueConfig and commitHash. The code for this operation in my Controller class is as follows:
#GetMapping("/statsUnique")
public ResponseEntity<Object> hasEntry(#RequestParam("uniqueConfig") String uniqueConfig,
#RequestParam("commitHash") String commitHash) {
Optional<Stats> statsOptional =
codecService.findByUniqueConfigAndCommitHash(uniqueConfig, commitHash);
if (statsOptional.isPresent()) {
return ResponseEntity.status(HttpStatus.OK).body(true);
}
return ResponseEntity.status(HttpStatus.OK).body(false);
}
The issue is, when I try to make the GET request using Postman, the server returns a 400 - Bad Request with the following error message:
MissingServletRequestParameterException: Required request parameter 'uniqueConfig' for method parameter type String is not present]
my JSON on Postman looks like this:
{
"commitHash": "ec44ee022959410f9596175b9424d9fe1ece9bc8",
"uniqueConfig": "bowing_22qp_30fr_29.97fps_fast-preset"
}
Please note that those aren't the only attributes and I've tried making the same request with all of them on the JSON. Nonetheless, I receive the same error.
What am I doing wrong here?
A GET request doesn't (or at least shouldn't) have a body. Parameters defined by the #RequestParam annotations should be sent in the query string, not a JSON body, i.e., the request should be something like
http://myhost/statsUnique?commitHash=commitHash&uniqueConfig=bowing_22qp_30fr_29.97fps_fast-preset

POST doesn't work Spring java

I have an web application and I'm trying to creat a simple POSt method that will have a value inside the body request:
#RequestMapping(value = "/cachettl", method = RequestMethod.POST)
#CrossOrigin(origins = "http://localhost:3000")
public #ResponseBody String updateTtl(#RequestBody long ttl) {
/////Code
}
My request which I call from some rest client is:
POST
http://localhost:8080/cachettl
Body:
{
"ttl": 5
}
In the response I get 403 error "THE TYPE OF THE RESPONSE BODY IS UNKNOWN
The server did not provide the mandatory "Content-type" header."
Why is that happening? I mention that other GET requests are working perfectly.
Thanks!
Edit:
When I tried it with postman the error message I got is "Invalid CORS request".
Spring application just doesn't know how to parse your message's body.
You should provide "header" for your POST request to tell Spring how to parse it.
"Content-type: application/json" in your case.
You can read more about http methods here: https://developer.mozilla.org/en-US/docs/Learn/HTML/Forms/Sending_and_retrieving_form_data
Updated:
Just in case of debug, remove useless annotations to test only POST mechanism. Also, change types of arg and return type. And try to use case-sensitive header.
#RequestMapping(value = "/cachettl", method = RequestMethod.POST)
public void updateTtl(#RequestBody String ttl) {
System.out.println("i'm working");
}
Since the error is about the response type, you should consider adding a produces attribute, i.e :
#RequestMapping(value = "/cachettl", method = RequestMethod.POST, produces=MediaType.APPLICATION_JSON_VALUE)
Since you are also consuming JSON, adding a consumes attribute won't hurt either :
#RequestMapping(value = "/cachettl", method = RequestMethod.POST, consumes=MediaType.APPLICATION_JSON_VALUE, produces=MediaType.APPLICATION_JSON_VALUE)
The error message is slightly misleading. Your server code is not being hit due an authentication error.
Since you say spring-security is not in play then I suspect you're being bounced by a CORS violation maybe due to a request method restriction. The response body generated by this failure (if any at all) is automatic and will not be of the application/json type hence the client failure. I suspect if you hit the endpoint with something that doesn't care for CORS such as curl then it will work.
Does your browser REST client allow you to introspect the CORS preflight requests to see what it's asking for?

Content-type and #ResponseBody in spring

It could be very simple but it will be very helpful for me to understand...
I used #ResponseBody in my restcontroller to return String value to browser. The response string is successfully received in browser.
ie:
#RequestMapping(value="/foo", method=RequestMethod.GET)
#ResponseBody
public String foo() {
return "bar";
}
What is the content-type of above response? If this is going to be like writing setAttribute in servlet response what could the attribute name?
If the browser accept only "application/json" how spring will treat the response?
Submitted code produces text/html, as do all mapped Controller methods by default. If you want to produce application/json, you have to change your RequestMapping to
#RequestMapping(value="/foo", method=RequestMethod.GET, produces = "application/json")
However this is not a valid Json String, you would have to change it because the method you submitted would return empty body. The submitted example would be valid text/plain.
When the request contains header "Accept: application/json" and other content type is returned, Spring returns Json-type response explaining that HttpMediaTypeNotAcceptableException was thrown.
Regarding the servlet analogy - please explain, I don't fully understand what you mean. The String is returned as response body, it's very different from request attributes. What would you like to achieve?
I assume the content type will be plain/text. If the request sets accept to "application/json" it depends on your browser/tool. Most rest clients won't display it as it is not application/json. If you invoke the API directly I would assume it is displayed due to browser content sniffing (can be disabled via a header).

How to access parameters in a RESTful POST method

My POST method looks like this:
#POST
#Consumes({"application/json"})
#Path("create/")
public void create(String param1, String param2){
System.out.println("param1 = " + param1);
System.out.println("param2 = " + param2);
}
When I create a Jersey Client in Netbeans the method who calls the post method looks like this:
public void create(Object requestEntity){
webResource.path("create").type(MediaType.APPLICATION_JSON).post(requestEntity);
}
When running this test:
#Test
public void hello(){
String json = "{param1=\"hello\",param2=\"hello2\"}";
this.client.create(json);
}
It gives the following output in the server:
INFO: param1 = {param1="hello",param2="hello2"}
INFO: param2 =
What do I need to change so that the parameters are giving the correct value?
Your #POST method should be accepting a JSON object instead of a string. Jersey uses JAXB to support marshaling and unmarshaling JSON objects (see the jersey docs for details). Create a class like:
#XmlRootElement
public class MyJaxBean {
#XmlElement public String param1;
#XmlElement public String param2;
}
Then your #POST method would look like the following:
#POST #Consumes("application/json")
#Path("/create")
public void create(final MyJaxBean input) {
System.out.println("param1 = " + input.param1);
System.out.println("param2 = " + input.param2);
}
This method expects to receive JSON object as the body of the HTTP POST. JAX-RS passes the content body of the HTTP message as an unannotated parameter -- input in this case. The actual message would look something like:
POST /create HTTP/1.1
Content-Type: application/json
Content-Length: 35
Host: www.example.com
{"param1":"hello","param2":"world"}
Using JSON in this way is quite common for obvious reasons. However, if you are generating or consuming it in something other than JavaScript, then you do have to be careful to properly escape the data. In JAX-RS, you would use a MessageBodyReader and MessageBodyWriter to implement this. I believe that Jersey already has implementations for the required types (e.g., Java primitives and JAXB wrapped classes) as well as for JSON. JAX-RS supports a number of other methods for passing data. These don't require the creation of a new class since the data is passed using simple argument passing.
HTML <FORM>
The parameters would be annotated using #FormParam:
#POST
#Path("/create")
public void create(#FormParam("param1") String param1,
#FormParam("param2") String param2) {
...
}
The browser will encode the form using "application/x-www-form-urlencoded". The JAX-RS runtime will take care of decoding the body and passing it to the method. Here's what you should see on the wire:
POST /create HTTP/1.1
Host: www.example.com
Content-Type: application/x-www-form-urlencoded;charset=UTF-8
Content-Length: 25
param1=hello&param2=world
The content is URL encoded in this case.
If you do not know the names of the FormParam's you can do the following:
#POST #Consumes("application/x-www-form-urlencoded")
#Path("/create")
public void create(final MultivaluedMap<String, String> formParams) {
...
}
HTTP Headers
You can using the #HeaderParam annotation if you want to pass parameters via HTTP headers:
#POST
#Path("/create")
public void create(#HeaderParam("param1") String param1,
#HeaderParam("param2") String param2) {
...
}
Here's what the HTTP message would look like. Note that this POST does not have a body.
POST /create HTTP/1.1
Content-Length: 0
Host: www.example.com
param1: hello
param2: world
I wouldn't use this method for generalized parameter passing. It is really handy if you need to access the value of a particular HTTP header though.
HTTP Query Parameters
This method is primarily used with HTTP GETs but it is equally applicable to POSTs. It uses the #QueryParam annotation.
#POST
#Path("/create")
public void create(#QueryParam("param1") String param1,
#QueryParam("param2") String param2) {
...
}
Like the previous technique, passing parameters via the query string does not require a message body. Here's the HTTP message:
POST /create?param1=hello&param2=world HTTP/1.1
Content-Length: 0
Host: www.example.com
You do have to be particularly careful to properly encode query parameters on the client side. Using query parameters can be problematic due to URL length restrictions enforced by some proxies as well as problems associated with encoding them.
HTTP Path Parameters
Path parameters are similar to query parameters except that they are embedded in the HTTP resource path. This method seems to be in favor today. There are impacts with respect to HTTP caching since the path is what really defines the HTTP resource. The code looks a little different than the others since the #Path annotation is modified and it uses #PathParam:
#POST
#Path("/create/{param1}/{param2}")
public void create(#PathParam("param1") String param1,
#PathParam("param2") String param2) {
...
}
The message is similar to the query parameter version except that the names of the parameters are not included anywhere in the message.
POST /create/hello/world HTTP/1.1
Content-Length: 0
Host: www.example.com
This method shares the same encoding woes that the query parameter version. Path segments are encoded differently so you do have to be careful there as well.
As you can see, there are pros and cons to each method. The choice is usually decided by your clients. If you are serving FORM-based HTML pages, then use #FormParam. If your clients are JavaScript+HTML5-based, then you will probably want to use JAXB-based serialization and JSON objects. The MessageBodyReader/Writer implementations should take care of the necessary escaping for you so that is one fewer thing that can go wrong. If your client is Java based but does not have a good XML processor (e.g., Android), then I would probably use FORM encoding since a content body is easier to generate and encode properly than URLs are. Hopefully this mini-wiki entry sheds some light on the various methods that JAX-RS supports.
Note: in the interest of full disclosure, I haven't actually used this feature of Jersey yet. We were tinkering with it since we have a number of JAXB+JAX-RS applications deployed and are moving into the mobile client space. JSON is a much better fit that XML on HTML5 or jQuery-based solutions.

Null content-type when migrating from Jersey to RESTEasy.

So I wrote a sample REST resource that works like a charm in Jersey/Tomcat, but when I take it to RestEASY/Tomcat it blows. I mean really? what happened to working out of the box. Anyway a little frustrated. I get this error when trying to access the resource(http://localhost:7070/mg/mytest)
"content-type was null and expecting to extract a body"
7842 [http-7070-2] ERROR com.loyalty.mg.rest.exception.MGExceptionMapper - Error caught in the exception mapper -
org.jboss.resteasy.spi.BadRequestException: content-type was null and expecting to extract a body
at org.jboss.resteasy.core.MessageBodyParameterInjector.inject(MessageBodyParameterInjector.java:131)
at org.jboss.resteasy.core.MethodInjectorImpl.injectArguments(MethodInjectorImpl.java:98)
at org.jboss.resteasy.core.MethodInjectorImpl.invoke(MethodInjectorImpl.java:121)
at org.jboss.resteasy.core.ResourceMethod.invokeOnTarget(ResourceMethod.java:247)
at org.jboss.resteasy.core.ResourceMethod.invoke(ResourceMethod.java:212)
at org.jboss.resteasy.core.ResourceMethod.invoke(ResourceMethod.java:202)
#Path("/mytest")
public class TestResource {
#GET
public Response getData()
I guess the question also is - is RestEASY any better than Jersey, this is just the start and I am getting errors. Should I just stick to Jersey?
Also already tried this as well :)
<context-param>
<param-name>resteasy.media.type.mappings</param-name>
<param-value>json : application/json, xml : application/xml</param-value>
</context-param>
The code that throws that exception looks like this:
final MediaType mediaType = request.getHttpHeaders().getMediaType();
if (mediaType == null) {
throw new BadRequestException(
"content-type was null and expecting to extract a body");
}
The problem seems to be that RestEASY cannot figure out a content type from the headers of the request that it received. This suggests that either that the content type in the request is bogus, or that there is a problem with the way that you have configured RestEASY.
I guess the question also is - is RestEASY any better than Jersey, this is just the start and I am getting errors. Should I just stick to Jersey?
I cannot answer that. However, I think you are being too quick to blame RestEASY for something that could be your code's fault.
A classic cause of this, is if you have code like this:
#GET
#Path("/foo/{bar}")
#Produces(MediaType.TEXT_HTML)
public Response foo(#PathParam("bar") String bar) {
...and you forget to annotate the bar argument with #PathParam. Then RestEasy thinks it should be reading bar from the body of the request, instead of from the URL path, and will chuck this exception.
That doesn't seem to be what's happening in your case, but I got the same exception, and this was the cause.
RestEASY vs Jersey is hard to say:
http://www.infoq.com/news/2008/10/jaxrs-comparison
Regarding your error, you can control the content type via annotations, what happens if you place #Produces annotation, for example:
#Produces("application/json")
#GET
public Response getData() {
...
}
Well I know this requested is dated, and so much on the internet old..in a year of two everything usually changes and works better. So RestEasy should not get a bad rap in comparison to other non-propertary RESTLET frameworks.
Actually I think JBoss RestEasy has the lightest footprint, it's not bloated with unnecessary *.jars, flexible, fully certified JAX-RS implementation, complete and its ease of use is beyond comparison.
Some eluded, that a GET request should not expect a Content_Type on the request, (And I agree), but with a every GET request one must indicate what you intend on sending back to the requestor? Right! (will it be JSON, XML, plain text, XML and a sheetsheet, multi-part, etc). Well RestEasy, JBoss's framework addresses this with annotation as shown below, and configurable per URL REST request. Therefore, therein is your answer
#GET
#Path("/echo/{message}")
#Produces("text/plain")
public String echo(#PathParam("message")String message){
return message;
}
#GET
#Path("/employees")
#Produces("application/xml")
#Stylesheet(type="text/css", href="${basepath}foo.xsl")
public List<Employee> listEmployees(){
return new ArrayList<Employee>(employees.values());
}
#GET
#Path("/employee/{employeeid}")
#Produces("application/xml")
public Employee getEmployee(#PathParam("employeeid")String employeeId){
return employees.get(employeeId);
}
#GET
#Path("/json/employees/")
**#Produces("application/json")**
public List<Employee> listEmployeesJSON(){
return new ArrayList<Employee>(employees.values());
}
a GET request must not have a body, and an application must not expet a Content-Type header.
If this is a bug of RestEASY, it makes one wonder how many people really are using the software.
EDIT
RFC2616 $4.3
A message-body MUST NOT be included in
a request if the specification of the
request method (section 5.1.1) does
not allow sending an entity-body in
requests.
A server SHOULD read and forward a
message-body on any request; if the
request method does not include
defined semantics for an entity-body,
then the message-body SHOULD be
ignored when handling the request.
The GET method does not "does not allow sending an entity-body in request" therefore a GET request COULD have a body. But GET "does not include defined semantics for an entity-body" therefore the body should be ignored anyway.
In any case, RestEASY should not have required the presence of Content-Type in a GET request.

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