We have two Microservice Services1 and Service2.
In Service1 we have one PostMapping and return boolean value as below.
#PostMapping
public boolean reset(){
return true
}
When consume from Service2 through restTemplate exchange method it will return in XML format as below.
boolean val = restTemplate.exchange(url, Post method, http entity with header, Boolean.class);
Output
<boolean>true</boolean>
we expecting in JSON format in resttemplate call and if try through postman it will return in JSON.
Related
Right now, I have a class Message representing a JSON object as so
#Value
#Builder
public class Message {
#JsonProperty("#msgType")
String msgType;
#JsonProperty("#type")
String type;
String category;
#Singular("characteristic") List<CharacteristicItem> characteristic;
#Singular("receiver") List<ReceiverItem> receiver;
Sender sender;
}
I would like to send an instance of the class Message as a JSON to remote URL https:example.com/message. How can I create a method that can POST to this URL with the JSON? Note, I am not creating a mapping, I just want to POST to URL and retrieve the HTTP response and convert to string. I'm thinking of using WebClient. Note, I am only interested in seeing if the response is 200, 400, etc., I don't need to handle the response JSON.
If you want to use WebClient you can write below code to post JSON data to URL and retrieve response status code.
WebClient client = WebClient.builder()
.baseUrl("https://example.com")
.build();
Message m = Message.builder().build();
Mono<HttpStatus> httpStatusMono = client.post().uri("/createMessage")
.body(Mono.just(m), Message.class)
.exchange().map(r -> r.statusCode());
// s.value() will give you response status code
httpStatusMono.subscribe(s -> s.value());
If you dont wan't to use WebClient another alternative is RestTemplate
below is the code to achieve the same thing with RestTemplate
RestTemplateBuilder restTemplateBuilder = new RestTemplateBuilder();
ResponseExtractor<Integer> responseExtractor = clientHttpResponse -> {
return Integer.valueOf(clientHttpResponse.getStatusCode().value());
};
Message m = Message.builder().build();
RequestCallback requestCallback = clientHttpRequest -> {
objectMapper.writeValue(clientHttpRequest.getBody(), m);
};
Integer status = restTemplateBuilder.build()
.execute("https://example.com/createMessage",
HttpMethod.POST, requestCallback, responseExtractor);
System.out.println(status);
Am writing a REST endpoint which needs to support both application/x-www-form-urlencoded and application/json as request body simultaneously. I have made below configuration,
#RequestMapping(method = RequestMethod.POST, produces = { MediaType.APPLICATION_JSON_VALUE }, consumes = {
MediaType.APPLICATION_FORM_URLENCODED_VALUE, MediaType.APPLICATION_JSON_VALUE }, path = Constants.ACCESS_TOKEN_V1_ENDPOINT)
public OAuth2Authorization createAccessTokenPost(
#RequestBody(required = false) MultiValueMap<String, String> paramMap) { ..
While it supports application/x-www-form-urlencoded or application/json individually (when I comment out one content type from consumes = {}), but it does not support both simultaneously. Any ideas ?
So RestControllers by default can handle application/json fairly easily and can create a request pojo from a #RequestBody annotated parameter, while application/x-www-form-urlencoded takes a little more work. A solution could be creating an extra RestController method that has the same mapping endpoint to handle the different kinds of requests that come in (application/json, application/x-www-form-urlencoded, etc). This is because application/x-www-form-urlencoded endpoints need to use the #RequestParam instead of the #RequestBody annotation (for application/json).
For instance if I wanted to host a POST endpoint for /emp that takes either application/json or application/x-www-form-urlencoded as Content-Types and uses a service to do something, I could create Overload methods like so
#Autowired
private EmpService empService;
#PostMapping(path = "/emp", consumes = {MediaType.APPLICATION_FORM_URLENCODED_VALUE})
public ResponseEntity createEmp(final #RequestHeader(value = "Authorization", required = false) String authorizationHeader,
final #RequestParam Map<String, String> map) {
//After receiving a FORM URLENCODED request, change it to your desired request pojo with ObjectMapper
final ObjectMapper mapper = new ObjectMapper();
final TokenRequest tokenRequest = mapper.convertValue(map, CreateEmpRequest.class);
return empService.create(authorizationHeader, createEmpRequest);
}
#PostMapping(path = "/emp", consumes = {MediaType.APPLICATION_JSON_VALUE})
public ResponseEntity createEmp(final #RequestHeader(value = "Authorization", required = false) String authorizationHeader,
final #RequestBody CreateEmpRequest createEmpRequest) {
//Receieved a JSON request, the #RequestBody Annotation can handle turning the body of the request into a request pojo without extra lines of code
return empService.create(authorizationHeader, createEmpRequest);
}
As per my findings, spring does not support content types "application/x-www-form-urlencoded", "application/json" and "application/xml" together.
Reason I figured: Spring processes JSON and XML types by parsing and injecting them into the java pojo marked with #RequestBody spring annotation. However, x-www-form-urlencoded must be injected into a MultiValueMap<> object marked with #RequestBody. Two different java types marked with #RequestBody will not be supported simultaneously, as spring may not know where to inject the payload.
A working solution:
"application/x-www-form-urlencoded" can be supported as it is in the API. That is, it can be injected into spring's MultiValueMap<> using an #RequestBody annotation.
To support JSON and XML on the same method, we can leverage servlet specification and spring's class built on top of them to extract the payload as stream.
Sample code:
import org.springframework.http.HttpInputMessage;
import org.springframework.http.HttpStatus;
import org.springframework.http.MediaType;
import org.springframework.http.ResponseEntity;
import org.springframework.http.converter.json.MappingJackson2HttpMessageConverter;
import org.springframework.http.converter.xml.Jaxb2RootElementHttpMessageConverter;
import org.springframework.http.server.ServletServerHttpRequest;
import org.springframework.util.MultiValueMap;
// usual REST service class
#Autowired
private MappingJackson2HttpMessageConverter mappingJackson2HttpMessageConverter;
#Autowired
private Jaxb2RootElementHttpMessageConverter jaxb2RootElementHttpMessageConverter;
public ResponseEntity<Object> authorizationRequestPost(HttpServletResponse response, HttpServletRequest request,#RequestBody(required = false) MultiValueMap<String, String> parameters) {
// this MultiValueMap<String,String> will contain key value pairs of "application/x-www-form-urlencoded" parameters.
// payload object to be populated
Authorization authorization = null;
HttpInputMessage inputMessage = new ServletServerHttpRequest(request) {
#Override
public InputStream getBody() throws IOException {
return request.getInputStream();
}
};
if (request.getContentType().equals(MediaType.APPLICATION_JSON_VALUE)) {
authorization = (Authorization) mappingJackson2HttpMessageConverter.read(Authorization.class, inputMessage);
}
else if (request.getContentType().equals(MediaType.APPLICATION_XML_VALUE)) {
authorization = (Authorization)jaxb2RootElementHttpMessageConverter.read(Authorization.class, inputMessage);
}
else{
// extract values from MultiValueMap<String,String> and populate Authorization
}
// remaining method instructions
}
Point to note that any custom data type/markup/format can be supported using this approach. Spring's org.springframework.http.converter.HttpMessageConverter<> can be extended to write the parsing logic.
Another possible approach could be an AOP style solution which would execute the same logic: parse payload by extracting it from HttpServlet input stream and inject into the payload object.
A third approach will be to write a filter for executing the logic.
It's not possible to handle application/json and application/x-www-form-urlencoded requests simultaneously with a single Spring controller method.
Spring get application/x-www-form-urlencoded data by ServletRequest.getParameter(java.lang.String), the document said:
For HTTP servlets, parameters are contained in the query string or posted form data.
If the parameter data was sent in the request body, such as occurs with an HTTP POST request, then reading the body directly via getInputStream() or getReader() can interfere with the execution of this method.
So, if your method parameter is annotated with #RequestBody, Spring will read request body and parse it to the method parameter object. But application/x-www-form-urlencoded leads Spring to populate the parameter object by invoking ServletRequest.getParameter(java.lang.String).
Just to make it, the above answer doesn't work as even if you do not annotate MultiValueMap with #RequestBody it would always check for contentType==MediaType.APPLICATION_FORM_URLENCODED_VALUE which again in rest of the cases resolves to 415 Unsupported Media Type.
When I use #PostMapping, I will give a CREATED(201) response status together by ResponseStatus annotation. The same as #DeleteMapping, #PutMapping, ect.
So, is there any way to set the default response status at different requestMapping?
You can return ResponseEntity from a method of controller as your mapping response
Example code as follows:
#GetMapping("/get")
public #ResponseBody ResponseEntity<String> get() {
return new ResponseEntity<String>("GET Response", HttpStatus.OK);
}
You can use same mechanism in #DeleteMapping, #PutMapping and others.
You can use ResponseEntity to set the http response on each methods
Example:
ResponseEntity.status(status);
you can give your status for each method with it
Or just add annotation #ResponseStatus:
#ResponseStatus(HttpStatus.OK)
I need a rest end point whose response is HTML. But instead of a view defined in my project, i would like to forward the HTML response from another request made inside that rest end point.
For example, my rest end point makes a http request to an internal service and returns the HTML returned from that service? Is it possible? Any thoughts?
Here is a code example
#RequestMapping("/test")
public String testMe(Model model, #RequestParam("param1") String param1, #RequestParam("param2") String param2)
{
//Make a Http call to an internal service and return the response from that call
return "<RESPONSE_FROM_THAT_CALL>";
}
I would like to return the HTML response from the internal service
You can use a RestTemplate to fetch the result from the other service and just return it as a String:
#Controller
public class MyController {
private RestTemplate restTemplate = new RestTemplate();
#ResponseBody
#RequestMapping("/test")
public String testMe(Model model, #RequestParam("param1") String param1, #RequestParam("param2") String param2) {
URI uri = UriComponentsBuilder.fromHttpUrl("http://www.example.com");
.queryParam("param1", param1)
.queryParam("param2", param2)
.build()
.toUri());
return restTemplate.getForObject(uri, String.class);
}
}
If you'll have more endpoints that you wanna proxy to another service, you should consider using e.g. Zuul as a micro proxy. See e.g. this blog post explaining how you can easily create such a proxy.
I am working with Spring 4.0.7
About Spring MVC, for research purposes, I have the following:
#RequestMapping(value="/getjsonperson",
method=RequestMethod.GET,
produces=MediaType.APPLICATION_JSON_VALUE)
public #ResponseBody Person getJSONPerson(){
logger.info("getJSONPerson - getjsonperson");
return PersonFactory.createPerson();
}
#RequestMapping(value="/getperson.json", method=RequestMethod.GET)
public #ResponseBody Person getPersonJSON(){
logger.info("getPerson - getpersonJSON");
return PersonFactory.createPerson();
}
Each one works fine, observe both for JSON, with and without extension:
/getjsonperson
/getperson.json
Same for XML
#RequestMapping(value="/getxmlperson",
method=RequestMethod.GET,
produces=MediaType.APPLICATION_XML_VALUE
)
public #ResponseBody Person getXMLPerson(){
logger.info("getXMLPerson - getxmlperson");
return PersonFactory.createPerson();
}
#RequestMapping(value="/getperson.xml", method=RequestMethod.GET)
#ResponseBody
public Person getPersonXML(){
logger.info("getPerson - getpersonXML");
return PersonFactory.createPerson();
}
Each one works fine, observe both for XML, with and without extension:
/getxmlperson
/getperson.xml
Now about Restful I have the following:
#RequestMapping(value="/person/{id}/",
method=RequestMethod.GET,
produces={MediaType.APPLICATION_JSON_VALUE,
MediaType.APPLICATION_XML_VALUE})
public ResponseEntity<Person> getPersonCustomizedRestrict(#PathVariable Integer id){
Person person = personMapRepository.findPerson(id);
return new ResponseEntity<>(person, HttpStatus.FOUND);//302
}
Observe the MediaType, it is mixed, for JSON and XML
Through RestTemplate I can indicate the Accept value
if(type.equals("JSON")){
logger.info("JSON");
headers.setAccept(Arrays.asList(MediaType.APPLICATION_JSON));
}
else if(type.equals("XML")){
logger.info("XML");
headers.setAccept(Arrays.asList(MediaType.APPLICATION_XML));
}
….
ResponseEntity<Person> response =
restTemplate.exchange("http://localhost:8080/spring-utility/person/{id}/customizedrestrict",
HttpMethod.GET,
new HttpEntity<Person>(headers),
Person.class,
id
);
Until here, therefore I am able to use one URL/URI to get some data in either XML or JSON formats. It works fine
My problem is with Spring MVC … just consider
#RequestMapping(value="/{id}/person",
method=RequestMethod.GET,
produces={MediaType.APPLICATION_JSON_VALUE,
MediaType.APPLICATION_XML_VALUE})
public #ResponseBody Person getPerson(#PathVariable Integer id){
return personMapRepository.findPerson(id);
}
I can call or activate that handler method (#RequestMapping) through:
jQuery working with Ajax, I am able to indicate the Accept value (JSON for example)
Poster, through the Headers button, I can set the Accept
Question One:
But for a common link? how I can set the Accept value? is possible?
I thought in other way to around this problem.
http://localhost:8080/spring-utility/person/getpersonformat?format=json
http://localhost:8080/spring-utility/person/getpersonformat?format=xml
Observe:
?format
Therefore
#RequestMapping(value="/getpersonformat",
method=RequestMethod.GET,
produces={MediaType.APPLICATION_JSON_VALUE,
MediaType.APPLICATION_XML_VALUE})
public #ResponseBody Person getPerson(#RequestParam String format){
return personMapRepository.findPerson(id);
}
Question Two:
What code for the method shown above must be added to customize the return type format?
I mean, JSON or XML, Is possible?
I thought in the following:
#RequestMapping(value="/getpersonformataltern",
method=RequestMethod.GET
produces={MediaType.APPLICATION_JSON_VALUE,
MediaType.APPLICATION_XML_VALUE}
)
public ResponseEntity<Person> getPersonFormat(#RequestParam String format){
logger.info("getPersonFormat - format: {}", format);
HttpHeaders httpHeaders = new HttpHeaders();
if(format.equals("json")){
logger.info("Ok JSON");
httpHeaders.setContentType(MediaType.APPLICATION_JSON);
}
else{
logger.info("Ok XML");
httpHeaders.setContentType(MediaType.APPLICATION_XML);
}
return new ResponseEntity<>(PersonFactory.createPerson(), httpHeaders, HttpStatus.OK);
}
But:
If I execute the URL:
http://localhost:8080/spring-utility/person/getpersonformataltern?format=json
I get
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<person>
<id>1</id>
<firstName>Manuel</firstName>
<lastName>Jordan</lastName>
…
</person>
Yes in XML!
Note: I can confirm the Console prints Ok JSON
If I execute the URL:
http://localhost:8080/spring-utility/person/getpersonformataltern?format=xml
I get
This XML file does not appear to have any style information associated with it.
The document tree is shown below.
<person>
<id>1</id>
<firstName>Manuel</firstName>
<lastName>Jordan</lastName>
…
</person>
Question Three
What code for the method shown above must be added to fix the JSON output?
I don't know what is wrong or is missing..
There are three questions.
Thank You
Alpha
#Override
public void configureContentNegotiation(ContentNegotiationConfigurer configurer) {
Map<String,MediaType> mediaTypes = new LinkedHashMap<>();
mediaTypes.put("json", MediaType.APPLICATION_JSON);
mediaTypes.put("xml", MediaType.APPLICATION_XML);
configurer.mediaTypes(mediaTypes);
configurer.defaultContentType(MediaType.TEXT_HTML);
}
Using Accept header is really easy to get the format json or xml from the REST service.
This is my Controller, take a look produces section.
#RequestMapping(value = "properties", produces = {MediaType.APPLICATION_JSON_VALUE, MediaType.APPLICATION_XML_VALUE}, method = RequestMethod.GET)
public UIProperty getProperties() {
return uiProperty;
}
In order to consume the REST service we can use the code below where header can be MediaType.APPLICATION_JSON_VALUE or MediaType.APPLICATION_XML_VALUE
HttpHeaders headers = new HttpHeaders();
headers.add("Accept", header);
HttpEntity entity = new HttpEntity(headers);
RestTemplate restTemplate = new RestTemplate();
ResponseEntity<String> response = restTemplate.exchange("http://localhost:8080/properties", HttpMethod.GET, entity,String.class);
return response.getBody();
Edit 01:
In order to work with application/xml, add this dependency
<dependency>
<groupId>com.fasterxml.jackson.dataformat</groupId>
<artifactId>jackson-dataformat-xml</artifactId>
</dependency>
All your problems are that you are mixing content type negotiation with parameter passing. They are things at different levels. More specific, for your question 2, you constructed the response header with the media type your want to return. The actual content negotiation is based on the accept media type in your request header, not response header. At the point the execution reaches the implementation of the method getPersonFormat, I am not sure whether the content negotiation has been done or not. Depends on the implementation. If not and you want to make the thing work, you can overwrite the request header accept type with what you want to return.
return new ResponseEntity<>(PersonFactory.createPerson(), httpHeaders, HttpStatus.OK);
I've preferred using the params filter for parameter-centric content-type.. I believe that should work in conjunction with the produces attribute.
#GetMapping(value="/person/{id}/",
params="format=json",
produces=MediaType.APPLICATION_JSON_VALUE)
public ResponseEntity<Person> getPerson(#PathVariable Integer id){
Person person = personMapRepository.findPerson(id);
return ResponseEntity.ok(person);
}
#GetMapping(value="/person/{id}/",
params="format=xml",
produces=MediaType.APPLICATION_XML_VALUE)
public ResponseEntity<Person> getPersonXML(#PathVariable Integer id){
return GetPerson(id); // delegate
}