How to create Spring Boot controller - java

I have a spring boot application that needs a controller that can handle the following request:
The request is sent by another service through the Post method..
Headers
accept-encoding: gzip,deflate
user-agent: Apache-HttpClient/4.3.6 (java 1.5)
connection: Keep-Alive
host: webhook.site
content-type: application/x-www-form-urlencoded
content-length: 558
Query strings:(empty)
Form values
BillNumber: 41492032464
BillValue: 600000.0
Description: Description
I have this controller, but my application returns an HTTP Error 406:
#RequestMapping(value = "/bills", method = RequestMethod.POST, headers = "Accept=application/x-www-form-urlencoded")
#ResponseBody
#Transactional
public void createBill(UriComponentsBuilder uriComponentsBuilder, final HttpServletRequest request,
final HttpServletResponse response) throws IOException {
}
How should this controller be implemented in my spring boot app?
Many Thanks!

It's not very clear for me but if you use spring boot you can of course create a controller , service and repository or dao.
Indeed, your controller will call your service witch will call the repository.
Let's suppose that you have a client witch call your api.
So the call will look like :
// Suppose that is a spring boot project
Class A {
#Autowired
RestTemplate restTemplate;
public void create(){
HttpHeaders headers = new HttpHeaders();
headers.setAccept(Arrays.asList(MediaType.APPLICATION_JSON));
headers.setContentType((MediaType.APPLICATION_JSON));
headers.add("X-yourCustom-context", "yourCustom");
UriComponentsBuilder builder = UriComponentsBuilder.fromHttpUrl(your_service_url)
.queryParam("params1", "value".queryParam("params2", value2));
HttpEntity<?> entity = new HttpEntity<>(headers);
restTemplate.exchange(builder.build().encode().toUri(), HttpMethod.POST, entity, null); // if you want to return an objectr you put it rather than the null
}
}
Th service api :
#RestController
public class YourController {
#Autowired
private YourService service;
#Autowired
private ObjectMapper objectMapper;
#PostMapping(value = "/bills")
//#ResponseBody if you do not return any think you can not use it
// #CrossOrigin if you want to call your reste from an external project like javascript or angular
//#Transactional you can put it on the top of your service methode
public void createBill(#RequestParam(value = "params1", required = true) String params1,
#RequestParam(value = "params2", required = true) String params2,
#RequestHeader(value = "X-yourCustom-context", required = true) String yourContxt) throws IOException {
// You can then convert your x-context to an object that you have already by using objectMapper.readValue
// Finaly you call you service to create the bill and you passe as params what you get fron the client
}
}
I hope it meets your needs :)

Related

Using RestTemplate in spring-boot returns with 404

I am trying to send a body in a post request in a springboot application using rest template. Here is the controller:(I removed #RequestBody because I used application/x-www-form-urlencoded header)
#RestController
#CrossOrigin
#RequestMapping("/api")
public class SentimentParserController {
#Autowired
private SentimentParserService sentimentParserService;
#RequestMapping(value = "/something", method = RequestMethod.POST, consumes="application/x-www-form-urlencoded")
public ResponseEntity<mcResponse>getTheSentiments( mcSentimentRequestDTO sentimentRequestDTO){
return sentimentParserService.getSentimentsMc(sentimentRequestDTO);
}
}
I want to send the sentimentRequestDTO object(lang, key, and text) as the body in a post request to get the mcResponse:
public mcResponse parseTheSentiments(String text, Languages lang, String key) throws Exception {
RestTemplate restTemplate = new RestTemplate();
String request = "http://localhost:8080";
mcSentimentRequestDTO mSentiments =new mcSentimentRequestDTO(key,"EN",text);
HttpHeaders headers = new HttpHeaders();
headers.add("content-type", "application/x-www-form-urlencoded");
MultiValueMap<String, String> map= new LinkedMultiValueMap<String, String>();
map.add("key", key);
map.add("txt", text);
map.add("lang", Languages.ENGLISH.toString());
HttpEntity<MultiValueMap<String, String>> request1 = new HttpEntity<MultiValueMap<String, String>>(map, headers);
mcResponse response = restTemplate.postForObject(request, request1 , mcResponse.class );
return response;
}
However, I am getting the following error: 404 null.
Can you please help me? Thanks in advance
and here is the service class:
public ResponseEntity<mcResponse> getSentimentsMc(mcSentimentRequestDTO sentimentRequestDTO){
ResponseEntity<mcResponse> dto = null;
try {
dto = sentimentConverter.getTheSentiments(mcsParser.parseTheSentiments(sentimentRequestDTO.getText(),
Languages.ENGLISH, sentimentRequestDTO.getKey()));
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return dto;
}
Looks like variable request should be
String request = "http://localhost:8080/something";
Also if controller class has prefix, this prefix also should be in request.
I mean if your class looks like this
#RestController
#RequestMapping("/myApi")
public class CertificateController {
....
#RequestMapping(value = "/something", method = RequestMethod.POST)
public ResponseEntity<mcResponse>getTheSentiments( mcSentimentRequestDTO sentimentRequestDTO){
return sentimentParserService.getSentimentsMc(sentimentRequestDTO);
}
Then request should be
String request = "http://localhost:8080/myApi/something";
It sounds like the controller isn't getting included in the spring context. If you just have an app annotated with #SpringBootApplication, then make sure that your controller is in a package that is the same as or lower than your annotated application.
To check the controller is being picked up you can add the following logging options to your application.properties
logging.level.org.springframework.beans=debug
logging.level.org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerMapping=trace
When your server starts up you should see something like the following in the log
1. To show the controller is in the spring-context
DefaultListableBeanFactory : Creating shared instance of singleton bean 'sentimentParserController'
2. To show the mapping for the /api/something url
RequestMappingHandlerMapping : Mapped 1 handler method(s) for class SentimentParserController: {public org.springframework.http.ResponseEntity SentimentParserController.getTheSentiments(mcSentimentRequestDTO)={[/api/something],methods=[POST]}}
If you see both of these, then what you say you're doing should work. Just make sure you are sending the request to /api/something and the server is running on port 8080.

Spring boot consuming rest api in Gradle

I'm completely new to Java and trying to consume a rest API with Spring Boot in Gradle, so far I've managed to make a very basic get request to display a message like below
#RestController
public class HelloController {
#RequestMapping(value = "/hello", method = RequestMethod.GET)
public String printWelcome(ModelMap model) {
model.addAttribute("message", "Hello");
return "hello";
}
}
Now, how to extend this get request to make HTTP requests consume an endpoint based on RestTemplate, assuming this is my endpoint that i want to consume like below:
RestTemplate restTemplate = new RestTemplate(); ResponseEntity response = restTemplate.getForEntity("http://aws.services.domain.com/country/id", String.class);
Finally, I want to achieve authorized HTTP GET requests by adding a token Bearer in the Authorization header.
Thank you for answers and suggestions in advance
If you want to add a header, you have to use exchange or execute method.
So, in your case:
HttpHeaders headers = new HttpHeaders();
headers.set("Authorization", "Your Bearer Token");
HttpEntity entity = new HttpEntity(headers);
ResponseEntity<String> response = restTemplate.exchange(
url, HttpMethod.GET, entity, String.class, param);

JAX-RS #Context HttpHeaders always null

I have a Spring Boot application using jax-rs with resteasy (3.0.24). I'm trying to get the HttpHeaders for a request as such:
#DELETE
#Path("/myendpoint")
public Response myMethod(#Context HttpHeaders headers, #Context HttpServletRequest request) {
// headers is always null
}
The headers param is always null even though I'm making the request with multiple headers. As an alternative, I'm extracting them via the HttpServletRequest.getHeaderNames(), but I'd really like know why headers is not populated.
Found the (embarrassing, although I deflect the blame to the author:)) error. #Context HttpHeaders headers was using Spring's implementation and not that from jax-rs.
You gotta get the headers using the #Context then check if the one one you want is there.
#Path("/users")
public class UserService {
#GET
#Path("/get")
public Response addUser(#Context HttpHeaders headers) {
String userAgent = headers.getRequestHeader("user-agent").get(0);
return Response.status(200)
.entity("addUser is called, userAgent : " + userAgent)
.build();
}
}

How to invoke a Spring Controller from Java Filter

This is my scenario: I have two applications, both use Spring MVC. I have a Filter class in one of them and a Controller class in the other one. The requirement is a little weird, when a request is made to the application that contains the filter, this filter should invoke the controller in the another application to "keep alive" the session so I need invoking from filter class a controller class and pass as parameter the JSESSIONID. Any suggestions?
Thanks!
At the end, I achieve my goal using AsyncRestTemplate, the call to the controller from filter was something like this:
HttpHeaders httpHeaders = new HttpHeaders();
httpHeaders.add("Cookie", "JSESSIONID=" + sessionId);
HttpEntity<String> httpEntity = new HttpEntity<String>(null, httpHeaders);
String controllerUrl = CONTROLLER_URL;
ListenableFuture<ResponseEntity<String>> responseEntityListenableFuture = restTemplate.exchange(controllerUrl, HttpMethod.GET, httpEntity, String.class);
responseEntityListenableFuture.addCallback(new ListenableFutureCallback<ResponseEntity<String>>() {
#Override
public void onSuccess(ResponseEntity<String> stringResponseEntity) {
// Nothing to do
}
#Override
public void onFailure(Throwable throwable) {
// Handle your error
}
});

spring mvc rest service redirect / forward / proxy

I have build a web application using spring mvc framework to publish REST services.
For example:
#Controller
#RequestMapping("/movie")
public class MovieController {
#RequestMapping(value = "/{id}", method = RequestMethod.GET)
public #ResponseBody Movie getMovie(#PathVariable String id, #RequestBody user) {
return dataProvider.getMovieById(user,id);
}
Now I need to deploy my application but I have the following problem:
The clients do not have direct access to the computer on which the application resides (There is a firewall). Therefore I need a redirection layer on a proxy machine (accessible by the clients) which calls the actual rest service.
I tried making a new call using RestTemplate:
For Example:
#Controller
#RequestMapping("/movieProxy")
public class MovieProxyController {
private String address= "http://xxx.xxx.xxx.xxx:xx/MyApp";
#RequestMapping(value = "/{id}", method = RequestMethod.GET)
public #ResponseBody Movie getMovie(#PathVariable String id,#RequestBody user,final HttpServletResponse response,final HttpServletRequest request) {
HttpHeaders headers = new HttpHeaders();
headers.setContentType(MediaType.APPLICATION_JSON);
RestTemplate restTemplate = new RestTemplate();
return restTemplate.exchange( address+ request.getPathInfo(), request.getMethod(), new HttpEntity<T>(user, headers), Movie.class);
}
This is ok but I need to rewrite each method in the controller to use the resttemplate. Also, this causes redundant serialization/deserialization on the proxy machine.
I tried writing a generic function using restemplate, but it did not work out:
#Controller
#RequestMapping("/movieProxy")
public class MovieProxyController {
private String address= "http://xxx.xxx.xxx.xxx:xx/MyApp";
#RequestMapping(value = "/**")
public ? redirect(final HttpServletResponse response,final HttpServletRequest request) {
HttpHeaders headers = new HttpHeaders();
headers.setContentType(MediaType.APPLICATION_JSON);
RestTemplate restTemplate = new RestTemplate();
return restTemplate.exchange( address+ request.getPathInfo(), request.getMethod(), ? , ?);
}
I could not find a method of resttemplate which works with request and response objects.
I also tried spring redirect and forward. But redirect does not change the request's client ip address so i think it is useless in this case. I could not forward to another URL either.
Is there a more appropriate way to achieve this?
You can mirror/proxy all requests with this:
private String server = "localhost";
private int port = 8080;
#RequestMapping("/**")
#ResponseBody
public String mirrorRest(#RequestBody String body, HttpMethod method, HttpServletRequest request) throws URISyntaxException
{
URI uri = new URI("http", null, server, port, request.getRequestURI(), request.getQueryString(), null);
ResponseEntity<String> responseEntity =
restTemplate.exchange(uri, method, new HttpEntity<String>(body), String.class);
return responseEntity.getBody();
}
This will not mirror any headers.
Here's my modified version of the original answer, which differs in four points:
It does not make the request body mandatory, and as such does not let GET requests fail.
It copies all headers present in the original request. If you are using another proxy/web server, this can cause issues due to content length/gzip compression. Limit the headers to the ones you really need.
It does not reencode the query params or the path. We expect them to be encoded anyway. Note that other parts of your URL might also be encoded. If that is the case for you, leverage the full potential of UriComponentsBuilder.
It does return error codes from the server properly.
#RequestMapping("/**")
public ResponseEntity mirrorRest(#RequestBody(required = false) String body,
HttpMethod method, HttpServletRequest request, HttpServletResponse response)
throws URISyntaxException {
String requestUrl = request.getRequestURI();
URI uri = new URI("http", null, server, port, null, null, null);
uri = UriComponentsBuilder.fromUri(uri)
.path(requestUrl)
.query(request.getQueryString())
.build(true).toUri();
HttpHeaders headers = new HttpHeaders();
Enumeration<String> headerNames = request.getHeaderNames();
while (headerNames.hasMoreElements()) {
String headerName = headerNames.nextElement();
headers.set(headerName, request.getHeader(headerName));
}
HttpEntity<String> httpEntity = new HttpEntity<>(body, headers);
RestTemplate restTemplate = new RestTemplate();
try {
return restTemplate.exchange(uri, method, httpEntity, String.class);
} catch(HttpStatusCodeException e) {
return ResponseEntity.status(e.getRawStatusCode())
.headers(e.getResponseHeaders())
.body(e.getResponseBodyAsString());
}
}
You can use Netflix Zuul to route requests coming to a spring application to another spring application.
Let's say you have two application: 1.songs-app, 2.api-gateway
In the api-gateway application, first add the zuul dependecy, then you can simply define your routing rule in application.yml as follows:
pom.xml
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-netflix-zuul</artifactId>
<version>LATEST</version>
</dependency>
application.yml
server:
port: 8080
zuul:
routes:
foos:
path: /api/songs/**
url: http://localhost:8081/songs/
and lastly run the api-gateway application like:
#EnableZuulProxy
#SpringBootApplication
public class Application {
public static void main(String[] args) {
SpringApplication.run(Application.class, args);
}
}
Now, the gateway will route all the /api/songs/ requests to http://localhost:8081/songs/.
A working example is here: https://github.com/muatik/spring-playground/tree/master/spring-api-gateway
Another resource: http://www.baeldung.com/spring-rest-with-zuul-proxy
#derkoe has posted a great answer that helped me a lot!
Trying this in 2021, I was able to improve on it a little:
You don't need #ResponseBody if your class is a #RestController
#RequestBody(required = false) allows for requests without a body (e.g. GET)
https and port 443 for those ssl encrypted endpoints (if your server serves https on port 443)
If you return the entire responseEntity instead of only the body, you also get the headers and response code.
Example of added (optional) headers, e.g. headers.put("Authorization", Arrays.asList(String[] { "Bearer 234asdf234"})
Exception handling (catches and forwards HttpStatuses like 404 instead of throwing a 500 Server Error)
private String server = "localhost";
private int port = 443;
#Autowired
MultiValueMap<String, String> headers;
#Autowired
RestTemplate restTemplate;
#RequestMapping("/**")
public ResponseEntity<String> mirrorRest(#RequestBody(required = false) String body, HttpMethod method, HttpServletRequest request) throws URISyntaxException
{
URI uri = new URI("https", null, server, port, request.getRequestURI(), request.getQueryString(), null);
HttpEntity<String> entity = new HttpEntity<>(body, headers);
try {
ResponseEntity<String> responseEntity =
restTemplate.exchange(uri, method, entity, String.class);
return responseEntity;
} catch (HttpClientErrorException ex) {
return ResponseEntity
.status(ex.getStatusCode())
.headers(ex.getResponseHeaders())
.body(ex.getResponseBodyAsString());
}
return responseEntity;
}
proxy controller with oauth2
#RequestMapping("v9")
#RestController
#EnableConfigurationProperties
public class ProxyRestController {
Logger logger = LoggerFactory.getLogger(this.getClass());
#Autowired
OAuth2ProtectedResourceDetails oAuth2ProtectedResourceDetails;
#Autowired
private ClientCredentialsResourceDetails clientCredentialsResourceDetails;
#Autowired
OAuth2RestTemplate oAuth2RestTemplate;
#Value("${gateway.url:http://gateway/}")
String gatewayUrl;
#RequestMapping(value = "/proxy/**")
public String proxy(#RequestBody(required = false) String body, HttpMethod method, HttpServletRequest request, HttpServletResponse response,
#RequestHeader HttpHeaders headers) throws ServletException, IOException, URISyntaxException {
body = body == null ? "" : body;
String path = request.getRequestURI();
String query = request.getQueryString();
path = path.replaceAll(".*/v9/proxy", "");
StringBuffer urlBuilder = new StringBuffer(gatewayUrl);
if (path != null) {
urlBuilder.append(path);
}
if (query != null) {
urlBuilder.append('?');
urlBuilder.append(query);
}
URI url = new URI(urlBuilder.toString());
if (logger.isInfoEnabled()) {
logger.info("url: {} ", url);
logger.info("method: {} ", method);
logger.info("body: {} ", body);
logger.info("headers: {} ", headers);
}
ResponseEntity<String> responseEntity
= oAuth2RestTemplate.exchange(url, method, new HttpEntity<String>(body, headers), String.class);
return responseEntity.getBody();
}
#Bean
#ConfigurationProperties("security.oauth2.client")
#ConditionalOnMissingBean(ClientCredentialsResourceDetails.class)
public ClientCredentialsResourceDetails clientCredentialsResourceDetails() {
return new ClientCredentialsResourceDetails();
}
#Bean
#ConditionalOnMissingBean
public OAuth2RestTemplate oAuth2RestTemplate() {
return new OAuth2RestTemplate(clientCredentialsResourceDetails);
}
If you can get away with using a lower-level solution like mod_proxy that would be the simpler way to go, but if you need more control (e.g. security, translation, business logic) you may want to take a look at Apache Camel: http://camel.apache.org/how-to-use-camel-as-a-http-proxy-between-a-client-and-server.html
I got inspired by Veluria's solution, but I had issues with gzip compression sent from the target resource.
The goal was to omit Accept-Encoding header:
#RequestMapping("/**")
public ResponseEntity mirrorRest(#RequestBody(required = false) String body,
HttpMethod method, HttpServletRequest request, HttpServletResponse response)
throws URISyntaxException {
String requestUrl = request.getRequestURI();
URI uri = new URI("http", null, server, port, null, null, null);
uri = UriComponentsBuilder.fromUri(uri)
.path(requestUrl)
.query(request.getQueryString())
.build(true).toUri();
HttpHeaders headers = new HttpHeaders();
Enumeration<String> headerNames = request.getHeaderNames();
while (headerNames.hasMoreElements()) {
String headerName = headerNames.nextElement();
if (!headerName.equals("Accept-Encoding")) {
headers.set(headerName, request.getHeader(headerName));
}
}
HttpEntity<String> httpEntity = new HttpEntity<>(body, headers);
RestTemplate restTemplate = new RestTemplate();
try {
return restTemplate.exchange(uri, method, httpEntity, String.class);
} catch(HttpStatusCodeException e) {
return ResponseEntity.status(e.getRawStatusCode())
.headers(e.getResponseHeaders())
.body(e.getResponseBodyAsString());
}
}
You need something like jetty transparent proxy, which actually will redirect your call, and you get a chance to overwrite the request if you needed. You may get its detail at http://reanimatter.com/2016/01/25/embedded-jetty-as-http-proxy/

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