How can I get failed HTTP request body in java? - java

I want to log all HTTP requests.
Normally, I can get a request body for a successful request with the code below.
But I don't get the request body if a request fails.
When I try to get the body of the failed request I only get an empty string.
How can I get failed HTTP request body in java?
-Filter class-
#Component
#Slf4j
public class HttpLogFilter extends OncePerRequestFilter {
#Override
protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response, FilterChain filterChain) throws IOException, ServletException {
long startTime = System.currentTimeMillis();
String requestId = UUID.randomUUID().toString();
response.addHeader(REQUEST_ID_PROPERTY_NAME, requestId);
ThreadContext.put(REQUEST_ID_PROPERTY_NAME, requestId);
ContentCachingRequestWrapper requestWrapper = new ContentCachingRequestWrapper(request);
ContentCachingResponseWrapper responseWrapper = new ContentCachingResponseWrapper(response);
filterChain.doFilter(requestWrapper, responseWrapper);
HttpLogDTO httpLog = collectHttpInfo(requestWrapper, responseWrapper);
responseWrapper.copyBodyToResponse();
long endTime = System.currentTimeMillis();
httpLog.setDuration(endTime - startTime);
log.info(httpLog.toString());
}
private HttpLogDTO collectHttpInfo(HttpServletRequest request, HttpServletResponse response) {
String scheme = request.getScheme();
String host = request.getServerName();
String port = String.valueOf(request.getLocalPort());
String path = request.getServletPath();
String parameters = request.getParameterMap().keySet().stream()
.map(key -> key + "=" + request.getParameterMap().get(key)[0]).collect(Collectors.joining("&"));
Map<String, List<String>> requestHeaders = Collections.list(request.getHeaderNames())
.stream()
.collect(Collectors.toMap(
Function.identity(),
h -> Collections.list(request.getHeaders(h))
));
Map<String, String> responseHeaders = response.getHeaderNames()
.stream()
.collect(Collectors.toMap(h -> h, response::getHeader));
return HttpLogDTO.builder()
.protocol(request.getProtocol())
.remote(request.getRemoteAddr())
.method(request.getMethod())
.uri(scheme + "://" + host + ":" + port + path + (StringUtils.isNotBlank(parameters) ? "?" + parameters : ""))
.host(host)
.path(path)
.scheme(scheme)
.port(port)
.requestHeaders(requestHeaders.toString())
.requestBody(new String(((ContentCachingRequestWrapper) request).getContentAsByteArray()))
.statusCode(String.valueOf(response.getStatus()))
.statusValue(Objects.requireNonNull(HttpStatus.resolve(response.getStatus())).getReasonPhrase())
.responseHeaders(responseHeaders.toString())
.responseBody(new String(((ContentCachingResponseWrapper) response).getContentAsByteArray()))
.build();
}
}

[SOLVED]
The problem is not in the above Filter class.
The problem is that I did write the code like I don't expect body in the controller class.
Problem solved after adding my POJO class with #RequestBody annotation in the method.
Old Code
#PostMapping("/post")
public ResponseEntity post() {
throw new BusinessValidationException(BusinessValidationRule.CITY_NOT_FOUND);
}
New Code
#PostMapping("/post")
public ResponseEntity post(#RequestBody Object body) {
throw new BusinessValidationException(BusinessValidationRule.CITY_NOT_FOUND);
}

Related

Cannot redirect after facebook login using response entity in spring boot

Ok, so I am trying to achieve facebook authentication in my application but after success user is not redirected to homepage even though location header is set.
This is my current scenario.
Front-End call:
#GetMapping(value = "/login/facebook")
public String loginFacebook() {
String facebookLoginUrl = String.valueOf(this.restTemplate.getForEntity(this.serverApi + "/login/facebook",String.class).getHeaders().get("Location"));
facebookLoginUrl = facebookLoginUrl.substring(1,facebookLoginUrl.length()-1);
System.out.println(facebookLoginUrl);
return "redirect:" + facebookLoginUrl;
}
Back-End:
#RequestMapping(value = "/login/facebook", method = RequestMethod.GET)
public String startFacebookProcess() {
this.facebookConnectionFactory = new FacebookConnectionFactory(appId,appSecret);
OAuth2Operations operations = this.facebookConnectionFactory.getOAuthOperations();
OAuth2Parameters parameters = new OAuth2Parameters();
// promeni url-a za front-enda
parameters.setRedirectUri("http://localhost:8080/login/returnFromFacebook");
parameters.setScope(this.scope);
System.out.println("In startFacebookProcess");
String url = operations.buildAuthorizeUrl(parameters);
System.out.println(url);
return "redirect:" + url;
}
After that, the user is being redirected to the official facebook login page where he allows his details to be used.
Then he performs a GET request to my Front-End with his authorization code:
#GetMapping(value = "/login/returnFromFacebook")
public ResponseEntity getFacebookData(#RequestParam("code") String authorizationCode){
System.out.println(authorizationCode);
ResponseEntity response = this.restTemplate.getForEntity(this.serverApi +
"/login/returnFromFacebook?code=" + authorizationCode, ResponseEntity.class);
if(response.getStatusCode().is2xxSuccessful()){
return response;
}
return new ResponseEntity(HttpStatus.CONFLICT);
}
My Back-End is being called and I contact facebook to fetch the user data using his authorization code. Then I return a ResponseEntity which inherited all the HttpServletResponse headers and cookies.
#RequestMapping(value = "/login/returnFromFacebook", method = RequestMethod.GET)
public ResponseEntity getDataFromFacebook(#RequestParam("code") String authorizationCode,
HttpServletResponse response) throws IOException {
// leg 2
OAuth2Operations operations = this.facebookConnectionFactory.getOAuthOperations();
AccessGrant accessGrant = operations.exchangeForAccess(authorizationCode,
"http://localhost:8080/login/returnFromFacebook",null);
// leg 3
System.out.println("code: " + authorizationCode);
Connection<Facebook> connection = this.facebookConnectionFactory.createConnection(accessGrant);
User currentUser = connection.getApi().fetchObject("me", User.class,"email,first_name,last_name");
System.out.println("Email: " + currentUser.getEmail());
if(this.appUserDAO.findUserAccountByEmail(currentUser.getEmail()) == null){
Map<String, String> facebookDetailsMap = new LinkedHashMap<>();
facebookDetailsMap.put("email",currentUser.getEmail());
facebookDetailsMap.put("name",currentUser.getFirstName() + " " + currentUser.getLastName());
this.appUserDAO.saveFacebookAccount(facebookDetailsMap);
}
// Create JWT Token
String token = JWT.create()
.withSubject(currentUser.getEmail())
.withExpiresAt(new Date(System.currentTimeMillis() + JwtProperties.EXPIRATION_TIME))
.sign(HMAC512(JwtProperties.SECRET.getBytes()));
JwtAuthenticationFilter.setJwtCookie(response,token);
System.out.println(response.getStatus() + " " + response.getHeader("set-cookie"));
response.setHeader("Location", "http://localhost:8080/");
// HttpHeaders headers = new HttpHeaders();
// headers.add(index");
return new ResponseEntity<>(HttpStatus.CREATED);
}
This is the received response header in the browser. The cookies are set and everything but user is not being redirected to Location header. :
I tried to return a String "redirect:/" from GetFacebookData(Front-End) but the response cookies and headers are not being applied. I don't know why the Location header is not working.
I fixed it by returning the 'index' template if the back-end call was sucessful but also apply the cookie header into the original response (which was to the front-end) using HttpServletResponse (this is not possible with ResponseEntity btw). With HttpServletResponse you dont have to return it to the browser, it applies everything by default. With ResponseEntity you have to return ResponseEntity Object in order to apply headers. This is how the function looks like now:
#GetMapping(value = "/login/returnFromFacebook")
public String getFacebookData(#RequestParam("code") String authorizationCode, HttpServletResponse httpServletResponse) throws IOException {
System.out.println(authorizationCode);
ResponseEntity response = this.restTemplate.getForEntity(this.serverApi +
"/login/returnFromFacebook?code=" + authorizationCode, ResponseEntity.class);
System.out.println(response.getStatusCodeValue() + " " + response.getHeaders().get("Location"));
//set cookie for original request
String jwtCookieHeader = String.valueOf(response.getHeaders().get("set-cookie"));
jwtCookieHeader = jwtCookieHeader.substring(1,jwtCookieHeader.length()-1);
httpServletResponse.setHeader("set-cookie", jwtCookieHeader);
if(response.getStatusCode().is2xxSuccessful()){
return "redirect:/";
}
return String.valueOf(new ResponseEntity(HttpStatus.CONFLICT));
}

How to resolve URI encoding problem in spring-boot?

I am using spring-boot to host a http request service.
#RequestMapping("/extract")
#SuppressWarnings("unchecked")
#ResponseBody
public ExtractionResponse extract(#RequestParam(value = "extractionInput") String input) {
// LOGGER.info("input: " + input);
JSONObject inputObject = JSON.parseObject(input);
InputInfo inputInfo = new InputInfo();
//Object object = inputObject.get(InputInfo.INPUT_INFO);
JSONObject object = (JSONObject) inputObject.get(InputInfo.INPUT_INFO);
String inputText = object.getString(InputInfo.INPUT_TEXT);
inputInfo.setInputText(inputText);
return jnService.getExtraction(inputInfo);
}
When there is a % sign, as follows, it got an errror:
http://localhost:8090/extract?extractionInput={"inputInfo":{"inputText":"5.00%"}}
The error message is below:
2018-10-09 at 19:12:53.340 [http-nio-8090-exec-1] INFO org.apache.juli.logging.DirectJDKLog [180] [log] - Character decoding failed. Parameter [extractionInput] with value [{"inputInfo":{"inputText":"5.0022:%225.00%%22}}] has been ignored. Note that the name and value quoted here may be corrupted due to the failed decoding. Use debug level logging to see the original, non-corrupted values.
Note: further occurrences of Parameter errors will be logged at DEBUG level.
2018-10-09 at 19:12:53.343 [http-nio-8090-exec-1] WARN org.springframework.web.servlet.handler.AbstractHandlerExceptionResolver [140] [resolveException] - Resolved [org.springframework.web.bind.MissingServletRequestParameterException: Required String parameter 'extractionInput' is not present]
How to configure the URI encoding to fix this issue in my spring-boot configurations?
EDIT: Possible Java client code to make the request:
public String process(String question) {
QueryInfo queryInfo = getQueryInfo(question);
ObjectMapper mapper = new ObjectMapper();
mapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
String jsonResult = null;
try {
String jsonStr = mapper.writeValueAsString(queryInfo);
String urlStr = Parameters.getQeWebserviceUrl() + URLEncoder.encode(jsonStr, "UTF-8");
URL url = new URL(urlStr);
BufferedReader in = new BufferedReader(new InputStreamReader(url.openStream()));
jsonResult = in.readLine();
in.close();
} catch (Exception jpe) {
jpe.printStackTrace();
}
return jsonResult
}
Without encoding from your client side - you could still achieve this if you follow any of the following strategies by encoding before the request is processed in the servlet:
use Spring preprocessor bean to preprocess the controller endpoint request
use Spring AspectJ to preprocess the controller endpoint request
use Spring servlet filter to preprocess the controller endpoint request
With any of the above cross-cutting strategies, you could encode the request URL and pass back to the endpoint.
For example below is one implmentation using Filter. You could possibly do some caching there if you need better performance.
#Component
public class SomeFilter implements Filter {
private static final Logger LOGGER = LoggerFactory.getLogger(SomeFilter.class);
#Override
public void init(final FilterConfig filterConfig) throws ServletException {
}
#Override
public void doFilter(final ServletRequest servletRequest, final ServletResponse servletResponse, final FilterChain filterChain) throws IOException, ServletException {
HttpServletRequest request = (HttpServletRequest) servletRequest;
HttpServletRequest modifiedRequest = new SomeHttpServletRequest(request);
filterChain.doFilter(modifiedRequest, servletResponse);
}
#Override
public void destroy() {
}
class SomeHttpServletRequest extends HttpServletRequestWrapper {
HttpServletRequest request;
SomeHttpServletRequest(final HttpServletRequest request) {
super(request);
this.request = request;
}
#Override
public String getQueryString() {
String queryString = request.getQueryString();
LOGGER.info("Original query string: " + queryString);
try {
// You need to escape all your non encoded special characters here
String specialChar = URLEncoder.encode("%", "UTF-8");
queryString = queryString.replaceAll("\\%\\%", specialChar + "%");
String decoded = URLDecoder.decode(queryString, "UTF-8");
LOGGER.info("Modified query string: " + decoded);
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
return queryString;
}
#Override
public String getParameter(final String name) {
String[] params = getParameterMap().get(name);
return params.length > 0 ? params[0] : null;
}
#Override
public Map<String, String[]> getParameterMap() {
String queryString = getQueryString();
return getParamsFromQueryString(queryString);
}
#Override
public Enumeration<String> getParameterNames() {
return Collections.enumeration(getParameterMap().keySet());
}
#Override
public String[] getParameterValues(final String name) {
return getParameterMap().get(name);
}
private Map<String, String[]> getParamsFromQueryString(final String queryString) {
String decoded = "";
try {
decoded = URLDecoder.decode(queryString, "UTF-8");
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
String[] params = decoded.split("&");
Map<String, List<String>> collect = Stream.of(params)
.map(x -> x.split("="))
.collect(Collectors.groupingBy(
x -> x[0],
Collectors.mapping(
x -> x.length > 1 ? x[1] : null,
Collectors.toList())));
Map<String, String[]> result = collect.entrySet().stream()
.collect(Collectors.toMap(
x -> x.getKey(),
x -> x.getValue()
.stream()
.toArray(String[]::new)));
return result;
}
}
}
You probably need to URLEncode the query parameter, e.g.
http://localhost:8090/extract?extractionInput=%7B%22inputInfo%22%3A%7B%22inputText%22%3A%225.00%25%22%7D%7D
The generally easier way to pass a parameter like this is to use an HTTP POST instead of a GET, and pass your JSON object in the body.
This is not a best practice for a REST API.
Try to normalize your URLs in object oriented way to capture path variables.
if your object likes:
param1:{
param2:{
param3: ""
}
}
use url pattern to capture attribute as:
class/param1/param2/{param3}
otherwise you will get more problems when altering front-end technologies while keeping back-end REST API same.

How to do GET API Request with URL params?

Client client = ClientBuilder.newClient();
urlApi="https://localhost:123/demo/api/v1/rows/search?";
WebTarget webTarget = client.target(urlApi);
for (Map.Entry<String, String> entry : queryParams.entrySet()) {
webTarget.queryParam(entry.getKey(), entry.getValue());
}
webTarget.queryParam("searchConditions",webTarget.queryParam("mobileNo","+9999999999"));
Invocation.Builder builder = webTarget.request();
builder.header("id", "ABC");
String asB64 = Base64.getEncoder().encodeToString("ABC:PWD".getBytes("utf-8"));
logger.debug("Calling API "+urlApi);
builder.header("Authorization", "Basic "+asB64);
builder.header("Content-type", MediaType.APPLICATION_JSON);
response = builder.get();
responseData = response.readEntity(String.class);
System.out.println(responseData);
I am trying to do GET request with searchCondition as Key and value as {mobileNo="+919999999999"}, I am unable to get this to work.
Apart from that, how can I print the Request "Headers" along with "Query params"? Thank you in advance
I think you need to encode the value inputs, something like this:
webTarget.queryParam("searchCondition", URLEncoder.encode("{mobileNo=\"+919999999999\"}", StandardCharsets.UTF_8.toString()));
UDPATE:
Example of the rest client with Spring:
#Test
public void testStack() throws Exception {
RestTemplate rest = new RestTemplate();
String fooResourceUrl="http://localhost:8080/usersParam?";
RestTemplate restTemplate = new RestTemplate();
String parameter = "{mobileNo=\"+919999999999\"}";
ResponseEntity<String> response = restTemplate.getForEntity(fooResourceUrl + "parameter=" + URLEncoder.encode(parameter, StandardCharsets.UTF_8.toString() ), String.class);
assertThat(response.getStatusCode()).isEqualTo(HttpStatus.OK);
}
And this would be the rest service:
#RequestMapping(method = RequestMethod.GET, value="/usersParam")
public User getUsersInfo(#RequestParam String parameter) throws UnsupportedEncodingException {
System.out.println(URLDecoder.decode(parameter, StandardCharsets.UTF_8.toString() ));
return null;
}

Pusher Invalid signature: Expected HMAC SHA256 hex digest of

I have JavaScript code in one HTML file from which I am calling server for authentication:
<html>
<script>
<head>
var options = { authEndpoint: "api/pusher.json?socket_id=9900&channel_name=presence-channel" }
var pusher = new Pusher('98384343434343434', options);
pusher.connection.bind('connected', function() {
console.log("connected");
socketId = pusher.connection.socket_id;
console.log("socketId" + socketId);
});
var channel = pusher.subscribe('presence-channel');
</script>
</head>
<body></body>
</html>
And on the server the code is as below:
import com.pusher.rest.Pusher;
import com.pusher.rest.data.PresenceUser;
import com.webapp.actions.BusinessApiAction;
#Path("/api/pusher")
public class PusherAction extends BusinessApiAction {
#POST
#Produces({ "application/Json", "application/xml" })
public Response pusher(#Context ServletContext context, #Context HttpServletRequest req, #Context HttpServletResponse res, #FormParam("socket_id") String socketId, #FormParam("channel_name") String channelName) throws Exception {
System.out.println("\n\n===channel==> " + channelName + "\t socket id-->" + socketId);
Pusher pusher = new Pusher("92063", "3055e2b132174078348c", "52cfe6c7ecb8420ad981");
String userId = "5433d5da97d88628ec000300";
Map<String, String> userInfo = new HashMap<>();
userInfo.put("name", "Phil Leggetter");
String authBody = pusher.authenticate(socketId, channelName, new PresenceUser(userId, userInfo));
JSONObject j = new JSONObject(authBody);
System.out.println("\n\n===authBody==> " + j.getString("auth"));
Map<String, Object> map = new HashMap<>();
Map<String, Object> channelData = new HashMap<>();
map.put("auth", j.getString("auth"));
JSONObject ch = new JSONObject(j.getString("channel_data"));
channelData.put("user_id", ch.getString("user_id"));
channelData.put("user_info", userInfo);
map.put("channel_data", ch.toString());
return sendDataResponse(map);
}
}
The returned response is 200 but Pusher is giving this error:
Error in the pusher logger--
Pusher : Event sent : {"event":"pusher:subscribe","data":{"auth":"3055e2b132174078348c:980bf9a6d3a61d280d181785ccacd0e5e7999776085403f2d9bfe688842b8fe7","channel_data":"{\"user_info\":{\"name\":\"Phil Leggetter\"},\"user_id\":\"5433d5da97d88628ec000300\"}","channel":"presence-user2"}}
Pusher : Event recd : {"event":"pusher:error","data":{"code":null,"message":"Invalid signature: Expected HMAC SHA256 hex digest of 41797.10543542:presence-user2:{\"user_info\":{\"name\":\"Phil Leggetter\"},\"user_id\":\"5433d5da97d88628ec000300\"}, but got 980bf9a6d3a61d280d181785ccacd0e5e7999776085403f2d9bfe688842b8fe7"}}
Pusher : Error : {"type":"WebSocketError","error":{"type":"PusherError","data":{"code":null,"message":"Invalid signature: Expected HMAC SHA256 hex digest of 41797.10543542:presence-user2:{\"user_info\":{\"name\":\"Phil Leggetter\"},\"user_id\":\"5433d5da97d88628ec000300\"}, but got 980bf9a6d3a61d280d181785ccacd0e5e7999776085403f2d9bfe688842b8fe7"}}}
The authBody that is returned from pusher.authenticate should provide you with everything you need to respond to the client request. You just need to make sure that sendDataResponse send the authBody back as the body of the response as JSON.
I've updated the example you've provided to remove the lines that aren't required:
#Path("/api/pusher")
public class PusherAction extends BusinessApiAction {
#POST
#Produces({ "application/Json", "application/xml" })
public Response pusher(#Context ServletContext context, #Context HttpServletRequest req, #Context HttpServletResponse res, #FormParam("socket_id") String socketId, #FormParam("channel_name") String channelName) throws Exception {
System.out.println("\n\n===channel==> " + channelName + "\t socket id-->" + socketId);
Pusher pusher = new Pusher(APP_ID, APP_KEY, APP_SECRET);
String userId = "5433d5da97d88628ec000300";
Map<String, String> userInfo = new HashMap<>();
userInfo.put("name", "Phil Leggetter");
String authBody = pusher.authenticate(socketId, channelName, new PresenceUser(userId, userInfo));
return sendDataResponse(authBody);
}
}
The pusher-rest-java library README show the additional functionality that was present isn't required:
https://github.com/pusher/pusher-rest-java#authenticating-presence-channels

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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