Related
I'm using RestTemplate to call my webservice's health actuator endpoint from another webservice of mine to see if the webservice is up. If the webservice is up, all works fine, but when it's down, I get an error 500, "Internal Server Error". If my webservice is down, I'm trying to catch that error to be able to handle it, but the problem I'm having is that I can't seem to be able to catch the error.
I've tried the following and it never enters either of my catch sections
#Service
public class DepositService {
#Bean
public RestTemplate restTemplate(RestTemplateBuilder builder) {
return builder
.setConnectTimeout(Duration.ofMillis(3000))
.setReadTimeout(Duration.ofMillis(3000))
.build();
}
private static void getBankAccountConnectorHealth() {
final String uri = "http://localhost:9996/health";
RestTemplate restTemplate = new RestTemplate();
String result = null;
try {
result = restTemplate.getForObject(uri, String.class);
} catch (HttpClientErrorException exception) {
System.out.println("callToRestService Error :" + exception.getResponseBodyAsString());
} catch (HttpStatusCodeException exception) {
System.out.println( "callToRestService Error :" + exception.getResponseBodyAsString());
}
System.out.println(result);
}
}
I've also tried doing it this way, but same results. It never seems to enter my error handler class.
public class NotFoundException extends RuntimeException {
}
public class RestTemplateResponseErrorHandler implements ResponseErrorHandler {
#Override
public boolean hasError(ClientHttpResponse httpResponse) throws IOException {
return (httpResponse.getStatusCode().series() == CLIENT_ERROR || httpResponse.getStatusCode().series() == SERVER_ERROR);
}
#Override
public void handleError(ClientHttpResponse httpResponse) throws IOException {
if (httpResponse.getStatusCode().series() == HttpStatus.Series.SERVER_ERROR) {
// handle SERVER_ERROR
System.out.println("Server error!");
} else if (httpResponse.getStatusCode().series() == HttpStatus.Series.CLIENT_ERROR) {
// handle CLIENT_ERROR
System.out.println("Client error!");
if (httpResponse.getStatusCode() == HttpStatus.NOT_FOUND) {
throw new NotFoundException();
}
}
}
}
#Service
public class DepositService {
#Bean
public RestTemplate restTemplate(RestTemplateBuilder builder) {
return builder
.setConnectTimeout(Duration.ofMillis(3000))
.setReadTimeout(Duration.ofMillis(3000))
.build();
}
private static void getAccountHealth() {
final String uri = "http://localhost:9996/health";
RestTemplate restTemplate = new RestTemplate();
restTemplate.setErrorHandler(new RestTemplateResponseErrorHandler());
String result = null;
result = restTemplate.getForObject(uri, String.class);
System.out.println(result);
}
}
Any suggestions as to how I can call my webservice's health actuator from another webservice and catch if that webservice is down?
It looks like the getForObject doesn't throw either of the exceptions you are catching. From the documentation, it throws RestClientException. The best method I have found for identifying thrown exceptions is to catch Exception in the debugger and inspect it to find out if it's useful.
With the second method, I'm not sure why you would create a bean method for the RestTemplate and then create one with new. You probably should inject your RestTemplate and initialise the ResponseErrorHandler with the RestTemplateBuilder::errorHandler method.
Internal serve error throw HttpServerErrorException You should catch this exception if you want to handle it However the better way to do that is using error handler you can see the following posts to see how to do that:
spring-rest-template-error-handling
spring-boot-resttemplate-error-handling
Is there anyway to force spring to always produce json, even an empty json object if there's no data to return.
Our services go through another service that rejects any response that isn't valid json (regardless of status code). It's not nice but we have no control of this.
With spring controllers you can tell them to produce json, but this only works when there's content to return. Is there a quick and elegant way to make all responses be json?
#RequestMapping(value = "/test", method = RequestMethod.GET, produces = MediaType.APPLICATION_JSON_VALUE)
public
#ResponseBody
ResponseEntity<String> test(){
// if this returns null or an empty string the response body will be emtpy
// and the content-type header will not be set.
return service.getData();
}
The simply fix here is to simply add an if statement to check for null. But that's ugly as I'll have to manually set the header and the response body.
I'm hoping someone knows of a nicer way?
Thanks
If you want all responses to return application/json, then you can set this at a single place by overriding postHandle() from HandlerInterceptorAdapter:
#Component
public class ResponseInterceptor extends HandlerInterceptorAdapter {
#Override
public void postHandle(final HttpServletRequest request, final HttpServletResponse response, final Object handler,
final ModelAndView modelAndView) throws IOException {
if (response.getContentType() == null || response.getContentType().equals("")) {
response.setContentType("application/json");
}
}
}
You can look here
You may wrap the response in a "Container" object
For example I use this BaseAjaxResponse:
public class BaseAjaxResponse implements Serializable
{
private static final long serialVersionUID = 9087132709920851138L;
private int codiceOperazione;
private String descrizioneEsitoOperazione;
private long numeroTotaleOggetti;
private long numeroOggettiRestituiti;
private List<? extends Object> payload;
//Constructors and getter/setter
}
Then in my controllers I use this strategy:
#RequestMapping(method = { RequestMethod.POST }, value = { "/find" })
public ResponseEntity<BaseAjaxResponse> createCandidato(#RequestBody CandidatoDto candidato){
BaseAjaxResponse bar = new BaseAjaxResponse();
HttpStatus statusCode = null;
List<Object> payload = null;
StopWatch sw = new StopWatch("Find");
try
{
sw.start();
payload = myService.find();
sw.stop();
if( payload == null || payload.isEmpty() )
{
statusCode = HttpStatus.NO_CONTENT;
bar.setCodiceOperazione(statusCode.value());
bar.setDescrizioneEsitoOperazione("No result");
}
else
{
statusCode = HttpStatus.OK;
bar.setCodiceOperazione(statusCode.value());
bar.setDescrizioneEsitoOperazione("Got result");
//Set the object count and the number of found objects
}
}
catch (Exception e)
{
String message = "Errore nell'inserimento di un candidato; "+e.getMessage();
statusCode = HttpStatus.INTERNAL_SERVER_ERROR;
bar.setCodiceOperazione(statusCode.value());
bar.setDescrizioneEsitoOperazione(message);
logger.error(message, e);
}
finally
{
if( sw.isRunning() )
{
sw.stop();
if( logger.isDebugEnabled() )
{
logger.debug("CHIUSURA STOPWATCH FORZATA. "+sw.toString());
}
}
}
return new ResponseEntity<BaseAjaxResponse>(bar, statusCode);
}
I hope this can be useful
Angelo
I have a scenario in Zuul where the service that the URL is routed too might be down . So the reponse body gets thrown with 500 HTTP Status and ZuulException in the JSON body response.
{
"timestamp": 1459973637928,
"status": 500,
"error": "Internal Server Error",
"exception": "com.netflix.zuul.exception.ZuulException",
"message": "Forwarding error"
}
All I want to do is to customise or remove the JSON response and maybe change the HTTP status Code.
I tried to create a exception Handler with #ControllerAdvice but the exception is not grabbed by the handler.
UPDATES:
So I extended the Zuul Filter I can see it getting into the run method after the error has been executed how do i change the response then. Below is what i got so far. I read somewhere about SendErrorFilter but how do i implement that and what does it do?
public class CustomFilter extends ZuulFilter {
#Override
public String filterType() {
return "post";
}
#Override
public int filterOrder() {
return 1;
}
#Override
public boolean shouldFilter() {
return true;
}
#Override
public Object run() {
final RequestContext ctx = RequestContext.getCurrentContext();
final HttpServletResponse response = ctx.getResponse();
if (HttpStatus.INTERNAL_SERVER_ERROR.value() == ctx.getResponse().getStatus()) {
try {
response.sendError(404, "Error Error"); //trying to change the response will need to throw a JSON body.
} catch (final IOException e) {
e.printStackTrace();
} ;
}
return null;
}
Added this to the class that has #EnableZuulProxy
#Bean
public CustomFilter customFilter() {
return new CustomFilter();
}
We finally got this working [Coded by one of my colleague]:-
public class CustomErrorFilter extends ZuulFilter {
private static final Logger LOG = LoggerFactory.getLogger(CustomErrorFilter.class);
#Override
public String filterType() {
return "post";
}
#Override
public int filterOrder() {
return -1; // Needs to run before SendErrorFilter which has filterOrder == 0
}
#Override
public boolean shouldFilter() {
// only forward to errorPath if it hasn't been forwarded to already
return RequestContext.getCurrentContext().containsKey("error.status_code");
}
#Override
public Object run() {
try {
RequestContext ctx = RequestContext.getCurrentContext();
Object e = ctx.get("error.exception");
if (e != null && e instanceof ZuulException) {
ZuulException zuulException = (ZuulException)e;
LOG.error("Zuul failure detected: " + zuulException.getMessage(), zuulException);
// Remove error code to prevent further error handling in follow up filters
ctx.remove("error.status_code");
// Populate context with new response values
ctx.setResponseBody(“Overriding Zuul Exception Body”);
ctx.getResponse().setContentType("application/json");
ctx.setResponseStatusCode(500); //Can set any error code as excepted
}
}
catch (Exception ex) {
LOG.error("Exception filtering in custom error filter", ex);
ReflectionUtils.rethrowRuntimeException(ex);
}
return null;
}
}
The Zuul RequestContext doesn't contain the error.exception as mentioned in this answer.
Up to date the Zuul error filter:
#Component
public class ErrorFilter extends ZuulFilter {
private static final Logger LOG = LoggerFactory.getLogger(ErrorFilter.class);
private static final String FILTER_TYPE = "error";
private static final String THROWABLE_KEY = "throwable";
private static final int FILTER_ORDER = -1;
#Override
public String filterType() {
return FILTER_TYPE;
}
#Override
public int filterOrder() {
return FILTER_ORDER;
}
#Override
public boolean shouldFilter() {
return true;
}
#Override
public Object run() {
final RequestContext context = RequestContext.getCurrentContext();
final Object throwable = context.get(THROWABLE_KEY);
if (throwable instanceof ZuulException) {
final ZuulException zuulException = (ZuulException) throwable;
LOG.error("Zuul failure detected: " + zuulException.getMessage());
// remove error code to prevent further error handling in follow up filters
context.remove(THROWABLE_KEY);
// populate context with new response values
context.setResponseBody("Overriding Zuul Exception Body");
context.getResponse().setContentType("application/json");
// can set any error code as excepted
context.setResponseStatusCode(503);
}
return null;
}
}
I had the same problem and was able to solve it in simpler way
Just put this into you Filter run() method
if (<your condition>) {
ZuulException zuulException = new ZuulException("User message", statusCode, "Error Details message");
throw new ZuulRuntimeException(zuulException);
}
and SendErrorFilter will deliver to the user the message with the desired statusCode.
This Exception in an Exception pattern does not look exactly nice, but it works here.
Forwarding is often done by a filter, in this case the request does not even reach a controller. This would explain why your #ControllerAdvice does not work.
If you forward in the controller than the #ControllerAdvice should work.
Check if spring creates an instance of the class annotated with #ControllerAdvice. For that place a breakpoint in the class and see whether it is hit.
Add a breakpoint also in the controller method where the forwarding should happen. May be you accidently invoke another controller method than you inspect ?
These steps should help you resolve the issue.
In your class annotated with #ControllerAdvice add an ExceptionHandler method annotated with #ExceptionHandler(Exception.class), that should catch every Exception.
EDIT :
You can try to add your own filter that converts the error response returned by the Zuulfilter. There you can change the response as you like.
How the error response can be customized is explained here :
exception handling for filter in spring
Placing the filter correctly may be a little tricky.
Not exactly sure about the correct position, but you should be aware of the order of your filters and the place where you handle the exception.
If you place it before the Zuulfilter, you have to code your error handling after calling doFilter().
If you place it after the Zuulfilter, you have to code your error handling before calling doFilter().
Add breakpoints in your filter before and after doFilter() may help to find the correct position.
Here are the steps to do it with #ControllerAdvice:
First add a filter of type error and let it be run before the SendErrorFilter in zuul itself.
Make sure to remove the key associated with the exception from the RequestContext to prevent the SendErrorFilter from executing.
Use RequestDispatcher to forward the request to the ErrorController -- explained below.
Add a #RestController class and make it extends AbstractErrorController, and re-throw the exception again (add it in the step of executing your new error filter with (key, exception), get it from the RequestContext in your controller).
The exception will now be caught in your #ControllerAdvice class.
The simplest solution is to follow first 4 steps.
1. Create your own CustomErrorController extends
AbstractErrorController which will not allow the
BasicErrorController to be called.
2. Customize according to your need refer below method from
BasicErrorController.
<pre><code>
#RequestMapping
public ResponseEntity<Map<String, Object>> error(HttpServletRequest request) {
Map<String, Object> body = getErrorAttributes(request,
isIncludeStackTrace(request, MediaType.ALL));
HttpStatus status = getStatus(request);
return new ResponseEntity<>(body, status);
}
</pre></code>
4. You can control whether you want exception / stack trace to be printed or not can do as mentioned below:
<pre><code>
server.error.includeException=false
server.error.includeStacktrace=ON_TRACE_PARAM
</pre></code>
====================================================
5. If you want all together different error response re-throw your custom exception from your CustomErrorController and implement the Advice class as mentioned below:
<pre><code>
#Controller
#Slf4j
public class CustomErrorController extends BasicErrorController {
public CustomErrorController(ErrorAttributes errorAttributes, ServerProperties serverProperties,
List<ErrorViewResolver> errorViewResolvers) {
super(errorAttributes, serverProperties.getError(), errorViewResolvers);
log.info("Created");
}
#Override
public ResponseEntity<Map<String, Object>> error(HttpServletRequest request) {
Map<String, Object> body = getErrorAttributes(request, isIncludeStackTrace(request, MediaType.ALL));
HttpStatus status = getStatus(request);
throw new CustomErrorException(String.valueOf(status.value()), status.getReasonPhrase(), body);
}
}
#ControllerAdvice
public class GenericExceptionHandler {
// Exception handler annotation invokes a method when a specific exception
// occurs. Here we have invoked Exception.class since we
// don't have a specific exception scenario.
#ExceptionHandler(CustomException.class)
#ResponseBody
public ErrorListWsDTO customExceptionHandle(
final HttpServletRequest request,
final HttpServletResponse response,
final CustomException exception) {
LOG.info("Exception Handler invoked");
ErrorListWsDTO errorData = null;
errorData = prepareResponse(response, exception);
response.setStatus(Integer.parseInt(exception.getCode()));
return errorData;
}
/**
* Prepare error response for BAD Request
*
* #param response
* #param exception
* #return
*/
private ErrorListWsDTO prepareResponse(final HttpServletResponse response,
final AbstractException exception) {
final ErrorListWsDTO errorListData = new ErrorListWsDTO();
final List<ErrorWsDTO> errorList = new ArrayList<>();
response.setStatus(HttpStatus.BAD_REQUEST.value());
final ErrorWsDTO errorData = prepareErrorData("500",
"FAILURE", exception.getCause().getMessage());
errorList.add(errorData);
errorListData.setErrors(errorList);
return errorListData;
}
/**
* This method is used to prepare error data
*
* #param code
* error code
* #param status
* status can be success or failure
* #param exceptionMsg
* message description
* #return ErrorDTO
*/
private ErrorWsDTO prepareErrorData(final String code, final String status,
final String exceptionMsg) {
final ErrorWsDTO errorDTO = new ErrorWsDTO();
errorDTO.setReason(code);
errorDTO.setType(status);
errorDTO.setMessage(exceptionMsg);
return errorDTO;
}
}
</pre></code>
This is what worked for me. RestExceptionResponse is the class which is used within the #ControllerAdvice, so we have an identical exception response in case of internal ZuulExceptions.
#Component
#Log4j
public class CustomZuulErrorFilter extends ZuulFilter {
private static final String SEND_ERROR_FILTER_RAN = "sendErrorFilter.ran";
#Override
public String filterType() {
return ERROR_TYPE;
}
#Override
public int filterOrder() {
return SEND_ERROR_FILTER_ORDER - 1; // Needs to run before SendErrorFilter which has filterOrder == 0
}
#Override
public boolean shouldFilter() {
RequestContext ctx = RequestContext.getCurrentContext();
Throwable ex = ctx.getThrowable();
return ex instanceof ZuulException && !ctx.getBoolean(SEND_ERROR_FILTER_RAN, false);
}
#Override
public Object run() {
try {
RequestContext ctx = RequestContext.getCurrentContext();
ZuulException ex = (ZuulException) ctx.getThrowable();
// log this as error
log.error(StackTracer.toString(ex));
String requestUri = ctx.containsKey(REQUEST_URI_KEY) ? ctx.get(REQUEST_URI_KEY).toString() : "/";
RestExceptionResponse exceptionResponse = new RestExceptionResponse(HttpStatus.INTERNAL_SERVER_ERROR, ex, requestUri);
// Populate context with new response values
ctx.setResponseStatusCode(500);
this.writeResponseBody(ctx.getResponse(), exceptionResponse);
ctx.set(SEND_ERROR_FILTER_RAN, true);
}
catch (Exception ex) {
log.error(StackTracer.toString(ex));
ReflectionUtils.rethrowRuntimeException(ex);
}
return null;
}
private void writeResponseBody(HttpServletResponse response, Object body) throws IOException {
response.setContentType("application/json");
try (PrintWriter writer = response.getWriter()) {
writer.println(new JSonSerializer().toJson(body));
}
}
}
The output looks like this:
{
"timestamp": "2020-08-10 16:18:16.820",
"status": 500,
"error": "Internal Server Error",
"path": "/service",
"exception": {
"message": "Filter threw Exception",
"exceptionClass": "com.netflix.zuul.exception.ZuulException",
"superClasses": [
"com.netflix.zuul.exception.ZuulException",
"java.lang.Exception",
"java.lang.Throwable",
"java.lang.Object"
],
"stackTrace": null,
"cause": {
"message": "com.netflix.zuul.exception.ZuulException: Forwarding error",
"exceptionClass": "org.springframework.cloud.netflix.zuul.util.ZuulRuntimeException",
"superClasses": [
"org.springframework.cloud.netflix.zuul.util.ZuulRuntimeException",
"java.lang.RuntimeException",
"java.lang.Exception",
"java.lang.Throwable",
"java.lang.Object"
],
"stackTrace": null,
"cause": {
"message": "Forwarding error",
"exceptionClass": "com.netflix.zuul.exception.ZuulException",
"superClasses": [
"com.netflix.zuul.exception.ZuulException",
"java.lang.Exception",
"java.lang.Throwable",
"java.lang.Object"
],
"stackTrace": null,
"cause": {
"message": "Load balancer does not have available server for client: template-scalable-service",
"exceptionClass": "com.netflix.client.ClientException",
"superClasses": [
"com.netflix.client.ClientException",
"java.lang.Exception",
"java.lang.Throwable",
"java.lang.Object"
],
"stackTrace": null,
"cause": null
}
}
}
}
}
i have implemented rest webservices using Jersey, and whenever some exception occur on the server side, the client gets a generic HTTP 500 Internal Server Error, with no more info of the real exception. I found that people usually catch any exception on the server side, then throws a WebApplicationException, but even this way the client keeps getting the generic HTTP 500 Internal Server Error.
This is my webservice:
#PUT
#Produces(MediaType.APPLICATION_XML)
#Consumes(MediaType.APPLICATION_XML)
#Path("/transmitir")
public WrapperTransmissaoRetorno receber(WrapperTransmissao wrapperRecepcao) {
WrapperTransmissaoRetorno retorno = new WrapperTransmissaoRetorno();
retorno.setCodigoMaster(new Random().nextInt());
retorno.setDataRetorno(new Date());
if(true){
throw new WebApplicationException("Este pau eh bem graudo");
}
return retorno;
}
This is the code that calls the client:
try {
WsTransmissaoCliente client = new WsTransmissaoCliente();
WrapperTransmissao wrapperRecepcao = new WrapperTransmissao();
Transferencia transferencia = new Transferencia();
transferencia.setCodigoTabela(23);
transferencia.setCodigoTransferencia(56);
transferencia.setDataRetorno(new Date());
transferencia.setDataTransmissao(new Date(System.currentTimeMillis()+3000000));
transferencia.setNomeTabela("CUPOM");
transferencia.setTipoOperacao(TipoOperacao.UPDATE);
wrapperRecepcao.setTransferencia(transferencia);
Jumento jumento = new Jumento();
jumento.setIdade(24);
jumento.setNome("José");
wrapperRecepcao.setObjeto(jumento);
// Cabrito cabrito = new Cabrito();
// cabrito.setAltura(56);
// cabrito.setPeso(120.0);
// wrapperRecepcao.setObjeto(cabrito);
WrapperTransmissaoRetorno retorno = client.transmitir(wrapperRecepcao);
System.out.println("Retorno do WS: "+retorno);
} catch (Exception e) {
WebApplicationException exx = (WebApplicationException) e;
exx.printStackTrace();
}
How to avoid this and get the real exception? Or at least the message?
UPDATE
Here is the object i am sending as a response:
package br.atualy.integracaocheckout.wrappers;
import java.util.Date;
import javax.xml.bind.annotation.XmlRootElement;
#XmlRootElement
public class WrapperTransmissaoRetorno {
private Date dataRetorno;
private Integer codigoMaster;
public Date getDataRetorno() {
return dataRetorno;
}
public void setDataRetorno(Date dataRetorno) {
this.dataRetorno = dataRetorno;
}
public Integer getCodigoMaster() {
return codigoMaster;
}
public void setCodigoMaster(Integer codigoMaster) {
this.codigoMaster = codigoMaster;
}
#Override
public String toString() {
return "WrapperRecepcaoRetorno{" + "dataRetorno=" + dataRetorno + ", codigoMaster=" + codigoMaster + '}';
}
}
UPDATE 2
And here is the client:
import br.atualy.integracaocheckout.wrappers.WrapperTransmissao;
import br.atualy.integracaocheckout.wrappers.WrapperTransmissaoRetorno;
import javax.ws.rs.ClientErrorException;
import javax.ws.rs.client.Client;
import javax.ws.rs.client.WebTarget;
public class WsTransmissaoCliente {
private final WebTarget webTarget;
private final Client client;
private static final String BASE_URI = "http://localhost:8080/IntegracaoCheckout/webresources";
public WsTransmissaoCliente() {
client = javax.ws.rs.client.ClientBuilder.newClient();
webTarget = client.target(BASE_URI).path("transmissao");
}
// public String receber() throws ClientErrorException {
// WebTarget resource = webTarget;
// resource = resource.path("receber");
// return resource.request(javax.ws.rs.core.MediaType.APPLICATION_XML).get(String.class);
// }
public WrapperTransmissaoRetorno transmitir(WrapperTransmissao requestEntity) throws ClientErrorException {
return webTarget.path("transmitir")
.request(javax.ws.rs.core.MediaType.APPLICATION_XML)
.put(javax.ws.rs.client.Entity.entity(requestEntity, javax.ws.rs.core.MediaType.APPLICATION_XML), WrapperTransmissaoRetorno.class);
}
public void close() {
client.close();
}
}
If using jawax.ws.rs.core.Response object.
SERVER :: In case of exception/failure set it as :
// do stuff
// here e.getMessage() can be custom failure message too
response = Response.serverError().entity(e.getMessage()).build();
// return response object
return response;
CLIENT :: On the client side check following :
if(response != null && reponse.getStatus() == Response.Status.INTERNAL_SERVER_ERROR.getStatusCode()) {
String serverErrorMsg = response.readEntity(String.class);
throw new Exception(serverErrorMsg);
}
Generally it's better to declare your method as returning a Response object instead of a user-defined type, and set the data as the entity. Then if you want to indicate that an exception has happened, you can just pass that exception as the entity of the Response you are returning.
e.g.
#GET
#Path("/foo")
public Response getFoo() {
try {
// do stuff
return Response.ok(someData).build();
} catch (Exception e) {
return Response.serverError().entity(e).build();
}
}
You'll notice that this way you don't ever end up actually throwing an exception out of your method, but rather return an explicit 500 response with an exception as the entity. This way you can still throw exceptions out of your code, but they'll be handled nicely.
EDIT
I'm not sure what your client wrapper code is doing, but you can pass the expected response data type into your call with the normal REST client:
Client client = ClientBuilder.newClient();
WebTarget target = client.target("http://foo.com/foo");
String response = target.request().get(String.class);
or you can also pull it out of the Response using the readEntity() method:
Client client = ClientBuilder.newClient();
WebTarget target = client.target("http://foo.com/foo");
Response response = target.request().get();
String entity = response.readEntity(String.class);
It sounds like what you need to do is check the return code, and then parse the entity as a either a WrapperTransmissaoRetorno or a WebApplicationException depending on what code was returned:
Response response = client.transmitir(wrapperRecepcao);
if (response.getStatus() == Response.Status.OK.getStatusCode()) { // 200
WrapperTransmissaoRetorno retorno = response.readEntity(WrapperTransmissaoRetorno.class);
// do stuff
} else if (response.getStatus() == Response.Status.INTERNAL_SERVER_ERROR.getStatusCode()) { // 500
WebApplicationException e = response.readEntity(WebApplicationException.class);
// do stuff
} // etc for other response codes
Use response object in webapplication excemption. It should work.
From java docs:
WebApplicationException(String message)
Construct a new instance with a blank message and default HTTP status code of 500.
Its a blank message. I haven't tried it myself. I guess this is the problem.
https://jersey.java.net/apidocs/2.6/jersey/javax/ws/rs/WebApplicationException.html
Even after all the suggestions i could not manage to throw the exception to the client.
So what i did was to put a String property inside my returning class, so when an exception occurs on the server side, this String will contain the exception message and i can get it on the client.
I am starting to use the new client API library in JAX-RS and really loving it so far. I have found one thing I cannot figure out however. The API I am using has a custom error message format that looks like this for example:
{
"code": 400,
"message": "This is a message which describes why there was a code 400."
}
It returns 400 as the status code but also includes a descriptive error message to tell you what you did wrong.
However the JAX-RS 2.0 client is re-mapping the 400 status into something generic and I lose the good error message. It correctly maps it to a BadRequestException, but with a generic "HTTP 400 Bad Request" message.
javax.ws.rs.BadRequestException: HTTP 400 Bad Request
at org.glassfish.jersey.client.JerseyInvocation.convertToException(JerseyInvocation.java:908)
at org.glassfish.jersey.client.JerseyInvocation.translate(JerseyInvocation.java:770)
at org.glassfish.jersey.client.JerseyInvocation.access$500(JerseyInvocation.java:90)
at org.glassfish.jersey.client.JerseyInvocation$2.call(JerseyInvocation.java:671)
at org.glassfish.jersey.internal.Errors.process(Errors.java:315)
at org.glassfish.jersey.internal.Errors.process(Errors.java:297)
at org.glassfish.jersey.internal.Errors.process(Errors.java:228)
at org.glassfish.jersey.process.internal.RequestScope.runInScope(RequestScope.java:424)
at org.glassfish.jersey.client.JerseyInvocation.invoke(JerseyInvocation.java:667)
at org.glassfish.jersey.client.JerseyInvocation$Builder.method(JerseyInvocation.java:396)
at org.glassfish.jersey.client.JerseyInvocation$Builder.get(JerseyInvocation.java:296)
Is there some sort of interceptor or custom error handler that can be injected so that I get access to the real error message. I've been looking through documentation but can't see any way of doing it.
I am using Jersey right now, but I tried this using CXF and got the same result. Here is what the code looks like.
Client client = ClientBuilder.newClient().register(JacksonFeature.class).register(GzipInterceptor.class);
WebTarget target = client.target("https://somesite.com").path("/api/test");
Invocation.Builder builder = target.request()
.header("some_header", value)
.accept(MediaType.APPLICATION_JSON_TYPE)
.acceptEncoding("gzip");
MyEntity entity = builder.get(MyEntity.class);
UPDATE:
I implemented the solution listed in the comment below. It is slightly different since the classes have changed a bit in the JAX-RS 2.0 client API. I still think it is wrong that the default behavior is to give a generic error message and discard the real one. I understand why it wouldn't parse my error object, but the un-parsed version should have been returned. I end up having the replicate exception mapping that the library already does.
Thanks for the help.
Here is my filter class:
#Provider
public class ErrorResponseFilter implements ClientResponseFilter {
private static ObjectMapper _MAPPER = new ObjectMapper();
#Override
public void filter(ClientRequestContext requestContext, ClientResponseContext responseContext) throws IOException {
// for non-200 response, deal with the custom error messages
if (responseContext.getStatus() != Response.Status.OK.getStatusCode()) {
if (responseContext.hasEntity()) {
// get the "real" error message
ErrorResponse error = _MAPPER.readValue(responseContext.getEntityStream(), ErrorResponse.class);
String message = error.getMessage();
Response.Status status = Response.Status.fromStatusCode(responseContext.getStatus());
WebApplicationException webAppException;
switch (status) {
case BAD_REQUEST:
webAppException = new BadRequestException(message);
break;
case UNAUTHORIZED:
webAppException = new NotAuthorizedException(message);
break;
case FORBIDDEN:
webAppException = new ForbiddenException(message);
break;
case NOT_FOUND:
webAppException = new NotFoundException(message);
break;
case METHOD_NOT_ALLOWED:
webAppException = new NotAllowedException(message);
break;
case NOT_ACCEPTABLE:
webAppException = new NotAcceptableException(message);
break;
case UNSUPPORTED_MEDIA_TYPE:
webAppException = new NotSupportedException(message);
break;
case INTERNAL_SERVER_ERROR:
webAppException = new InternalServerErrorException(message);
break;
case SERVICE_UNAVAILABLE:
webAppException = new ServiceUnavailableException(message);
break;
default:
webAppException = new WebApplicationException(message);
}
throw webAppException;
}
}
}
}
I believe you want to do something like this:
Response response = builder.get( Response.class );
if ( response.getStatusCode() != Response.Status.OK.getStatusCode() ) {
System.out.println( response.getStatusType() );
return null;
}
return response.readEntity( MyEntity.class );
Another thing you can try (since I don't know where this API puts stuff -- i.e. in the header or entity or what) is:
Response response = builder.get( Response.class );
if ( response.getStatusCode() != Response.Status.OK.getStatusCode() ) {
// if they put the custom error stuff in the entity
System.out.println( response.readEntity( String.class ) );
return null;
}
return response.readEntity( MyEntity.class );
If you would like to generally map REST response codes to Java exception you can add a client filter to do that:
class ClientResponseLoggingFilter implements ClientResponseFilter {
#Override
public void filter(final ClientRequestContext reqCtx,
final ClientResponseContext resCtx) throws IOException {
if ( resCtx.getStatus() == Response.Status.BAD_REQUEST.getStatusCode() ) {
throw new MyClientException( resCtx.getStatusInfo() );
}
...
In the above filter you can create specific exceptions for each code or create one generic exception type that wraps the Response code and entity.
There are other ways to getting a custom error message to the Jersey client besides writing a custom filter. (although the filter is an excellent solution)
1) Pass error message in an HTTP header field.
The detail error message could be in the JSON response and in an additional header field, such as "x-error-message".
The Server adds the HTTP error header.
ResponseBuilder rb = Response.status(respCode.getCode()).entity(resp);
if (!StringUtils.isEmpty(errMsg)){
rb.header("x-error-message", errMsg);
}
return rb.build();
The Client catches the exception, NotFoundException in my case, and reads the response header.
try {
Integer accountId = 2222;
Client client = ClientBuilder.newClient();
WebTarget webTarget = client.target("http://localhost:8080/rest-jersey/rest");
webTarget = webTarget.path("/accounts/"+ accountId);
Invocation.Builder ib = webTarget.request(MediaType.APPLICATION_JSON);
Account resp = ib.get(new GenericType<Account>() {
});
} catch (NotFoundException e) {
String errorMsg = e.getResponse().getHeaderString("x-error-message");
// do whatever ...
return;
}
2) Another solution is to catch the exception and read the response content.
try {
// same as above ...
} catch (NotFoundException e) {
String respString = e.getResponse().readEntity(String.class);
// you can convert to JSON or search for error message in String ...
return;
}
The class WebApplicationException was designed for that but for some reason it ignores and overwrites what you specify as parameter for the message.
For that reason I created my own extension WebAppException that honors the parameters. It is a single class and it doesn't require any response filter or a mapper.
I prefer exceptions than creating a Response as it can be thrown from anywhere while processing.
Simple usage:
throw new WebAppException(Status.BAD_REQUEST, "Field 'name' is missing.");
The class:
import javax.ws.rs.WebApplicationException;
import javax.ws.rs.core.Response;
import javax.ws.rs.core.Response.Status;
import javax.ws.rs.core.Response.Status.Family;
import javax.ws.rs.core.Response.StatusType;
public class WebAppException extends WebApplicationException {
private static final long serialVersionUID = -9079411854450419091L;
public static class MyStatus implements StatusType {
final int statusCode;
final String reasonPhrase;
public MyStatus(int statusCode, String reasonPhrase) {
this.statusCode = statusCode;
this.reasonPhrase = reasonPhrase;
}
#Override
public int getStatusCode() {
return statusCode;
}
#Override
public Family getFamily() {
return Family.familyOf(statusCode);
}
#Override
public String getReasonPhrase() {
return reasonPhrase;
}
}
public WebAppException() {
}
public WebAppException(int status) {
super(status);
}
public WebAppException(Response response) {
super(response);
}
public WebAppException(Status status) {
super(status);
}
public WebAppException(String message, Response response) {
super(message, response);
}
public WebAppException(int status, String message) {
super(message, Response.status(new MyStatus(status, message)). build());
}
public WebAppException(Status status, String message) {
this(status.getStatusCode(), message);
}
public WebAppException(String message) {
this(500, message);
}
}
A much more concise solution for anyone stumbling on this:
Calling .get(Class<T> responseType) or any of the other methods that take the result type as an argument Invocation.Builder will return a value of the desired type instead of a Response. As a side effect, these methods will check if the received status code is in the 2xx range and throw an appropriate WebApplicationException otherwise.
From the documentation:
Throws: WebApplicationException in case the response status code of
the response returned by the server is not successful and the
specified response type is not Response.
This allows to catch the WebApplicationException, retrieve the actual Response, process the contained entity as exception details (ApiExceptionInfo) and throw an appropriate exception (ApiException).
public <Result> Result get(String path, Class<Result> resultType) {
return perform("GET", path, null, resultType);
}
public <Result> Result post(String path, Object content, Class<Result> resultType) {
return perform("POST", path, content, resultType);
}
private <Result> Result perform(String method, String path, Object content, Class<Result> resultType) {
try {
Entity<Object> entity = null == content ? null : Entity.entity(content, MediaType.APPLICATION_JSON);
return client.target(uri).path(path).request(MediaType.APPLICATION_JSON).method(method, entity, resultType);
} catch (WebApplicationException webApplicationException) {
Response response = webApplicationException.getResponse();
if (response.getMediaType().equals(MediaType.APPLICATION_JSON_TYPE)) {
throw new ApiException(response.readEntity(ApiExceptionInfo.class), webApplicationException);
} else {
throw webApplicationException;
}
}
}
ApiExceptionInfo is custom data type in my application:
import lombok.Data;
#Data
public class ApiExceptionInfo {
private int code;
private String message;
}
ApiException is custom exception type in my application:
import lombok.Getter;
public class ApiException extends RuntimeException {
#Getter
private final ApiExceptionInfo info;
public ApiException(ApiExceptionInfo info, Exception cause) {
super(info.toString(), cause);
this.info = info;
}
}
[At least with Resteasy] there is one big disadvantage with the solution offered by #Chuck M and based on ClientResponseFilter.
When you use it based on ClientResponseFilter, your BadRequestException, NotAuthorizedException, ... exceptions are wrapped by javax.ws.rs.ProcessingException.
Clients of your proxy must not be forced to catch this javax.ws.rs.ResponseProcessingException exception.
Without filter, we get an original rest exception. If we catch and handle by default, it does not give us much:
catch (WebApplicationException e) {
//does not return response body:
e.toString();
// returns null:
e.getCause();
}
The problem can be solved on another level, when you extract a description from the error. WebApplicationException exception, which is a parent for all rest exceptions, contains javax.ws.rs.core.Response. Just write a helper method, that in case the exception is of WebApplicationException type, it will also check the response body. Here is a code in Scala, but the idea should be clear. The methord returns a clear description of the rest exception:
private def descriptiveWebException2String(t: WebApplicationException): String = {
if (t.getResponse.hasEntity)
s"${t.toString}. Response: ${t.getResponse.readEntity(classOf[String])}"
else t.toString
}
Now we move a responsibility to show exact error, on the client. Just use a shared exception handler to minimize effort for clients.
The following works for me
Response.status(Response.Status.BAD_REQUEST).entity(e.getMessage()).build();