Skip to content

Prevent loadbalancer filter to wrap exception into RuntimeException #4020

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
ryanjbaxter merged 3 commits into from
Apr 15, 2026
+49 −1
Merged

Prevent loadbalancer filter to wrap exception into RuntimeException #4020

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
3 commits
Select commit Hold shift + click to select a range
8add9df
Prevent loadbalancer filter to wrap exception into RuntimeException
ComputerDaddyGuy Dec 13, 2025
bddf890
Keep lambda instead of anonymous class
ComputerDaddyGuy Apr 15, 2026
5c9a5c3
Fix auto format
ComputerDaddyGuy Apr 15, 2026
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
5 changes: 4 additions & 1 deletion ...java/org/springframework/cloud/gateway/server/mvc/filter/LoadBalancerFilterFunctions.java
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -50,6 +50,9 @@

import static org.springframework.cloud.gateway.server.mvc.common.MvcUtils.getApplicationContext;

/**
* @author Samuel Schnegg
*/
public abstract class LoadBalancerFilterFunctions {

private static final Log log = LogFactory.getLog(LoadBalancerFilterFunctions.class);
Expand Down Expand Up @@ -122,7 +125,7 @@ public static HandlerFilterFunction<ServerResponse, ServerResponse> lb(String se
supportedLifecycleProcessors.forEach(lifecycle -> lifecycle.onComplete(
new CompletionContext<>(CompletionContext.Status.FAILED, e, lbRequest, defaultResponse)));

throw new RuntimeException(e);
throw e;
}
};
}
Expand Down
45 changes: 45 additions & 0 deletions ...src/test/java/org/springframework/cloud/gateway/server/mvc/ServerMvcIntegrationTests.java
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -84,6 +84,7 @@
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.servlet.function.HandlerFilterFunction;
import org.springframework.web.servlet.function.HandlerFunction;
import org.springframework.web.servlet.function.RouterFunction;
import org.springframework.web.servlet.function.ServerRequest;
Expand Down Expand Up @@ -369,6 +370,19 @@ public void loadbalancerWorks() {
});
}

@Test
public void loadbalancerDoesNotWrapException() {
restClient.get()
.uri("/anything/loadbalancer-does-not-wrap-exception")
.exchange()
.expectStatus()
.is5xxServerError()
.expectHeader()
.valueEquals("X-Exception-ClassName", "IOException")
.expectHeader()
.valueEquals("X-Exception-Message", "A custom exception");
}

@Test
public void hostPredicateWorks() {
String host = "www1.myjavadslhost.com";
Expand Down Expand Up @@ -1188,6 +1202,37 @@ public RouterFunction<ServerResponse> gatewayRouterFunctionsLoadBalancer() {
// @formatter:on
}

@Bean
public RouterFunction<ServerResponse> gatewayRouterFunctionsLoadBalancerDoesNotWrapException() {
HandlerFilterFunction<ServerResponse, ServerResponse> addExceptionDetailsInResponseHeadersFilter = (request,
next) -> {
try {
return next.handle(request);
}
catch (Exception e) {
return ServerResponse.status(HttpStatus.INTERNAL_SERVER_ERROR)
.header("X-Exception-ClassName", e.getClass().getSimpleName())
.header("X-Exception-Message", e.getMessage())
.build();
}

};

var throwingExceptionFilter = (HandlerFilterFunction<ServerResponse, ServerResponse>) (request, next) -> {
throw new IOException("A custom exception");
};

// @formatter:off
return route()
.GET("/anything/loadbalancer-does-not-wrap-exception", http())
.filter(addExceptionDetailsInResponseHeadersFilter)
.filter(lb("httpbin"))
.filter(throwingExceptionFilter)
.withAttribute(MvcUtils.GATEWAY_ROUTE_ID_ATTR, "testloadbalancerForException")
.build();
// @formatter:on
}

@Bean
public RouterFunction<ServerResponse> gatewayRouterFunctionsHost() {
// @formatter:off
Expand Down