Added an WebExceptionHandler to return JSON errors instead of HTML (#…

…1178)

app/server/appsmith-server/src/main/java/com/appsmith/server/exceptions/AppSmithErrorWebExceptionHandler.java

@@ -0,0 +1,56 @@
+package com.appsmith.server.exceptions;
+
+import com.appsmith.server.dtos.ResponseDTO;
+import org.springframework.beans.factory.ObjectProvider;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.autoconfigure.web.ResourceProperties;
+import org.springframework.boot.autoconfigure.web.ServerProperties;
+import org.springframework.boot.autoconfigure.web.reactive.error.DefaultErrorWebExceptionHandler;
+import org.springframework.boot.web.reactive.error.ErrorAttributes;
+import org.springframework.context.ApplicationContext;
+import org.springframework.core.annotation.Order;
+import org.springframework.http.MediaType;
+import org.springframework.http.codec.ServerCodecConfigurer;
+import org.springframework.stereotype.Component;
+import org.springframework.web.reactive.function.BodyInserters;
+import org.springframework.web.reactive.function.server.RouterFunction;
+import org.springframework.web.reactive.function.server.ServerRequest;
+import org.springframework.web.reactive.function.server.ServerResponse;
+import org.springframework.web.reactive.result.view.ViewResolver;
+import reactor.core.publisher.Mono;
+
+import java.util.Map;
+import java.util.stream.Collectors;
+
+import static org.springframework.web.reactive.function.server.RequestPredicates.all;
+import static org.springframework.web.reactive.function.server.RouterFunctions.route;
+
+@Component
+@Order(-2)
+public class AppSmithErrorWebExceptionHandler extends DefaultErrorWebExceptionHandler {
+ @Autowired
+ public AppSmithErrorWebExceptionHandler(ErrorAttributes errorAttributes, ResourceProperties resourceProperties,
+ ServerProperties serverProperties, ApplicationContext applicationContext,
+ ObjectProvider<ViewResolver> viewResolvers,
+ ServerCodecConfigurer serverCodecConfigurer) {
+ super(errorAttributes, resourceProperties, serverProperties.getError(), applicationContext);
+ this.setViewResolvers(viewResolvers.orderedStream().collect(Collectors.toList()));
+ this.setMessageWriters(serverCodecConfigurer.getWriters());
+ this.setMessageReaders(serverCodecConfigurer.getReaders());
+ }
+
+ @Override
+ protected RouterFunction<ServerResponse> getRoutingFunction(ErrorAttributes errorAttributes) {
+ return route(all(), this::render);
+ }
+
+ private Mono<ServerResponse> render(ServerRequest request) {
+ Map<String, Object> error = getErrorAttributes(request, false);
+ int errorCode = getHttpStatus(error);
+
+ return ServerResponse.status(errorCode).
+ contentType(MediaType.APPLICATION_JSON).
+ body(BodyInserters.
+ fromValue(new ResponseDTO<>(errorCode, new ErrorDTO(errorCode, String.valueOf(error.get("error"))))));
+ }
+}