1 files changed, 95 insertions, 0 deletions
diff --git a/app/src/main/java/org/onap/portalng/history/configuration/Errorhandler.java b/app/src/main/java/org/onap/portalng/history/configuration/Errorhandler.java
new file mode 100644
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+++ b/app/src/main/java/org/onap/portalng/history/configuration/Errorhandler.java
@@ -0,0 +1,95 @@
+/*
+ *
+ * Copyright (c) 2022. Deutsche Telekom AG
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ *
+ */
+
+package org.onap.portalng.history.configuration;
+
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.ObjectMapper;
+
+import org.onap.portalng.history.exception.ProblemException;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.web.reactive.error.ErrorWebExceptionHandler;
+import org.springframework.core.io.buffer.DataBufferFactory;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.server.reactive.ServerHttpResponse;
+import org.springframework.stereotype.Component;
+import org.springframework.web.server.ServerWebExchange;
+import org.zalando.problem.Problem;
+import org.zalando.problem.Status;
+import reactor.core.publisher.Mono;
+
+@Component
+public class Errorhandler implements ErrorWebExceptionHandler {
+
+  @Autowired
+  ObjectMapper objectMapper;
+
+  /**
+   * Override the handle methode to implement custom error handling
+   * Set response status code to BAD REQUEST, set header content-type and fill the body with the Problem object along the API model
+   */
+  @Override
+  public Mono<Void> handle(ServerWebExchange exchange, Throwable ex) {
+    ServerHttpResponse httpResponse = exchange.getResponse();
+    setResponseStatus(httpResponse, ex);
+    httpResponse.getHeaders().add("Content-Type", "application/problem+json");
+    return httpResponse.writeWith(Mono.fromSupplier(() -> {
+      DataBufferFactory bufferFactory = httpResponse.bufferFactory();
+      try {
+         return
+            (httpResponse.getStatusCode() == HttpStatus.INTERNAL_SERVER_ERROR)
+                ? httpResponse.bufferFactory().wrap(objectMapper.writeValueAsBytes(setProblemException(httpResponse, ex.getMessage())))
+                : httpResponse.bufferFactory().wrap(objectMapper.writeValueAsBytes(ex));
+      } catch (JsonProcessingException e) {
+        return bufferFactory.wrap(new byte[0]);
+      }
+    }));
+  }
+
+  /**
+   * Set the response status
+   * @param httpResponse response which status code should be set
+   * @param ex throwable exception to identify the Problem class
+   */
+  private void setResponseStatus(ServerHttpResponse httpResponse, Throwable ex) {
+    if (ex instanceof Problem) {
+      httpResponse.setStatusCode(HttpStatus.BAD_REQUEST);
+    } else {
+      httpResponse.setStatusCode(HttpStatus.INTERNAL_SERVER_ERROR);
+    }
+  }
+
+  /**
+   * Build a problem exception and set the response status code to BAD REQUEST for every response
+   * @param httpResponse response which status code should be set
+   * @param message for the detail of the problem exception
+   * @return problem exception instance
+   */
+  private ProblemException setProblemException(ServerHttpResponse httpResponse, String message){
+    httpResponse.setStatusCode(HttpStatus.BAD_REQUEST);
+    return ProblemException.builder()
+        .status(Status.INTERNAL_SERVER_ERROR)
+        .title(Status.INTERNAL_SERVER_ERROR.getReasonPhrase())
+        .detail(message)
+        .build();
+
+  }
+}