Report bad-request for invalid YAML

Added classes and modified code to report bad-request when a servlet
attempts to read invalid YAML.

Change-Id: Iacddee92a448fb69d5c778a3c3f3f2b5528983f7
Issue-ID: POLICY-2085
Signed-off-by: Jim Hahn <jrh3@att.com>

1 files changed, 55 insertions, 0 deletions

diff --git a/policy-endpoints/src/main/java/org/onap/policy/common/endpoints/http/server/YamlExceptionMapper.java b/policy-endpoints/src/main/java/org/onap/policy/common/endpoints/http/server/YamlExceptionMapper.java
new file mode 100644
index 00000000..ac96cab0
--- /dev/null
+++ b/policy-endpoints/src/main/java/org/onap/policy/common/endpoints/http/server/YamlExceptionMapper.java
@@ -0,0 +1,55 @@
+/*-
+ * ============LICENSE_START=======================================================
+ * Copyright (C) 2019 AT&T Intellectual Property. All rights reserved.
+ * ================================================================================
+ * 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
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.common.endpoints.http.server;
+
+import javax.ws.rs.Produces;
+import javax.ws.rs.core.Response;
+import javax.ws.rs.ext.ExceptionMapper;
+import javax.ws.rs.ext.Provider;
+import lombok.Getter;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.yaml.snakeyaml.error.YAMLException;
+
+/**
+ * Catches JSON exceptions when decoding a REST request and converts them from an HTTP 500
+ * error code to an HTTP 400 error code.
+ */
+@Provider
+@Produces("application/yaml")
+public class YamlExceptionMapper implements ExceptionMapper<YAMLException> {
+    private static Logger logger = LoggerFactory.getLogger(YamlExceptionMapper.class);
+
+    @Override
+    public Response toResponse(YAMLException exception) {
+        logger.warn("invalid YAML request", exception);
+        return Response.status(Response.Status.BAD_REQUEST).entity(new SimpleResponse("Invalid request")).build();
+    }
+
+    @Getter
+    private static class SimpleResponse {
+        private String errorDetails;
+
+        public SimpleResponse(String errorDetails) {
+            this.errorDetails = errorDetails;
+        }
+    }
+}