Added ReaderExceptionMapper: reply to the user with a pre-determined …

…message format if, for example, a JSON entity cannot be parsed

api/metrics-api-jaxrs/src/main/java/org/hawkular/metrics/api/jaxrs/ReaderExceptionMapper.java

@@ -0,0 +1,46 @@
+/*
+ * Copyright 2014-2015 Red Hat, Inc. and/or its affiliates
+ * and other contributors as indicated by the @author tags.
+ *
+ * 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.
+ */
+package org.hawkular.metrics.api.jaxrs;
+
+import javax.ws.rs.core.MediaType;
+import javax.ws.rs.core.Response;
+import javax.ws.rs.ext.ExceptionMapper;
+import javax.ws.rs.ext.Provider;
+
+import org.jboss.resteasy.spi.ReaderException;
+
+import com.google.common.base.Throwables;
+
+/**
+ * Exception mapper for any exception thrown by a body reader chain.
+ * <p>
+ * This mapper let us reply to the user with a pre-determined message format if, for example, a JSON entity cannot be
+ * parsed.
+ *
+ * @author Thomas Segismont
+ */
+@Provider
+public class ReaderExceptionMapper implements ExceptionMapper<ReaderException> {
+
+    @Override
+    public Response toResponse(ReaderException exception) {
+        return Response.status(Response.Status.BAD_REQUEST)
+                       .entity(new ApiError(Throwables.getRootCause(exception).getMessage()))
+                       .type(MediaType.APPLICATION_JSON)
+                       .build();
+    }
+}

rest-tests/src/test/groovy/org/hawkular/metrics/rest/TenantITest.groovy

@@ -21,6 +21,9 @@ import static org.junit.Assert.assertTrue
 
 import org.junit.Test
 
+/**
+ * @author Thomas Segismont
+ */
 class TenantITest extends RESTTest {
 
   @Test
@@ -67,4 +70,12 @@ class TenantITest extends RESTTest {
     }
   }
 
+  @Test
+  void invalidPayloadTest() {
+    badPost(path: 'tenants', body: [] /* Empty body */) { exception ->
+      assertEquals(400, exception.response.status)
+      assertTrue(exception.response.data.containsKey("errorMsg"))
+    }
+  }
+
 }