ONOS-2124 Improved web-exception handling when an anonymous exception, i.e. one without a message, is raised.
Top stack-frame will be used as a message if exception has no message of its own.
Change-Id: I28d68e05a0d805c7320e133d8e17081513cb503c
diff --git a/web/api/src/main/java/org/onosproject/rest/exceptions/AbstractMapper.java b/web/api/src/main/java/org/onosproject/rest/exceptions/AbstractMapper.java
index 6f938f4..f49202d 100644
--- a/web/api/src/main/java/org/onosproject/rest/exceptions/AbstractMapper.java
+++ b/web/api/src/main/java/org/onosproject/rest/exceptions/AbstractMapper.java
@@ -21,6 +21,8 @@
import javax.ws.rs.core.Response;
import javax.ws.rs.ext.ExceptionMapper;
+import static com.google.common.base.Strings.isNullOrEmpty;
+
/**
* Base exception mapper implementation.
*/
@@ -49,9 +51,27 @@
protected Response.ResponseBuilder response(Response.Status status,
Throwable exception) {
ObjectMapper mapper = new ObjectMapper();
+ String message = messageFrom(exception);
ObjectNode result = mapper.createObjectNode()
.put("code", status.getStatusCode())
- .put("message", exception.getMessage());
+ .put("message", message);
return Response.status(status).entity(result.toString());
}
+
+ /**
+ * Produces a response message from the supplied exception. Either it will
+ * use the exception message, if there is one, or it will use the top
+ * stack-frame message.
+ *
+ * @param exception exception from which to produce a message
+ * @return response message
+ */
+ protected String messageFrom(Throwable exception) {
+ if (isNullOrEmpty(exception.getMessage())) {
+ StackTraceElement[] trace = exception.getStackTrace();
+ return trace.length == 0 ? "Unknown error" : trace[0].toString();
+ }
+ return exception.getMessage();
+ }
+
}
diff --git a/web/api/src/test/java/org/onosproject/rest/exceptions/ExceptionMapperTest.java b/web/api/src/test/java/org/onosproject/rest/exceptions/ExceptionMapperTest.java
new file mode 100644
index 0000000..779966a
--- /dev/null
+++ b/web/api/src/test/java/org/onosproject/rest/exceptions/ExceptionMapperTest.java
@@ -0,0 +1,35 @@
+/*
+ * Copyright 2015 Open Networking Laboratory
+ *
+ * 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.onosproject.rest.exceptions;
+
+import org.junit.Test;
+
+import static org.junit.Assert.*;
+
+/**
+ * Set of tests for the various exception mappers.
+ */
+public class ExceptionMapperTest {
+
+ @Test
+ public void emptyMessage() {
+ RuntimeException exception = new NullPointerException();
+ ServerErrorMapper mapper = new ServerErrorMapper();
+ Object response = mapper.toResponse(exception).getEntity();
+ assertTrue("incorrect response",
+ response.toString().contains("ExceptionMapperTest.emptyMessage("));
+ }
+}
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