Exception Mapping (#1390)

* Exception Mapping

* Don't even need to create the Writer myself, even better.

* Put "activation" back in. fixes #1388

* Rename filter so it resembles the actual query param

* ...and the code comment

* License headers

web-api/src/main/java/com/graphhopper/MultiException.java

@@ -0,0 +1,40 @@
+/*
+ *  Licensed to GraphHopper GmbH under one or more contributor
+ *  license agreements. See the NOTICE file distributed with this work for
+ *  additional information regarding copyright ownership.
+ *
+ *  GraphHopper GmbH licenses this file to you 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 com.graphhopper;
+
+import java.util.Collections;
+import java.util.List;
+
+public class MultiException extends RuntimeException {
+
+    private final List<Throwable> errors;
+
+    public MultiException(List<Throwable> errors) {
+        this.errors = errors;
+    }
+
+    public MultiException(Throwable e) {
+        this(Collections.singletonList(e));
+    }
+
+    public List<Throwable> getErrors() {
+        return errors;
+    }
+
+}

web-api/src/main/java/com/graphhopper/jackson/GraphHopperModule.java

@@ -1,6 +1,7 @@
 package com.graphhopper.jackson;
 
 import com.fasterxml.jackson.databind.module.SimpleModule;
+import com.graphhopper.MultiException;
 import com.graphhopper.util.CmdArgs;
 import com.graphhopper.util.InstructionList;
 import com.graphhopper.util.details.PathDetail;
@@ -18,6 +19,7 @@ public GraphHopperModule() {
         addSerializer(PathDetail.class, new PathDetailSerializer());
         addSerializer(InstructionList.class, new InstructionListSerializer());
         addDeserializer(CmdArgs.class, new CmdArgsDeserializer());
+        addSerializer(MultiException.class, new MultiExceptionSerializer());
     }
 
 }

web-api/src/main/java/com/graphhopper/jackson/MultiExceptionSerializer.java

@@ -0,0 +1,59 @@
+/*
+ *  Licensed to GraphHopper GmbH under one or more contributor
+ *  license agreements. See the NOTICE file distributed with this work for
+ *  additional information regarding copyright ownership.
+ *
+ *  GraphHopper GmbH licenses this file to you 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 com.graphhopper.jackson;
+
+import com.fasterxml.jackson.core.JsonGenerator;
+import com.fasterxml.jackson.databind.JsonSerializer;
+import com.fasterxml.jackson.databind.SerializerProvider;
+import com.fasterxml.jackson.databind.node.ArrayNode;
+import com.fasterxml.jackson.databind.node.JsonNodeFactory;
+import com.fasterxml.jackson.databind.node.ObjectNode;
+import com.graphhopper.MultiException;
+import com.graphhopper.util.exceptions.GHException;
+
+import java.io.IOException;
+import java.util.List;
+
+public class MultiExceptionSerializer extends JsonSerializer<MultiException> {
+
+    @Override
+    public void serialize(MultiException e, JsonGenerator jsonGenerator, SerializerProvider serializerProvider) throws IOException {
+        List<Throwable> errors = e.getErrors();
+        ObjectNode json = JsonNodeFactory.instance.objectNode();
+        json.put("message", getMessage(errors.get(0)));
+        ArrayNode errorHintList = json.putArray("hints");
+        for (Throwable t : errors) {
+            ObjectNode error = errorHintList.addObject();
+            error.put("message", getMessage(t));
+            error.put("details", t.getClass().getName());
+            if (t instanceof GHException) {
+                ((GHException) t).getDetails().forEach(error::putPOJO);
+            }
+        }
+        jsonGenerator.writeObject(json);
+    }
+
+    private static String getMessage(Throwable t) {
+        if (t.getMessage() == null)
+            return t.getClass().getSimpleName();
+        else
+            return t.getMessage();
+    }
+
+}

web-bundle/src/main/java/com/graphhopper/http/GraphHopperBundle.java

@@ -183,6 +183,14 @@ public void serializeAsField(Object bean, JsonGenerator gen, SerializerProvider
     public void run(GraphHopperBundleConfiguration configuration, Environment environment) {
         configuration.getGraphHopperConfiguration().merge(CmdArgs.readFromSystemProperties());
 
+        // If the "?type=gpx" parameter is present, sets a corresponding media type header
+        environment.jersey().register(new TypeGPXFilter());
+
+        // Together, these two take care that MultiExceptions thrown from RouteResource
+        // come out as JSON or GPX, depending on the media type
+        environment.jersey().register(new MultiExceptionMapper());
+        environment.jersey().register(new MultiExceptionGPXMessageBodyWriter());
+
         if (configuration.getGraphHopperConfiguration().has("gtfs.file")) {
             // switch to different API implementation when using Pt
             runPtGraphHopper(configuration.getGraphHopperConfiguration(), environment);
@@ -263,7 +271,6 @@ protected void configure() {
         environment.jersey().register(IsochroneResource.class);
         environment.jersey().register(I18NResource.class);
         environment.jersey().register(InfoResource.class);
-
         environment.healthChecks().register("graphhopper", new GraphHopperHealthCheck(graphHopperManaged.getGraphHopper()));
     }
 

web-bundle/src/main/java/com/graphhopper/http/MultiExceptionGPXMessageBodyWriter.java

@@ -0,0 +1,99 @@
+/*
+ *  Licensed to GraphHopper GmbH under one or more contributor
+ *  license agreements. See the NOTICE file distributed with this work for
+ *  additional information regarding copyright ownership.
+ *
+ *  GraphHopper GmbH licenses this file to you 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 com.graphhopper.http;
+
+import com.graphhopper.MultiException;
+import org.w3c.dom.Document;
+import org.w3c.dom.Element;
+
+import javax.ws.rs.Produces;
+import javax.ws.rs.WebApplicationException;
+import javax.ws.rs.core.MediaType;
+import javax.ws.rs.core.MultivaluedMap;
+import javax.ws.rs.ext.MessageBodyWriter;
+import javax.ws.rs.ext.Provider;
+import javax.xml.parsers.DocumentBuilder;
+import javax.xml.parsers.DocumentBuilderFactory;
+import javax.xml.parsers.ParserConfigurationException;
+import javax.xml.transform.Transformer;
+import javax.xml.transform.TransformerException;
+import javax.xml.transform.TransformerFactory;
+import javax.xml.transform.dom.DOMSource;
+import javax.xml.transform.stream.StreamResult;
+import java.io.IOException;
+import java.io.OutputStream;
+import java.lang.annotation.Annotation;
+import java.lang.reflect.Type;
+
+@Provider
+@Produces("application/gpx+xml")
+public class MultiExceptionGPXMessageBodyWriter implements MessageBodyWriter<MultiException> {
+
+    @Override
+    public boolean isWriteable(Class<?> type, Type genericType, Annotation[] annotations, MediaType mediaType) {
+        return true;
+    }
+
+    @Override
+    public long getSize(MultiException e, Class<?> type, Type genericType, Annotation[] annotations, MediaType mediaType) {
+        return -1;
+    }
+
+    @Override
+    public void writeTo(MultiException e, Class<?> type, Type genericType, Annotation[] annotations, MediaType mediaType, MultivaluedMap<String, Object> httpHeaders, OutputStream entityStream) throws IOException, WebApplicationException {
+        if (e.getErrors().isEmpty())
+            throw new RuntimeException("errorsToXML should not be called with an empty list");
+
+        try {
+            DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
+            DocumentBuilder builder = factory.newDocumentBuilder();
+            Document doc = builder.newDocument();
+            Element gpxElement = doc.createElement("gpx");
+            gpxElement.setAttribute("creator", "GraphHopper");
+            gpxElement.setAttribute("version", "1.1");
+            doc.appendChild(gpxElement);
+
+            Element mdElement = doc.createElement("metadata");
+            gpxElement.appendChild(mdElement);
+
+            Element extensionsElement = doc.createElement("extensions");
+            mdElement.appendChild(extensionsElement);
+
+            Element messageElement = doc.createElement("message");
+            extensionsElement.appendChild(messageElement);
+            messageElement.setTextContent(e.getErrors().iterator().next().getMessage());
+
+            Element hintsElement = doc.createElement("hints");
+            extensionsElement.appendChild(hintsElement);
+
+            for (Throwable t : e.getErrors()) {
+                Element error = doc.createElement("error");
+                hintsElement.appendChild(error);
+                error.setAttribute("message", t.getMessage());
+                error.setAttribute("details", t.getClass().getName());
+            }
+            TransformerFactory transformerFactory = TransformerFactory.newInstance();
+            Transformer transformer = transformerFactory.newTransformer();
+            transformer.transform(new DOMSource(doc), new StreamResult(entityStream));
+        } catch (ParserConfigurationException | TransformerException e2) {
+            throw new RuntimeException(e2);
+        }
+
+    }
+}

web-bundle/src/main/java/com/graphhopper/http/MultiExceptionMapper.java

@@ -0,0 +1,33 @@
+/*
+ *  Licensed to GraphHopper GmbH under one or more contributor
+ *  license agreements. See the NOTICE file distributed with this work for
+ *  additional information regarding copyright ownership.
+ *
+ *  GraphHopper GmbH licenses this file to you 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 com.graphhopper.http;
+
+import com.graphhopper.MultiException;
+
+import javax.ws.rs.core.Response;
+import javax.ws.rs.ext.ExceptionMapper;
+import javax.ws.rs.ext.Provider;
+
+@Provider
+public class MultiExceptionMapper implements ExceptionMapper<MultiException> {
+    @Override
+    public Response toResponse(MultiException exception) {
+        return Response.status(400).entity(exception).build();
+    }
+}

web-bundle/src/main/java/com/graphhopper/http/TypeGPXFilter.java

@@ -0,0 +1,40 @@
+/*
+ *  Licensed to GraphHopper GmbH under one or more contributor
+ *  license agreements. See the NOTICE file distributed with this work for
+ *  additional information regarding copyright ownership.
+ *
+ *  GraphHopper GmbH licenses this file to you 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 com.graphhopper.http;
+
+import javax.annotation.Priority;
+import javax.ws.rs.Priorities;
+import javax.ws.rs.container.ContainerRequestContext;
+import javax.ws.rs.container.ContainerRequestFilter;
+import javax.ws.rs.container.PreMatching;
+import javax.ws.rs.core.HttpHeaders;
+
+@PreMatching
+@Priority(Priorities.HEADER_DECORATOR)
+public class TypeGPXFilter implements ContainerRequestFilter {
+
+    @Override
+    public void filter(ContainerRequestContext rc) {
+        String maybeType = rc.getUriInfo().getQueryParameters().getFirst("type");
+        if (maybeType != null && maybeType.equals("gpx")) {
+            rc.getHeaders().putSingle(HttpHeaders.ACCEPT, "application/gpx+xml");
+        }
+    }
+
+}