[OLINGO-349] ODataError serialization. Move to commons pending

lib/server-api/src/main/java/org/apache/olingo/server/api/serializer/ODataError.java

@@ -0,0 +1,88 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF 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 org.apache.olingo.server.api.serializer;
+
+//TODO: Where to put this class
+public class ODataError {
+
+  String code;
+  String message;
+  String target;
+
+  /**
+   * The value for the code name/value pair is a language-independent string. Its value is a service-defined error code.
+   * This code serves as a sub-status for the HTTP error code specified in the response. MAY be null.
+   * @return the error code as a string
+   */
+  public String getCode() {
+    return code;
+  }
+
+  /**
+   * The value for the code name/value pair is a language-independent string. Its value is a service-defined error code.
+   * This code serves as a sub-status for the HTTP error code specified in the response. MAY be null.
+   * @param code
+   * @return this for method chaining
+   */
+  public ODataError setCode(String code) {
+    this.code = code;
+    return this;
+  }
+
+  /**
+   * The value for the message name/value pair MUST be a human-readable, language-dependent representation of the error.
+   * MUST not be null
+   * @return the message string
+   */
+  public String getMessage() {
+    return message;
+  }
+
+  /**
+   * The value for the message name/value pair MUST be a human-readable, language-dependent representation of the error.
+   * MUST not be null
+   * @param message
+   * @return this for method chaining
+   */
+  public ODataError setMessage(String message) {
+    this.message = message;
+    return this;
+  }
+
+  /**
+   * The value for the target name/value pair is the target of the particular error (for example, the name of the
+   * property in error). MAY be null.
+   * @return the target string
+   */
+  public String getTarget() {
+    return target;
+  }
+
+  /**
+   * The value for the target name/value pair is the target of the particular error (for example, the name of the
+   * property in error). MAY be null.
+   * @param target
+   * @return this for method chaining
+   */
+  public ODataError setTarget(String target) {
+    this.target = target;
+    return this;
+  }
+
+}

lib/server-api/src/main/java/org/apache/olingo/server/api/serializer/ODataSerializer.java

@@ -19,6 +19,7 @@
 package org.apache.olingo.server.api.serializer;
 
 import java.io.InputStream;
+import java.util.List;
 
 import org.apache.olingo.commons.api.data.ContextURL;
 import org.apache.olingo.commons.api.data.Entity;
@@ -38,4 +39,12 @@ public interface ODataSerializer {
   InputStream entity(EdmEntityType edmEntityType, Entity entity, ContextURL contextURL);
 
   InputStream entitySet(EdmEntitySet edmEntitySet, EntitySet entitySet, ContextURL contextURL);
+
+  /**
+   * Writes an ODataError into an InputStream
+   * @param error the main error
+   * @param details a list of details. MAY be null or empty.
+   * @return inputStream containing the OData formatted error
+   */
+  InputStream error(ODataError error, List<ODataError> details);
 }

lib/server-core/pom.xml

@@ -69,6 +69,11 @@
       <groupId>org.slf4j</groupId>
       <artifactId>slf4j-simple</artifactId>
     </dependency>
+    <dependency>
+      <groupId>commons-io</groupId>
+      <artifactId>commons-io</artifactId>
+      <scope>test</scope>
+    </dependency>
   </dependencies>
 
   <build>

lib/server-core/src/main/java/org/apache/olingo/server/core/serializer/ODataXmlSerializerImpl.java

@@ -19,6 +19,7 @@
 package org.apache.olingo.server.core.serializer;
 
 import java.io.InputStream;
+import java.util.List;
 
 import javax.xml.stream.XMLOutputFactory;
 import javax.xml.stream.XMLStreamException;
@@ -31,6 +32,7 @@ import org.apache.olingo.commons.api.data.EntitySet;
 import org.apache.olingo.commons.api.edm.Edm;
 import org.apache.olingo.commons.api.edm.EdmEntitySet;
 import org.apache.olingo.commons.api.edm.EdmEntityType;
+import org.apache.olingo.server.api.serializer.ODataError;
 import org.apache.olingo.server.api.serializer.ODataSerializer;
 import org.apache.olingo.server.core.serializer.utils.CircleStreamBuffer;
 import org.apache.olingo.server.core.serializer.xml.MetadataDocumentXmlSerializer;
@@ -86,4 +88,9 @@ public class ODataXmlSerializerImpl implements ODataSerializer {
     throw new ODataRuntimeException("Entityset serialization not implemented for XML format");
   }
 
+  @Override
+  public InputStream error(ODataError error, List<ODataError> details) {
+    throw new ODataRuntimeException("error serialization not implemented for XML format");
+  }
+
 }

lib/server-core/src/main/java/org/apache/olingo/server/core/serializer/json/ODataErrorSerializer.java

@@ -0,0 +1,78 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF 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 org.apache.olingo.server.core.serializer.json;
+
+import java.io.IOException;
+import java.util.List;
+
+import org.apache.olingo.commons.api.ODataRuntimeException;
+import org.apache.olingo.server.api.serializer.ODataError;
+
+import com.fasterxml.jackson.core.JsonGenerationException;
+import com.fasterxml.jackson.core.JsonGenerator;
+
+public class ODataErrorSerializer {
+
+  private static final String ERROR = "error";
+  private static final String CODE = "code";
+  private static final String MESSAGE = "message";
+  private static final String TARGET = "target";
+  private static final String DETAILS = "details";
+
+  public void writeErrorDocument(JsonGenerator json, ODataError error, List<ODataError> details) throws IOException {
+    if (error == null) {
+      throw new ODataRuntimeException("ODataError object MUST NOT be null!");
+    }
+    json.writeStartObject();
+    json.writeFieldName(ERROR);
+
+    json.writeStartObject();
+    writeODataError(json, error);
+    
+    if(details != null){
+      json.writeArrayFieldStart(DETAILS);
+      for(ODataError detailedError : details){
+        json.writeStartObject();
+        writeODataError(json, detailedError);
+        json.writeEndObject();
+      }
+      json.writeEndArray();
+    }
+
+    json.writeEndObject();
+    json.writeEndObject();
+  }
+
+  private void writeODataError(JsonGenerator json, ODataError error) throws IOException, JsonGenerationException {
+    if (error.getCode() == null) {
+      json.writeNullField(CODE);
+    } else {
+      json.writeStringField(CODE, error.getCode());
+    }
+    if (error.getMessage() == null) {
+      json.writeNullField(MESSAGE);
+    } else {
+      json.writeStringField(MESSAGE, error.getMessage());
+    }
+
+    if (error.getTarget() != null) {
+      json.writeStringField(TARGET, error.getTarget());
+    }
+  }
+}

lib/server-core/src/main/java/org/apache/olingo/server/core/serializer/json/ODataJsonSerializer.java

@@ -26,6 +26,7 @@ import org.apache.olingo.commons.api.ODataRuntimeException;
 import org.apache.olingo.commons.api.data.*;
 import org.apache.olingo.commons.api.edm.*;
 import org.apache.olingo.commons.core.edm.primitivetype.EdmPrimitiveTypeFactory;
+import org.apache.olingo.server.api.serializer.ODataError;
 import org.apache.olingo.server.api.serializer.ODataSerializer;
 import org.apache.olingo.server.core.serializer.utils.CircleStreamBuffer;
 import org.slf4j.Logger;
@@ -172,7 +173,7 @@ public class ODataJsonSerializer implements ODataSerializer {
         writePrimitive(edmProperty, property, json);
       } else if (property.isLinkedComplex()) {
         writeComplexValue(edmProperty, property.asLinkedComplex().getValue(), json);
-      } else if(property.isComplex()) {
+      } else if (property.isComplex()) {
         writeComplexValue(edmProperty, property.asComplex(), json);
       } else {
         throw new ODataRuntimeException("Property type not yet supported!");
@@ -180,6 +181,7 @@ public class ODataJsonSerializer implements ODataSerializer {
     }
   }
 
+
   private void writeCollection(EdmProperty edmProperty, Property property, JsonGenerator json)
           throws IOException, EdmPrimitiveTypeException {
     json.writeStartArray();
@@ -243,7 +245,7 @@ public class ODataJsonSerializer implements ODataSerializer {
   }
 
   private void writeComplexValue(final EdmProperty edmProperty, final List<Property> properties,
-                                       JsonGenerator json) throws IOException, EdmPrimitiveTypeException {
+      JsonGenerator json) throws IOException, EdmPrimitiveTypeException {
     final EdmComplexType type = (EdmComplexType) edmProperty.getType();
     json.writeStartObject();
     for (final String propertyName : type.getPropertyNames()) {
@@ -261,4 +263,18 @@ public class ODataJsonSerializer implements ODataSerializer {
     }
     return null;
   }
+
+  @Override
+  public InputStream error(ODataError error, List<ODataError> details) {
+    CircleStreamBuffer buffer = new CircleStreamBuffer();
+    try {
+      JsonGenerator json = new JsonFactory().createGenerator(buffer.getOutputStream());
+      ODataErrorSerializer ser = new ODataErrorSerializer();
+      ser.writeErrorDocument(json, error, details);
+      json.close();
+    } catch (final IOException e) {
+      throw new ODataRuntimeException(e);
+    }
+    return buffer.getInputStream();
+  }
 }

lib/server-core/src/test/java/org/apache/olingo/server/core/serializer/json/ODataErrorSerializerTest.java

@@ -0,0 +1,134 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF 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 org.apache.olingo.server.core.serializer.json;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+
+import java.io.InputStream;
+import java.util.ArrayList;
+import java.util.List;
+
+import org.apache.commons.io.IOUtils;
+import org.apache.olingo.commons.api.ODataRuntimeException;
+import org.apache.olingo.commons.api.format.ODataFormat;
+import org.apache.olingo.server.api.OData;
+import org.apache.olingo.server.api.serializer.ODataError;
+import org.apache.olingo.server.api.serializer.ODataSerializer;
+import org.junit.Before;
+import org.junit.Test;
+
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.node.JsonNodeType;
+
+public class ODataErrorSerializerTest {
+
+  ODataSerializer ser;
+
+  @Before
+  public void before() {
+    ser = OData.newInstance().createSerializer(ODataFormat.JSON);
+  }
+
+  @Test
+  public void basicODataErrorNoCode() throws Exception {
+    ODataError error = new ODataError();
+    error.setMessage("ErrorMessage");
+    InputStream stream = ser.error(error, null);
+    String jsonString = IOUtils.toString(stream);
+    assertEquals("{\"error\":{\"code\":null,\"message\":\"ErrorMessage\"}}", jsonString);
+  }
+
+  @Test
+  public void basicODataErrorWithCode() throws Exception {
+    ODataError error = new ODataError();
+    error.setCode("Code").setMessage("ErrorMessage");
+    InputStream stream = ser.error(error, null);
+    String jsonString = IOUtils.toString(stream);
+    assertEquals("{\"error\":{\"code\":\"Code\",\"message\":\"ErrorMessage\"}}", jsonString);
+  }
+
+  @Test
+  public void basicODataErrorWithCodeAndTarget() throws Exception {
+    ODataError error = new ODataError();
+    error.setCode("Code").setMessage("ErrorMessage").setTarget("Target");
+    InputStream stream = ser.error(error, null);
+    String jsonString = IOUtils.toString(stream);
+    assertEquals("{\"error\":{\"code\":\"Code\",\"message\":\"ErrorMessage\",\"target\":\"Target\"}}", jsonString);
+  }
+
+  @Test(expected = ODataRuntimeException.class)
+  public void nullErrorResultsInException() throws Exception {
+    ser.error(null, null);
+  }
+
+  @Test
+  public void emptyDetailsList() throws Exception {
+    ODataError error = new ODataError();
+    error.setMessage("ErrorMessage");
+    InputStream stream = ser.error(error, new ArrayList<ODataError>());
+    String jsonString = IOUtils.toString(stream);
+    assertEquals("{\"error\":{\"code\":null,\"message\":\"ErrorMessage\",\"details\":[]}}", jsonString);
+  }
+
+  @Test
+  public void nothingSetAtODataErrorObject() throws Exception {
+    ODataError error = new ODataError();
+    InputStream stream = ser.error(error, null);
+    String jsonString = IOUtils.toString(stream);
+    assertEquals("{\"error\":{\"code\":null,\"message\":null}}", jsonString);
+  }
+
+  @Test
+  public void singleDetailNothingSet() throws Exception {
+    List<ODataError> details = new ArrayList<ODataError>();
+    details.add(new ODataError());
+    ODataError error = new ODataError();
+    InputStream stream = ser.error(error, details);
+    String jsonString = IOUtils.toString(stream);
+    assertEquals("{\"error\":{\"code\":null,\"message\":null,\"details\":[{\"code\":null,\"message\":null}]}}",
+        jsonString);
+  }
+
+  @Test
+  public void verifiedWithJacksonParser() throws Exception {
+    List<ODataError> details = new ArrayList<ODataError>();
+    details.add(new ODataError().setCode("detailCode").setMessage("detailMessage").setTarget("detailTarget"));
+    ODataError error = new ODataError().setCode("Code").setMessage("Message").setTarget("Target");
+    InputStream stream = ser.error(error, details);
+    JsonNode tree = new ObjectMapper().readTree(stream);
+    assertNotNull(tree);
+    tree = tree.get("error");
+    assertNotNull(tree);
+    assertEquals("Code", tree.get("code").textValue());
+    assertEquals("Message", tree.get("message").textValue());
+    assertEquals("Target", tree.get("target").textValue());
+
+    tree = tree.get("details");
+    assertNotNull(tree);
+    assertEquals(JsonNodeType.ARRAY, tree.getNodeType());
+
+    tree = tree.get(0);
+    assertNotNull(tree);
+    assertEquals("detailCode", tree.get("code").textValue());
+    assertEquals("detailMessage", tree.get("message").textValue());
+    assertEquals("detailTarget", tree.get("target").textValue());
+  }
+}