Initial sketch of codecs and REST API approach.
FIxed typos and defects.
ONOS-81

Change-Id: I789444a181abea509c354966545c927e305710d1
diff --git a/web/api/src/main/java/org/onlab/onos/rest/JsonBodyWriter.java b/web/api/src/main/java/org/onlab/onos/rest/JsonBodyWriter.java
new file mode 100644
index 0000000..d34e30e
--- /dev/null
+++ b/web/api/src/main/java/org/onlab/onos/rest/JsonBodyWriter.java
@@ -0,0 +1,58 @@
+/*
+ * Copyright 2014 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.onlab.onos.rest;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.node.ObjectNode;
+
+import javax.ws.rs.Produces;
+import javax.ws.rs.core.MediaType;
+import javax.ws.rs.core.MultivaluedMap;
+import javax.ws.rs.ext.MessageBodyWriter;
+import java.io.IOException;
+import java.io.OutputStream;
+import java.lang.annotation.Annotation;
+import java.lang.reflect.Type;
+
+/**
+ * JAX-RS Response message body writer.
+ */
+@Produces("application/json")
+public class JsonBodyWriter implements MessageBodyWriter<ObjectNode> {
+
+    private ObjectMapper mapper = new ObjectMapper();
+
+    @Override
+    public boolean isWriteable(Class<?> type, Type genericType,
+                               Annotation[] annotations, MediaType mediaType) {
+        return type == ObjectNode.class;
+    }
+
+    @Override
+    public long getSize(ObjectNode node, Class<?> type, Type genericType,
+                        Annotation[] annotations, MediaType mediaType) {
+        return -1;
+    }
+
+    @Override
+    public void writeTo(ObjectNode node, Class<?> type, Type genericType,
+                        Annotation[] annotations, MediaType mediaType,
+                        MultivaluedMap<String, Object> httpHeaders,
+                        OutputStream entityStream) throws IOException {
+        mapper.writer().writeValue(entityStream, node);
+        entityStream.flush();
+    }
+}