/*
    *
    * 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.hadoop.hbase.rest.provider.producer;
  
  import java.io.IOException;
  import java.io.OutputStream;
  import java.lang.annotation.Annotation;
  import java.lang.reflect.Type;
  
  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 org.apache.hadoop.hbase.classification.InterfaceAudience;
  import org.apache.hadoop.hbase.rest.Constants;
  
  /**
   * An adapter between Jersey and Object.toString(). Hooks up plain text output
   * to the Jersey content handling framework. 
   * Jersey will first call getSize() to learn the number of bytes that will be
   * sent, then writeTo to perform the actual I/O.
   */
  @Provider
  @Produces(Constants.MIMETYPE_TEXT)
  @InterfaceAudience.Private
  public class PlainTextMessageBodyProducer 
    implements MessageBodyWriter<Object> {
  
    private ThreadLocal<byte[]> buffer = new ThreadLocal<byte[]>();
  
    @Override
    public boolean isWriteable(Class<?> arg0, Type arg1, Annotation[] arg2,
        MediaType arg3) {
      return true;
    }
  
    @Override
    public long getSize(Object object, Class<?> type, Type genericType,
        Annotation[] annotations, MediaType mediaType) {
      byte[] bytes = object.toString().getBytes(); 
      buffer.set(bytes);
      return bytes.length;
    }
  
    @Override
    public void writeTo(Object object, Class<?> type, Type genericType,
        Annotation[] annotations, MediaType mediaType,
        MultivaluedMap<String, Object> httpHeaders, OutputStream outStream)
        throws IOException, WebApplicationException {
      byte[] bytes = buffer.get();
      outStream.write(bytes);
      buffer.remove();
    }	
  }