Java tutorial
/* * * 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.consumer; import java.io.ByteArrayOutputStream; import java.io.IOException; import java.io.InputStream; import java.lang.annotation.Annotation; import java.lang.reflect.Type; import javax.ws.rs.Consumes; import javax.ws.rs.WebApplicationException; import javax.ws.rs.core.MediaType; import javax.ws.rs.core.MultivaluedMap; import javax.ws.rs.ext.MessageBodyReader; import javax.ws.rs.ext.Provider; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.apache.hadoop.classification.InterfaceAudience; import org.apache.hadoop.hbase.rest.Constants; import org.apache.hadoop.hbase.rest.ProtobufMessageHandler; /** * Adapter for hooking up Jersey content processing dispatch to * ProtobufMessageHandler interface capable handlers for decoding protobuf input. */ @Provider @Consumes({ Constants.MIMETYPE_PROTOBUF, Constants.MIMETYPE_PROTOBUF_IETF }) @InterfaceAudience.Private public class ProtobufMessageBodyConsumer implements MessageBodyReader<ProtobufMessageHandler> { private static final Log LOG = LogFactory.getLog(ProtobufMessageBodyConsumer.class); @Override public boolean isReadable(Class<?> type, Type genericType, Annotation[] annotations, MediaType mediaType) { return ProtobufMessageHandler.class.isAssignableFrom(type); } @Override public ProtobufMessageHandler readFrom(Class<ProtobufMessageHandler> type, Type genericType, Annotation[] annotations, MediaType mediaType, MultivaluedMap<String, String> httpHeaders, InputStream inputStream) throws IOException, WebApplicationException { ProtobufMessageHandler obj = null; try { obj = type.newInstance(); ByteArrayOutputStream baos = new ByteArrayOutputStream(); byte[] buffer = new byte[4096]; int read; do { read = inputStream.read(buffer, 0, buffer.length); if (read > 0) { baos.write(buffer, 0, read); } } while (read > 0); if (LOG.isDebugEnabled()) { LOG.debug(getClass() + ": read " + baos.size() + " bytes from " + inputStream); } obj = obj.getObjectFromMessage(baos.toByteArray()); } catch (InstantiationException e) { throw new WebApplicationException(e); } catch (IllegalAccessException e) { throw new WebApplicationException(e); } return obj; } }