org.hydracache.client.partition.Messager.java Source code

Introduction

Here is the source code for org.hydracache.client.partition.Messager.java

Source

/*
 * Copyright 2010 the original author or authors.
 *
 * 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.hydracache.client.partition;

import org.apache.commons.httpclient.HttpStatus;
import org.apache.log4j.Logger;
import org.hydracache.client.transport.ConflictStatusHandler;
import org.hydracache.client.transport.DefaultResponseMessageHandler;
import org.hydracache.client.transport.RequestMessage;
import org.hydracache.client.transport.ResponseMessage;
import org.hydracache.client.transport.Transport;
import org.hydracache.data.partitioning.SubstancePartition;
import org.hydracache.server.Identity;

public class Messager {
    private static Logger log = Logger.getLogger(Messager.class);

    private Transport transport;

    public Messager(Transport transport) {
        this.transport = transport;

        registerDefaultHandlers();
    }

    private void registerDefaultHandlers() {
        transport.registerHandler(HttpStatus.SC_CONFLICT, new ConflictStatusHandler());
        transport.registerHandler(HttpStatus.SC_OK, new DefaultResponseMessageHandler());
        transport.registerHandler(HttpStatus.SC_CREATED, new DefaultResponseMessageHandler());
    }

    public ResponseMessage sendMessage(Identity target, SubstancePartition nodePartition,
            RequestMessage requestMessage) throws Exception {
        boolean retry = true;
        Identity currentTarget = target;

        try {
            ResponseMessage responseMsg = send(nodePartition, requestMessage, currentTarget);
            return responseMsg;
        } catch (Exception ex) {
            if (retry) {
                currentTarget = nodePartition.next(target);
                ResponseMessage responseMsg = send(nodePartition, requestMessage, currentTarget);
                return responseMsg;
            } else {
                throw ex;
            }
        }
    }

    private ResponseMessage send(SubstancePartition nodePartition, RequestMessage requestMessage,
            Identity currentTarget) throws Exception {
        try {
            transport.establishConnection(currentTarget.getAddress().getHostName(), currentTarget.getPort());

            return transport.sendRequest(requestMessage);
        } catch (Exception ex) {
            log.warn("Failed to send message to node[" + currentTarget + "]");
            deactivateNode(nodePartition, currentTarget);
            throw ex;
        } finally {
            transport.cleanUpConnection();
        }
    }

    private void deactivateNode(SubstancePartition nodePartition, Identity identity) {
        log.info("Removing inaccessible node[" + identity + "]");
        nodePartition.remove(identity);
    }

}