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.axis2.clustering.tribes; import org.apache.axis2.clustering.ClusteringCommand; import org.apache.axis2.clustering.ClusteringFault; import org.apache.axis2.clustering.MessageSender; import org.apache.catalina.tribes.ByteMessage; import org.apache.catalina.tribes.Channel; import org.apache.catalina.tribes.ChannelException; import org.apache.catalina.tribes.Member; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import java.io.ByteArrayOutputStream; import java.io.IOException; import java.io.NotSerializableException; import java.io.ObjectOutputStream; public class ChannelSender implements MessageSender { private static Log log = LogFactory.getLog(ChannelSender.class); private Channel channel; private boolean synchronizeAllMembers; private MembershipManager membershipManager; public ChannelSender(Channel channel, MembershipManager membershipManager, boolean synchronizeAllMembers) { this.channel = channel; this.membershipManager = membershipManager; this.synchronizeAllMembers = synchronizeAllMembers; } public synchronized void sendToGroup(ClusteringCommand msg, MembershipManager membershipManager, int additionalOptions) throws ClusteringFault { if (channel == null) { return; } Member[] members = membershipManager.getMembers(); // Keep retrying, since at the point of trying to send the msg, a member may leave the group // causing a view change. All nodes in a view should get the msg if (members.length > 0) { try { if (synchronizeAllMembers) { channel.send(members, toByteMessage(msg), Channel.SEND_OPTIONS_USE_ACK | Channel.SEND_OPTIONS_SYNCHRONIZED_ACK | Channel.SEND_OPTIONS_BYTE_MESSAGE | TribesConstants.MSG_ORDER_OPTION | TribesConstants.AT_MOST_ONCE_OPTION | additionalOptions); } else { channel.send(members, toByteMessage(msg), Channel.SEND_OPTIONS_ASYNCHRONOUS | TribesConstants.MSG_ORDER_OPTION | Channel.SEND_OPTIONS_BYTE_MESSAGE | TribesConstants.AT_MOST_ONCE_OPTION | additionalOptions); } if (log.isDebugEnabled()) { log.debug("Sent " + msg + " to group"); } } catch (NotSerializableException e) { String message = "Could not send command message " + msg + " to group since it is not serializable."; log.error(message, e); throw new ClusteringFault(message, e); } catch (ChannelException e) { log.error("Could not send message to some members", e); ChannelException.FaultyMember[] faultyMembers = e.getFaultyMembers(); for (ChannelException.FaultyMember faultyMember : faultyMembers) { Member member = faultyMember.getMember(); log.error("Member " + TribesUtil.getName(member) + " is faulty", faultyMember.getCause()); } } catch (Exception e) { String message = "Error sending command message : " + msg + ". Reason " + e.getMessage(); log.warn(message, e); } } } public void sendToGroup(ClusteringCommand msg) throws ClusteringFault { sendToGroup(msg, this.membershipManager, 0); } private ByteMessage toByteMessage(ClusteringCommand msg) throws IOException { ByteArrayOutputStream bos = new ByteArrayOutputStream(); ObjectOutputStream out = new ObjectOutputStream(bos); out.writeObject(msg); out.flush(); out.close(); return new ByteMessage(bos.toByteArray()); } public void sendToSelf(ClusteringCommand msg) throws ClusteringFault { if (channel == null) { return; } try { channel.send(new Member[] { channel.getLocalMember(true) }, toByteMessage(msg), Channel.SEND_OPTIONS_USE_ACK | Channel.SEND_OPTIONS_BYTE_MESSAGE); if (log.isDebugEnabled()) { log.debug("Sent " + msg + " to self"); } } catch (Exception e) { throw new ClusteringFault(e); } } public void sendToMember(ClusteringCommand cmd, Member member) throws ClusteringFault { try { if (member.isReady()) { channel.send(new Member[] { member }, toByteMessage(cmd), Channel.SEND_OPTIONS_USE_ACK | Channel.SEND_OPTIONS_SYNCHRONIZED_ACK | Channel.SEND_OPTIONS_BYTE_MESSAGE | TribesConstants.MSG_ORDER_OPTION | TribesConstants.AT_MOST_ONCE_OPTION); if (log.isDebugEnabled()) { log.debug("Sent " + cmd + " to " + TribesUtil.getName(member)); } } } catch (NotSerializableException e) { String message = "Could not send command message to " + TribesUtil.getName(member) + " since it is not serializable."; log.error(message, e); throw new ClusteringFault(message, e); } catch (ChannelException e) { log.error("Could not send message to " + TribesUtil.getName(member)); ChannelException.FaultyMember[] faultyMembers = e.getFaultyMembers(); log.error("Member " + TribesUtil.getName(member) + " is faulty", faultyMembers[0].getCause()); } catch (Exception e) { String message = "Could not send message to " + TribesUtil.getName(member) + ". Reason " + e.getMessage(); log.warn(message, e); } } }