采用JMS实现的聚合器
聚合器从某个通道接收竞标消息，把相关的竞标消息集中起来，并把有最低竞标价的消息发布给另一个通道。竞标消息通过拍卖ID属性关联起来，它相当于消息的关联标识符。
其中：
1.Aggregator包含接收消息、把消息集中起来并发送结果消息的逻辑。它通过aggregate接口与集合交互。
2.AuctionAggregate实现了Aggregate接口
3.Auction是已接收的相关竞标消息的集合。
4.Bid是一个便利类，用于储存与竞标有关的数据项
sendMessage类用来模拟发送拍卖消息：
Aggregate接口：
build.xml
其中：
1.Aggregator包含接收消息、把消息集中起来并发送结果消息的逻辑。它通过aggregate接口与集合交互。
2.AuctionAggregate实现了Aggregate接口
3.Auction是已接收的相关竞标消息的集合。
4.Bid是一个便利类，用于储存与竞标有关的数据项
sendMessage类用来模拟发送拍卖消息：
package com.foshanshop.ejb3.app;
import javax.jms.*;
import javax.jms.Queue;
import java.util.*;
import javax.naming.*;
public class sendMessage {
static String PROP_AUCTIONID="AuctionID";
static String ITEMID="ItemID";
static String VENDOR="Vendor";
static String PRICE="price";
/**
* @param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
QueueConnection conn=null;
QueueSession session=null;
try
{
Properties props=new Properties();
props.setProperty(Context.INITIAL_CONTEXT_FACTORY, "org.jnp.interfaces.NamingContextFactory");
props.setProperty(Context.PROVIDER_URL, "localhost:1099");
props.setProperty(Context.URL_PKG_PREFIXES, "org.jboss.naming:org.jnp.interfaces");
InitialContext ctx = new InitialContext(props);
QueueConnectionFactory factory=(QueueConnectionFactory)ctx.lookup("QueueConnectionFactory");
conn=factory.createQueueConnection();
session=conn.createQueueSession(false, QueueSession.AUTO_ACKNOWLEDGE);
Destination destination=(Queue)ctx.lookup("queue/FQueueA");
MessageProducer producer=session.createProducer(destination);
MapMessage msg=session.createMapMessage();
for(int i=0;i<3;i++)
{
String [] vendor={"cy","chenyuan","yuanchen"};
msg.setStringProperty(PROP_AUCTIONID,"123");
msg.setString(ITEMID, "1234");
msg.setString(VENDOR, vendor[i]);
msg.setDouble(PRICE, i+10);
producer.send(msg);
}
//producer.send(msg);
}
catch(Exception e)
{
System.out.println("queueSender main has a problem"+":"+e.toString());
}
}
}
Aggregate接口：
package com.foshanshop.ejb3.app;
import javax.jms.*;
public interface Aggregate {
public void addMessage(Message msg);
public boolean isComplete();
public Message getResultMessage();
}
package com.foshanshop.ejb3.app;
import javax.jms.Message;
import javax.jms.*;
import com.foshanshop.ejb3.bean.*;
public class AuctionAggregate implements Aggregate {
static String PROP_AUCTIONID="AuctionID";
static String ITEMID="ItemID";
static String VENDOR="Vendor";
static String PRICE="price";
private Session session;
private Auction auction;
public AuctionAggregate(Session session)
{
this.session=session;
auction=new Auction();
}
public void addMessage(Message msg) {
// TODO Auto-generated method stub
Bid bid=null;
if(msg instanceof MapMessage)
{
try
{
MapMessage mapmsg=(MapMessage)msg;
String auctionID=mapmsg.getStringProperty(PROP_AUCTIONID);
String itemID=mapmsg.getString(ITEMID);
String vendor=mapmsg.getString(VENDOR);
double price=mapmsg.getDouble(PRICE);
bid=new Bid(auctionID,itemID,vendor,price);
auction.addBid(bid);
}
catch(Exception e)
{
System.out.println(e.toString());
}
}
}
public Message getResultMessage() {
// TODO Auto-generated method stub
Bid bid=auction.getBestBid();
try
{
MapMessage msg=session.createMapMessage();
msg.setStringProperty(PROP_AUCTIONID,bid.getCorrelationID());
msg.setString(ITEMID, bid.getItemId());
msg.setString(VENDOR, bid.getVendorName());
msg.setDouble(PRICE, bid.getPrice());
return msg;
}
catch(Exception e)
{
System.out.println(e.toString());
}
return null;
}
public boolean isComplete() {
// TODO Auto-generated method stub
return auction.isComplete();
}
}
package com.foshanshop.ejb3.app;
import com.foshanshop.ejb3.bean.*;
import java.util.*;
public class Auction {
ArrayList bids=new ArrayList();
public void addBid(Bid bid)
{
bids.add(bid);
System.out.println(bids.size()+" Bids in auction.");
}
public boolean isComplete()
{
return(bids.size()>=3);
}
public Bid getBestBid()
{
Bid bestBid=null;
Iterator iter=bids.iterator();
if(iter.hasNext())
{
bestBid=(Bid)iter.next();
while(iter.hasNext())
{
Bid b=(Bid)iter.next();
if(b.getPrice()<bestBid.getPrice())
{
bestBid=b;
}
}
}
return bestBid;
}
}
package com.foshanshop.ejb3.bean;
import java.io.Serializable;
public class Bid implements Serializable {
/**
*
*/
private static final long serialVersionUID = -7678873060248075903L;
private String ItemId;
private String VendorName;
private double Price;
private String CorrelationID;
public Bid(String correlationID,String itemId,String vendorName,double price)
{
this.CorrelationID=correlationID;
this.ItemId=itemId;
this.VendorName=vendorName;
this.Price=price;
}
public String getCorrelationID()
{
return this.CorrelationID;
}
public void setCorrelationID(String correlationID)
{
this.CorrelationID=correlationID;
}
public String getItemId()
{
return this.ItemId;
}
public void setItemId(String itemId)
{
this.ItemId=itemId;
}
public String getVendorName()
{
return this.VendorName;
}
public void setVendorName(String vendorName)
{
this.VendorName=vendorName;
}
public double getPrice()
{
return this.Price;
}
public void setPrice(double price)
{
this.Price=price;
}
}
package com.foshanshop.ejb3.impl;
import java.util.*;
import javax.ejb.ActivationConfigProperty;
import javax.ejb.MessageDriven;
import javax.jms.Destination;
import javax.jms.Message;
import javax.jms.MapMessage;
import javax.jms.MessageListener;
import javax.jms.MessageProducer;
import javax.jms.Queue;
import javax.jms.QueueConnection;
import javax.jms.QueueConnectionFactory;
import javax.jms.QueueSession;
import javax.naming.Context;
import javax.naming.InitialContext;
import com.foshanshop.ejb3.app.*;
import java.util.*;
@MessageDriven(activationConfig={@ActivationConfigProperty(propertyName="destinationType",propertyValue="javax.jms.Queue"),
@ActivationConfigProperty(propertyName="destination",propertyValue="queue/FQueueA"),@ActivationConfigProperty(propertyName="acknowledgeMode",propertyValue="Auto-acknowledge")})
public class Aggregator implements MessageListener {
static final String PROP_CORRID="AuctionID";
Map activeAggregates=new HashMap();
QueueConnection conn=null;
QueueSession session=null;
public void onMessage(Message msg) {
// TODO Auto-generated method stub
try
{
Properties props=new Properties();
props.setProperty(Context.INITIAL_CONTEXT_FACTORY, "org.jnp.interfaces.NamingContextFactory");
props.setProperty(Context.PROVIDER_URL, "localhost:1099");
props.setProperty(Context.URL_PKG_PREFIXES, "org.jboss.naming:org.jnp.interfaces");
InitialContext ctx = new InitialContext(props);
QueueConnectionFactory factory=(QueueConnectionFactory)ctx.lookup("QueueConnectionFactory");
conn=factory.createQueueConnection();
session=conn.createQueueSession(false, QueueSession.AUTO_ACKNOWLEDGE);
//Destination destinationA=(Queue)ctx.lookup("queue/FQueueA");
Destination destinationB=(Queue)ctx.lookup("queue/FQueueB");
MessageProducer producer=session.createProducer(destinationB);
String correlationID=msg.getStringProperty(PROP_CORRID);
Aggregate aggregate=(Aggregate)activeAggregates.get(correlationID);
if(aggregate==null)
{
aggregate=new AuctionAggregate(session);
activeAggregates.put(correlationID, aggregate);
}
if(!aggregate.isComplete())
{
aggregate.addMessage(msg);
if(aggregate.isComplete())
{
MapMessage result=(MapMessage)aggregate.getResultMessage();
producer.send(result);
}
}
}
catch(Exception e)
{
System.out.println(e.toString());
}
}
}
package com.foshanshop.ejb3.impl;
import javax.ejb.ActivationConfigProperty;
import javax.ejb.MessageDriven;
import javax.jms.Message;
import javax.jms.MessageListener;
import javax.jms.MapMessage;
@MessageDriven(activationConfig={@ActivationConfigProperty(propertyName="destinationType",propertyValue="javax.jms.Queue"),
@ActivationConfigProperty(propertyName="destination",propertyValue="queue/FQueueB"),@ActivationConfigProperty(propertyName="acknowledgeMode",propertyValue="Auto-acknowledge")})
public class receiveResult implements MessageListener {
static String PROP_AUCTIONID="AuctionID";
static String ITEMID="ItemID";
static String VENDOR="Vendor";
static String PRICE="price";
public void onMessage(Message msg) {
// TODO Auto-generated method stub
try
{
if(msg instanceof MapMessage)
{
MapMessage mapmsg=(MapMessage)msg;
System.out.println(mapmsg.getString(ITEMID)+":"+mapmsg.getDouble(PRICE));
}
}
catch(Exception e)
{
System.out.println(e.toString());
}
}
}
build.xml
<?xml version="1.0"?>
<!-- ======================================================================= -->
<!-- EJB3 MessageDrivenBean build file -->
<!-- ======================================================================= -->
<project name="aggregator" default="ejbjar" basedir="..">
<property environment="env" />
<property name="app.dir" value="${basedir}\aggregator" />
<property name="src.dir" value="${app.dir}\src" />
<property name="jboss.home" value="${env.JBOSS_HOME}" />
<property name="jboss.server.config" value="default" />
<property name="build.dir" value="${app.dir}\build" />
<property name="build.classes.dir" value="${build.dir}\classes" />
<!-- Build classpath -->
<path id="build.classpath">
<fileset dir="${jboss.home}\client">
<include name="*.jar" />
</fileset>
<pathelement location="${build.classes.dir}" />
</path>
<!-- =================================================================== -->
<!-- Prepares the build directory -->
<!-- =================================================================== -->
<target name="prepare" depends="clean">
<mkdir dir="${build.dir}" />
<mkdir dir="${build.classes.dir}" />
</target>
<!-- =================================================================== -->
<!-- Compiles the source code -->
<!-- =================================================================== -->
<target name="compile" depends="prepare" description="编绎">
<javac srcdir="${src.dir}" destdir="${build.classes.dir}" debug="on" deprecation="on" optimize="off" includes="com/**">
<classpath refid="build.classpath" />
</javac>
</target>
<target name="ejbjar" depends="compile" description="创建EJB发布包">
<jar jarfile="${app.dir}\aggregator.jar">
<fileset dir="${build.classes.dir}">
<include name="com/foshanshop/ejb3/*.class" />
<include name="com/foshanshop/ejb3/impl/*.class" />
<include name="com/foshanshop/ejb3/bean/*.class" />
<include name="com/foshanshop/ejb3/app/*.class" />
</fileset>
</jar>
</target>
<target name="deploy" depends="ejbjar">
<copy file="${app.dir}\aggregator.jar" todir="${jboss.home}\server\${jboss.server.config}\deploy" />
</target>
<!-- =================================================================== -->
<!-- Cleans up generated stuff -->
<!-- =================================================================== -->
<target name="clean">
<delete dir="${build.dir}" />
<delete file="${jboss.home}\server\${jboss.server.config}\deploy\aggregator.jar" />
</target>
</project>