1.JMS
   JAVA 消息服务(JMS)定义了Java 中访问消息中间件的接口。JMS 只是接口，并没有给予实现，实现JMS 接口的消息中间件称为JMS Provider，iLink实现了JMS接口，用户可以通过使用JMS接口，在iLink中进行JMS编程。 iLink支持JMS1.0.2版本。

2.JMS接口描述
   JMS 支持两种消息类型PTP 和Pub/Sub，分别称作：PTP Domain 和Pub/Sub Domain，这两种接口都继承统一的JMS父接口，JMS 主要接口如下所示：

MS父接口 PTP Pub/Sub ConnectionFactory QueueConnectionFactory TopicConnectionFactory Connection QueueConnection TopicConnection Destination Queue Topic Session QueueSession TopicSession MessageProducer QueueSender TopicPublisher MessageConsumer QueueReceiver,QueueBrowse r TopicSubscriber

                  
   ConnectionFactory ：连接工厂，JMS 用它创建连接
   Connection ：JMS 客户端到JMS Provider 的连接
   Destination ：消息的目的地
   Session： 一个发送或接收消息的线程
   MessageProducer： 由Session 对象创建的用来发送消息的对象
   MessageConsumer： 由Session 对象创建的用来接收消息的对象

3.JMS消息模型
JMS 消息由以下几部分组成：消息头，属性，消息体。
  
3.1 消息头(Header) - 消息头包含消息的识别信息和路由信息，消息头包含一些标准的属性如：JMSDestination,JMSMessageID 等。

消息头  由谁设置 JMSDestination send 或 publish 方法 JMSDeliveryMode send 或 publish 方法 JMSExpiration send 或 publish 方法 JMSPriority send 或 publish 方法 JMSMessageID send 或 publish 方法 JMSTimestamp send 或 publish 方法 JMSCorrelationID 客户 JMSReplyTo 客户 JMSType 客户 JMSRedelivered JMS Provider

    <[ServletContext(id=18489944,name=EBLGWeb,context-path=/)]: Deployment descriptor "/WEB-INF/bhr-tags-pagination.tld" is malformed. Check against the DTD: Content is not allowed in prolog. (line 1, column 1).>
    <[ServletContext(id=18489944,name=EBLGWeb,context-path=/)]: Error while parsing the Tag Library Descriptor at "/WEB-INF/bhr-tags-pagination.tld".
org.xml.sax.SAXException: [HTTP:101248][ServletContext(id=18489944,name=EBLGWeb,context-path=/)]: Deployment descriptor "/WEB-INF/bhr-tags-pagination.tld" is malformed. Check against the DTD: Content is not allowed in prolog. (line 1, column 1).
        at weblogic.apache.xerces.parsers.DOMParser.parse(DOMParser.java:285)
        at weblogic.apache.xerces.jaxp.DocumentBuilderImpl.parse(DocumentBuilderImpl.java:201)
        at weblogic.servlet.jsp.dd.JSPEntityResolver.load(JSPEntityResolver.java:81)
        at weblogic.servlet.jsp.dd.JSPEntityResolver.load(JSPEntityResolver.java:96)
        at weblogic.servlet.internal.WebAppHelper.registerTagLibListeners(WebAppHelper.java:293)
        at weblogic.servlet.internal.WebAppServletContext.activateFromDescriptors(WebAppServletContext.java:2530)
        at weblogic.servlet.internal.WebAppServletContext.activate(WebAppServletContext.java:6163)
        at weblogic.servlet.internal.WebAppServletContext.setActive(WebAppServletContext.java:6141)
        at weblogic.servlet.internal.WebAppModule.activate(WebAppModule.java:836)
        at weblogic.j2ee.J2EEApplicationContainer.activateModule(J2EEApplicationContainer.java:3322)
        at weblogic.j2ee.J2EEApplicationContainer.activate(J2EEApplicationContainer.java:2201)
        at weblogic.j2ee.J2EEApplicationContainer.activate(J2EEApplicationContainer.java:2174)
        at weblogic.j2ee.J2EEApplicationContainer.activate(J2EEApplicationContainer.java:2122)
        at weblogic.management.deploy.slave.SlaveDeployer$Application.setActivation(SlaveDeployer.java:3099)
        at weblogic.management.deploy.slave.SlaveDeployer.setActivationStateForAllApplications(SlaveDeployer.java:1768)
        at weblogic.management.deploy.slave.SlaveDeployer.resume(SlaveDeployer.java:351)
        at weblogic.management.deploy.DeploymentManagerServerLifeCycleImpl.resume(DeploymentManagerServerLifeCycleImpl.java:229)
        at weblogic.t3.srvr.SubsystemManager.resume(SubsystemManager.java:136)
        at weblogic.t3.srvr.T3Srvr.resume(T3Srvr.java:965)
        at weblogic.t3.srvr.T3Srvr.run(T3Srvr.java:360)
        at weblogic.Server.main(Server.java:32)
>

是由于某些文本编辑器（UltraEdit）存文本的时候产生的问题。可以使用text pad, word pad编辑XML格式的文件。

通过HTTP提交EDI请求,当EDI处理时间超过了20分钟后,就会看到在另一个weblogic server也接收到了这个EDI请求,重新处理这个报文.
如果报文处理时间更长,比如超过了50分钟,就会发现这个报文被处理了3遍或5遍.

When the Apache HTTP Server Plug-In attempts to connect to WebLogic Server, the plug-in uses several configuration 
parameters to determine how long to wait for connections to the WebLogic Server host and, after a connection is
established, how long the plug-in waits for a response. If the plug-in cannot connect or does not receive a response, 
the plug-in attempts to connect and send the request to other WebLogic Server instances in the cluster. If the 
connection fails or there is no response from any WebLogic Server in the cluster, an error message is sent.


响应等待时间参数WLIOTimeoutSecs (http://e-docs.bea.com/wls/docs81/plugins/plugin_params.html#1149781.
按照BEA 推荐的，这个值应该设得大一些, 这个参数的缺省值为300s. 见下面：
<Location /EDIHandler>
         SetHandler weblogic-handler
         WebLogicCluster apc_app1wls1:7011,apc_app1wls2:7011
         KeepAliveEnabled ON
         WLIOTimeoutSecs 7200
</Location>

Recently found, there is a memory leak bug for list cell renderer in both JDK 1.4.x and JDK 5 (don’t know whether has the same bug in earlier JDK). The component returned from getListCellRendererComponent() method could not be GC, and all its referenced objects also could not be GC. Unfortunately, this bug is only fixed in JDK 6.

So currently, if a JList use the ListCellRenderer, but only holds a little resource (eg: the JList only has little items, and the component is returned from ListCellRenderer is a simple JLable), you may not care about the memory leak.

But if a JList use the ListCellRenderer, and holds a large resource, you should remember to use the following way to avoid memory leak.

Work Around: Subclass JList and invoke removeAll after painting is done:

       public class xxxList extends JList {

            private CellRendererPane renderer;

            private CellRendererPane getRenderer() {

                if (renderer == null) {

                    for (int i=0; i<getComponents().length; i++) {

                                          Component c  = getComponents()[i];

                        if (c instanceof CellRendererPane) {

                            renderer = (CellRendererPane)c;

                            break;

                        }

                    }

                }

                return renderer;

            }

            protected void paintComponent(Graphics g) {

                super.paintComponent(g);

                CellRendererPane renderer = getRenderer();

                if (renderer != null) {

                    renderer.removeAll();

                }

            }

Please note that in the state classes, if a method is supported by stateA and not supported by stateB. 
Then, in stateB, the method body will throw an exception (IllegalArgumentException) to indicate that coder call the wrong method in the wrong state.

Example, in VesselPlanView.java, public boolean addStowage(...).  This method is only meaningful to stowageView.

public boolean addStowage(IlvManager manager, List transformList, IlvGraphic stowage, String stadBayN,
                              boolean isSelect) {
        throw new IllegalArgumentException(
                "GrVessel::addStowage-->be sure the vessel at stowage view!");
    }


Hence, in PlanView, the method body will throw exception.

Just to share with you a better way to code.