JMS（Jboss Messaging）的一點使用心得（十一）Spring擴展應用-可自動重連的JmsMessageListenerContainer的另一種實現

爲什麼要做這個東西的原因就不說了，有興趣的話可以看看我的另一篇文章
[http://blog.csdn.net/supersue/archive/2007/11/24/1901203.aspx]

這種實現的原理是利用Jms Connection的ExceptionListen機制，只在發生錯誤的時候纔去Check和重連，系統開銷會小一些。

以下是代碼
DCJmsMessageListenerContainer.java

package jms.receiver;

import javax.jms.Connection;
import javax.jms.ExceptionListener;
import javax.jms.JMSException;

import org.springframework.jms.JmsException;
import org.springframework.jms.listener.serversession.ServerSessionMessageListenerContainer;


public class DCJmsMessageListenerContainer extends ServerSessionMessageListenerContainer
implements ExceptionListener ...{

    /** *//** interval */
    private long interval = 300000;

    private CheckConnectionThread checker;
    
    /** *//** ClassLoader */
    private ClassLoader classLoader;
    
    /** *//** ExceptionListener */
    private ExceptionListener exListener;

    public void setInterval(long interval) ...{
        this.interval = 60000 * interval;
    }

    public void setExListener(ExceptionListener exListener) ...{
        this.exListener = exListener;
    }

    @Override
    public void afterPropertiesSet() ...{
        super.afterPropertiesSet();
        this.classLoader = Thread.currentThread().getContextClassLoader();
    }

    @Override
    protected Connection createConnection() throws JMSException ...{
        Connection conn = super.createConnection();
        if (this.exListener == null) ...{
            conn.setExceptionListener(this);
        } else ...{
            conn.setExceptionListener(this.exListener);
        }
        return conn;
    }

    @Override
    public void destroy() ...{
        if (this.checker != null) ...{
            this.checker.shutdown();
            this.checker = null;
        }

        super.destroy();
    }

    public void refreshConnection() ...{
        try ...{
            this.logger.info(this.getBeanName() + " RefreshConnection Begin.");
            if (this.checker == null || !this.checker.isCheckRun()) ...{
                super.refreshSharedConnection();
                super.initialize();
            }
            this.logger.info(this.getBeanName() + " RefreshConnection Succeed.");
        } catch (JMSException e) ...{
            this.logger.error(this.getBeanName() + " [Digitalcinema JMS Failover]", e);
        }
    }

    public void onException(JMSException e) ...{
        this.logger.error(this.getBeanName() + " Connection Error: " + e.getMessage());
        if (this.checker != null) ...{
            this.checker.shutdown();
            this.checker = null;
        }

        this.checker = new CheckConnectionThread();
        this.checker.setDaemon(true);
        this.checker.setContextClassLoader(this.classLoader);
        this.checker.start();
    }

    public void handleException(JMSException e) ...{
        this.logger.error(this.getBeanName() + " Connection Error: " + e.getMessage());
        if (this.checker == null || !this.checker.isCheckRun()) ...{
            this.checker = new CheckConnectionThread();
            this.checker.setDaemon(true);
            this.checker.setContextClassLoader(this.classLoader);
            this.checker.start();
        }
    }

    private class CheckConnectionThread extends Thread ...{
        /** *//** checkRunFlg */
        private volatile boolean checkRunFlg = true;

        public void shutdown() ...{
            this.checkRunFlg = false;
            logger.info(DCJmsMessageListenerContainer.this.getBeanName()
                    + " CheckConnectionThread Stoped!");
            this.interrupt();
        }

        public boolean isCheckRun() ...{
            return this.checkRunFlg;
        }

        @Override
        public void run() ...{
            logger.info(DCJmsMessageListenerContainer.this.getBeanName()
                            + " CheckConnectionThread Started!");
            this.checkRunFlg = true;

            while (this.checkRunFlg) ...{
                try ...{
                    logger.info(DCJmsMessageListenerContainer.this.getBeanName() 
                                + " [Digitalcinema JMS Failover] Refresh Shared Connection");
                    DCJmsMessageListenerContainer.this.refreshSharedConnection();
                    logger.info(DCJmsMessageListenerContainer.this.getBeanName() 
                                + " [Digitalcinema JMS Failover] Container Initialize");
                    DCJmsMessageListenerContainer.this.initialize();
                    this.checkRunFlg = false;
                    break;
                } catch (JmsException e) ...{
                    logger.info(DCJmsMessageListenerContainer.this.getBeanName()
                                   + " [Digitalcinema JMS Failover]", e);
                    try ...{
                        Thread.sleep(interval);
                    } catch (InterruptedException ie) ...{
                        logger.error(DCJmsMessageListenerContainer.this.getBeanName() 
                                     + " [Digitalcinema JMS Failover]", ie);
                    }
                } catch (JMSException e) ...{
                    logger.info(DCJmsMessageListenerContainer.this.getBeanName()
                           + " [Digitalcinema JMS Failover]", e);
                    try ...{
                        Thread.sleep(interval);
                    } catch (InterruptedException ie) ...{
                        logger.error(DCJmsMessageListenerContainer.this.getBeanName() 
                                     + " [Digitalcinema JMS Failover]", ie);
                    }
                }
            }
        }
    }
}

在Spring的配置文件中可以這樣配置

    <bean id="exListenerContainerQueue" lazy-init="true" 
        class="jms.receiver.DCJmsMessageListenerContainer">
        <property name="connectionFactory" ref="myConnectionFactory" />
        <property name="destinationName" value="B" />
        <property name="messageListener" ref="messageListener" />
        <property name="sessionTransacted" value="true" />
    </bean>