Spring是一个完整的J2EE框架和解决方案,完整并且模块化,你可以用的他的全部也可以只用他的一部分特性,Spring 包含 IoC, AOP, 事务处理,ORM, 也包括一个简单的MVC框架.
用Spring,自我感觉,可以使你的代码至少节约30%,它的很多template很不错的,比如简单封装后的jdbctemplate,jmstemplate等。
ioc用后就会爱不释手,它让你的代码风格完全改观。以前我要产生个对象,绝大多数时候只回想到new一个对象,而用spring的ioc,beanfactory,只需要配置一个xml文件即可。这种方式实现了松偶合,对单元测试非常有利。
还有它的aop,也是很不错的,
用spring的感觉,正如它的名字一样:如沐春风.
关于spring中的jms,最近一个项目用到,刚好研究了一下,在这里做一个整理备份.在此感谢同事Eric的帮助.
spring把jms进行了简单的封装,用它的JmsTemplate可以很方便的发送和接收消息,并且资源的管理都由template来管理了.
1:在web.xml文件中配置一个spring用的上下文:
<
context-param
>
<
param-name
>
contextConfigLocation
</
param-name
>
<
param-value
>
/WEB-INF/jmsconfig.xml
</
param-value
>
</
context-param
>
jmsconfig.xml用来装配jms,内容如下:
<?
xml version="1.0" encoding="UTF-8"
?>
<!
DOCTYPE beans PUBLIC "-//SPRING/DTD BEAN/EN" "http://www.springframework.org/dtd/spring-beans.dtd"
>
<
beans
>
<
bean
id
="jmsConnectionFactory"
class
="org.springframework.jndi.JndiObjectFactoryBean"
>
<
property
name
="jndiName"
>
<
value
>
jms/Ntelagent/RequestQCF
</
value
>
</
property
>
</
bean
>
<
bean
id
="destination"
class
="org.springframework.jndi.JndiObjectFactoryBean"
>
<
property
name
="jndiName"
>
<
value
>
jms/Ntelagent/RequestQ
</
value
>
</
property
>
</
bean
>
<
bean
id
="jmsConnectionFactoryForReceive"
class
="org.springframework.jndi.JndiObjectFactoryBean"
>
<
property
name
="jndiName"
>
<
value
>
jms/Ntelagent/ResponseQCF
</
value
>
</
property
>
</
bean
>
<
bean
id
="destinationForReceive"
class
="org.springframework.jndi.JndiObjectFactoryBean"
>
<
property
name
="jndiName"
>
<
value
>
jms/Ntelagent/ResponseQ
</
value
>
</
property
>
</
bean
>
<
bean
id
="jmsTemplate"
class
="org.springframework.jms.core.JmsTemplate102"
>
<
property
name
="connectionFactory"
>
<
ref
bean
="jmsConnectionFactory"
/>
</
property
>
<
property
name
="defaultDestination"
>
<
ref
bean
="destination"
/>
</
property
>
<
property
name
="messageConverter"
>
<
ref
bean
="jmsTrxConverter"
/>
</
property
>
<
property
name
="receiveTimeout"
>
<
value
>
1
</
value
>
</
property
>
</
bean
>
<
bean
id
="jmsTemplateForReceive"
class
="org.springframework.jms.core.JmsTemplate102"
>
<
property
name
="connectionFactory"
>
<
ref
bean
="jmsConnectionFactoryForReceive"
/>
</
property
>
<
property
name
="defaultDestination"
>
<
ref
bean
="destinationForReceive"
/>
</
property
>
<
property
name
="messageConverter"
>
<
ref
bean
="jmsTrxConverter"
/>
</
property
>
<
property
name
="receiveTimeout"
>
<
value
>
1
</
value
>
</
property
>
</
bean
>
<
bean
id
="jmsTrxConverter"
class
="co.transport.jms.JmsTransactionConverter"
>
<
property
name
="rspQueue"
>
<
ref
bean
="destinationForReceive"
/>
</
property
>
</
bean
>
<
bean
id
="jmsRequestTransport"
class
="co.transport.jms.JmsRequestTransport"
>
<
property
name
="jmsTemplate"
>
<
ref
bean
="jmsTemplate"
/>
</
property
>
<
property
name
="jmsTemplateForReceive"
>
<
ref
bean
="jmsTemplateForReceive"
/>
</
property
>
</
bean
>
</
beans
>
其中:
jmsConnectionFactory为jms连接工厂,属性jndiName的value为server服务配置的jndi名称.
destination为消息队列,属性jndiName为消息队列的jndi名称.
jmsTemplate为配置spring消息模版:采用JmsTemplate102(如果你的JMS实现符合JMS规范1.1版,则应该使用JmsTemplate),其中的messageConverter属性配置了一个消息转换器,因为通常消息在发送前和接收后都需要进行一个前置和后置处理,转换器便进行这个工作。
由于我的sendQueue很receiveRueue是不同的queue,所以我配置了两个jmsTemplate:
jmsTemplateForReceive负责接收消息,jmsTemplate负责发发送消息.
发送消息的代码很简单:
jmsTemplate.convertAndSend(request);
接收消息也很简单:
Object obj = jmsTemplate.receiveAndConvert();
如果需要用一个过滤器接收特定的消息,则:
Object obj = this.jmsTemplateForReceive.receiveSelectedAndConvert(this.messageSelector);
发送和接收消息的class如下:
public
class
JmsRequestTransport
implements
RequestTransport
...
{
private JmsTemplate jmsTemplate;
private JmsTemplate jmsTemplateForReceive;
private String messageSelector;
private String destinationName;
public void setJmsTemplate(JmsTemplate template)...{
this.jmsTemplate = template;
}
public void request(Object request) ...{
jmsTemplate.convertAndSend(request);
}
public Object receive() ...{
System.out.println("in JmsRequestTransport: destinationName = " + this.jmsTemplateForReceive.getDefaultDestinationName());
System.out.println("in JmsRequestTransport: messageSelector = " + messageSelector);
Object obj = this.jmsTemplateForReceive.receiveSelectedAndConvert(this.messageSelector);
return obj;
}
public String getMessageSelector() ...{
return messageSelector;
}
public void setMessageSelector(String string) ...{
messageSelector = string;
}
public String getDestinationName() ...{
return destinationName;
}
public void setDestinationName(String string) ...{
destinationName = string;
}
public JmsTemplate getJmsTemplateForReceive() ...{
return jmsTemplateForReceive;
}
public void setJmsTemplateForReceive(JmsTemplate template) ...{
jmsTemplateForReceive = template;
}
}
要实现一个消息转换器,只需要实现MessageConverter接口,MessageConverter很简单,它只有两个方法需要实现:
public Object fromMessage(Message msg){}
public Message toMessage(Object obj, Session session) throws JMSException{}
fromMessage为接收消息后,对消息进行的转换(通常是把一个message转化为一个Object对象)
toMessage为发送消息前需要的转化(通常为把一个Object转化为一个message对象)
我的JmsTransactionConverter转换器如下:
public
class
JmsTransactionConverter
implements
MessageConverter
...
{
private Queue rspQueue;
public JmsTransactionConverter()...{}
public Object fromMessage(Message msg)...{
MessageBean msgBean = new MessageBean();
TextMessage massage = (TextMessage)msg;
try ...{
String str = massage.getText();
msgBean.setHead("HeadTest");
msgBean.setOutput(str);
msgBean.setStatus("success");
} catch (JMSException e) ...{
// TODO Auto-generated catch block
msgBean = null;
e.printStackTrace();
}
finally ...{
return msgBean;
}
}