学步园

初次使用SSH时发现很多朋友在使用

Java代码 

1. ApplicationContext context = newClassPathXmlApplicationContext("applicationContext.xml");  

ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");

获取ApplicationContext对象，进过自己测试这段代码适合C/S程序，在javaweb中这样获取ApplicationContext对象是很慢的。每次去getBean(”beanid“)时都会去加载applicationContext.xml"，这样效率很低的。 

Spring中提供了获取ApplicationContext对象的接口，在org.springframework.context.ApplicationContextAware中我们只需实现ApplicationContextAware接口的setApplicationContext方法，然后Spring的配置文件applicationContext.xml中注册实现ApplicationContextAware接口的类的类，并用静态的ApplicationContext变量把ApplicationContext保存下来，并在web.config中加上以下代码在网站启动时加载到内存中，然后就可以随心所欲的使用静态的ApplicationContext了。 


继承接口代码： 

Java代码 

1. package com.ssh.springfactory;  

2. import org.springframework.beans.BeansException;  

3. import org.springframework.context.ApplicationContext;  

4. import org.springframework.context.ApplicationContextAware;  

5. publicclass SpringFactory implements ApplicationContextAware{  

6. privatestatic ApplicationContext context;  

7. @Override

8. publicvoid setApplicationContext(ApplicationContext applicationContext)  

9. throws BeansException {  

10. this.context=applicationContext;  

11.    }  

12. publicstatic Object getObject(String id) {  

13.        Object object = null;  

14.        object = context.getBean(id);  

15. return object;  

16.    }  

17. }  

package com.ssh.springfactory;
import org.springframework.beans.BeansException;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
public class SpringFactory implements ApplicationContextAware{

private static ApplicationContext context;

@Override
public void setApplicationContext(ApplicationContext applicationContext)
throws BeansException {
this.context=applicationContext;
}


public static Object getObject(String id) {
Object object = null;
object = context.getBean(id);
return object;
}
}

注册对象，因为SpringFactory继承了ApplicationContextAware接口，我们在applicationContext.xml中注册该类： 

Java代码 

1. <bean id="springfactory"class="com.ssh.springfactory.SpringFactory"></bean>
    

<bean id="springfactory" class="com.ssh.springfactory.SpringFactory"></bean>

在web.config中初始化Spring容器Ioc： 

Java代码 

1. <listener>  

2.    <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>  

3. </listener>  

4. <context-param>  

5.    <param-name>contextConfigLocation</param-name>  

6.    <param-value>/WEB-INF/applicationContext.xml</param-value>  

7. </context-param>  

<listener>
<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>
<context-param>
<param-name>contextConfigLocation</param-name>
<param-value>/WEB-INF/applicationContext.xml</param-value>
</context-param>

然后就可以随心所欲的使用SpringFactory中的getObject方法了： 

Java代码 

1. publicstatic Object getObject(String id) {  

2.    Object object = null;  

3.    object = context.getBean(id);  

4. return object;  

5. }  

public static Object getObject(String id) {
Object object = null;
object = context.getBean(id);
return object;
}

这样就不会再每次去获得对象时去new IOC对象了： 

Java代码 

1. ApplicationContext context = newClassPathXmlApplicationContext("applicationContext.xml");  

ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");

你们也可以自己去断点ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");这段代码，用的时间不是一般的长……^_^.