spring 框架的一个技术点IOC

梦里梦外; 2022-06-11 01:24 55阅读 0赞

写一个普通的实体类

package com.zhihao.bean;
    
    public class User {
    
    	private int id;
    	private String name;
    	private String pwd;
    	public int getId() {
    		return id;
    	}
    	public void setId(int id) {
    		this.id = id;
    	}
    	public String getName() {
    		return name;
    	}
    	public void setName(String name) {
    		this.name = name;
    	}
    	public String getPwd() {
    		return pwd;
    	}
    	public void setPwd(String pwd) {
    		this.pwd = pwd;
    	}
    	
    	public String say(){
    		return "[name:"+name+";pwd"+pwd+"]";
    	}
    }

用一个文件myBean.xml把这个实体类注册

<?xml version="1.0" encoding="UTF-8"?>
    <beans xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    	xmlns="http://www.springframework.org/schema/beans"
    	xmlns:aop="http://www.springframework.org/schema/aop"
    	xmlns:context="http://www.springframework.org/schema/context"
    	xmlns:tx="http://www.springframework.org/schema/tx"
    	xmlns:cache="http://www.springframework.org/schema/cache"
    	xmlns:p="http://www.springframework.org/schema/p"
    	xsi:schemaLocation="http://www.springframework.org/schema/beans
    	http://www.springframework.org/schema/beans/spring-beans-4.2.xsd 
    	http://www.springframework.org/schema/aop
     http://www.springframework.org/schema/aop/spring-aop-4.2.xsd
     http://www.springframework.org/schema/context
     http://www.springframework.org/schema/context/spring-context-4.2.xsd 
     http://www.springframework.org/schema/tx
     http://www.springframework.org/schema/tx/spring-tx-4.2.xsd
     http://www.springframework.org/schema/cache
     http://www.springframework.org/schema/cache/spring-cache-4.2.xsd">
      
     
        <bean id="user" class="com.zhihao.bean.User" scope="singleton">  
            <property name="name">  
                <value>yang</value>  
            </property> 
            <property name="pwd">  
                <value>123456</value>  
            </property>   
        </bean>  
    </beans>

在web.xml里面把这个配置文件myBean.xml 包含进来

<?xml version="1.0" encoding="UTF-8"?>
    <web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" id="WebApp_ID" version="3.0">
    	<display-name>testAOP</display-name>
    	
    	<listener>
    		<description>Spring监听器</description>
    		<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
    	</listener>
    
    	<context-param>
    		<param-name>contextConfigLocation</param-name>
    		<param-value>classpath:myBean.xml</param-value>
    	</context-param>
    
    	<servlet>
    		<servlet-name>springmvc</servlet-name>
    		<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
    		<init-param>
    			<param-name>contextConfigLocation</param-name>
    			<param-value>/WEB-INF/springmvc-servlet.xml</param-value>
    		</init-param>
    		
    	</servlet>
    	<servlet-mapping>
    		<servlet-name>springmvc</servlet-name>
    		<url-pattern>/</url-pattern>
    	</servlet-mapping>
    
    
    	<welcome-file-list>
    		<welcome-file>index.html</welcome-file>
    		<welcome-file>index.htm</welcome-file>
    		<welcome-file>index.jsp</welcome-file>
    		<welcome-file>default.html</welcome-file>
    		<welcome-file>default.htm</welcome-file>
    		<welcome-file>default.jsp</welcome-file>
    	</welcome-file-list>
    </web-app>

使用方法

package com.good.controller;
    
    import java.util.ArrayList;
    import java.util.List;
    
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.context.ApplicationContext;
    import org.springframework.context.support.ClassPathXmlApplicationContext;
    import org.springframework.stereotype.Controller;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.ResponseBody;
    
    import com.zhihao.bean.User;
    
    
    @Controller
    public class YamuController {
    	
    	@Autowired
    	User user;
    
    	@ResponseBody
    	@RequestMapping("/user")
    	public List user(){
    		/*ApplicationContext ct = new ClassPathXmlApplicationContext("/myBean.xml");
    		User user = (User)ct.getBean("user");*/
    		List list = new ArrayList();
    		list.add("ya mu");
    		list.add(user.say());
    		System.out.println("在controller 进行业务处理，数据库的增删改查等等。。");
    		return list;
    	} 
    }

这样就可以使用，用到了Spring的IOC技术。值得注意的是，在web.xml 里面，如果没有Spring 监听器 org.springframework.web.context.ContextLoaderListener，配置文件myBean.xml 不能产生作用。