Spring中IOC的Annotation案例（非底层）
Spring中IOC的Annotation实现：
此处特别注意每个类中注释的注解及相关文字说明，可以更好的理解Spring中IOC的Annotation实现！
首先beans.xml中需要引入 context 的schema：
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.2.xsd">
在XML中配置Spring对Annotation的相关配置：
<!-- 打开Spring的Annotation的支持 --> <context:annotation-config /> <!-- 设定Spring去哪些包中找Annotation --> <context:component-scan base-package="com.spring" />
完整的XML配置：
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.2.xsd"> <!-- 打开Spring的Annotation的支持 --> <context:annotation-config /> <!-- 设定Spring去哪些包中找Annotation --> <context:component-scan base-package="com.spring" /> </beans>
User实体类：
package com.spring.model;
public class User {
public User() {
super();
}
private int id;
private String username;
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
@Override
public String toString() {
return "User [id=" + id + ", username=" + username + "]";
}
public User(int id, String username) {
super();
this.id = id;
this.username = username;
}
}
IUserDao接口:
package com.spring.dao;
import com.spring.model.User;
public interface IUserDao {
public void add(User user);
public void delete(int id);
public User load(int id);
}
UserDao类：
package com.spring.dao;
import org.springframework.stereotype.Component;
import org.springframework.stereotype.Repository;
import com.spring.model.User;
//等于完成了<bean id="userDao" class="com.spring.dao.UserDao"/>
//@Component("userDao") //@Component公共的创建bean的Annotation
@Repository("userDao") //@Repository表示一般用于Dao的注入
public class UserDao implements IUserDao {
@Override
public void delete(int id) {
System.out.println("删除了"+id);
}
@Override
public User load(int id) {
System.out.println("load了User");
return null;
}
@Override
public void add(User user) {
System.out.println("添加了"+user);
}
}
IUserService接口：
package com.spring.service;
import com.spring.model.User;
public interface IUserService {
public void add(User user);
public void delete(int id);
public User load(int id);
}
UserService类：
package com.spring.service;
import javax.annotation.Resource;
import org.springframework.stereotype.Component;
import org.springframework.stereotype.Service;
import com.spring.dao.IUserDao;
import com.spring.model.User;
//@Component(value="userService")
@Service("userService") //业务层一般用@Service注入
public class UserService implements IUserService {
private IUserDao userDao;
public IUserDao getUserDao() {
return userDao;
}
//默认通过名称注入，在JSR330中提供了@Inject来注入
@Resource
public void setUserDao(IUserDao userDao) {
this.userDao = userDao;
}
@Override
public void add(User user) {
userDao.add(user);
}
@Override
public void delete(int id) {
userDao.delete(id);
}
@Override
public User load(int id) {
return userDao.load(id);
}
}
UserAction类：
package com.spring.action;
import javax.annotation.Resource;
import org.springframework.context.annotation.Scope;
import org.springframework.stereotype.Component;
import org.springframework.stereotype.Controller;
import com.spring.model.User;
import com.spring.service.IUserService;
//@Component("userAction")
@Controller("userAction") //MVC的控制层一般使用@Controller
@Scope("prototype") //设置多例
public class UserAction {
private User user;
private IUserService userService;
private int id;
public User getUser() {
return user;
}
public void setUser(User user) {
this.user = user;
}
public IUserService getUserService() {
return userService;
}
@Resource
public void setUserService(IUserService userService) {
this.userService = userService;
}
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public void add(){
userService.add(user);
}
public void delete(){
userService.delete(id);
}
public void load(){
userService.load(id);
}
}
测试类：
package com.spring.test;
import org.junit.Test;
import org.springframework.beans.factory.BeanFactory;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import com.spring.action.UserAction;
import com.spring.model.User;
public class TestSpring {
//创建Spring工厂
private BeanFactory beanFactory=new ClassPathXmlApplicationContext("beans.xml");
@Test
public void testUser(){
UserAction ua=beanFactory.getBean("userAction",UserAction.class);
User user=new User(1,"我叫spring");
ua.setUser(user);
ua.add();
//单例的时候添加相同的内容，多例添加为null
UserAction ua1=beanFactory.getBean("userAction",UserAction.class);
ua1.add();
}
}
运行结果及项目结果图：
