15.使用注解

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使用注解

Vo

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package com.course.vo;

public class User {

	private Integer id;
	private String name;
	private String address;
	
	public Integer getId() {
		return id;
	}
	public void setId(Integer id) {
		this.id = id;
	}
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	public String getAddress() {
		return address;
	}
	public void setAddress(String address) {
		this.address = address;
	}
	
	@Override
	public String toString() {
		return "User [id=" + id + ", name=" + name + ", address=" + address + "]";
	}	
}

Dao

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package com.course.dao;

import com.course.vo.User;

public interface UserDao {

	public User getUser(Integer id);
}
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package com.course.dao.impl;

import org.springframework.stereotype.Repository;

import com.course.dao.UserDao;
import com.course.vo.User;

@Repository
public class UserDaoImpl implements UserDao {

	@Override
	public User getUser(Integer id) {
		User user = new User();
		user.setId(id);
		user.setName("Tom" + id);
		user.setAddress("location" + id);
		return user;
	}

}

Service

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package com.course.service;

import com.course.vo.User;

public interface UserService {

	public User getUserInfo(Integer id);
}
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package com.course.service.impl;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import com.course.dao.UserDao;
import com.course.service.UserService;
import com.course.vo.User;

@Service
public class UserServiceImpl implements UserService {
	
	@Autowired
	private UserDao userDao;

	// set()
	public void setUserDao(UserDao userDao) {
		this.userDao = userDao;
	}

	@Override
	public User getUserInfo(Integer id) {
		User user = userDao.getUser(id);
		return user;
	}

}

Controller

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package com.course.controller;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;

import com.course.service.UserService;
import com.course.vo.User;

@Controller
public class UserController {

	@Autowired
	private UserService userService;
	
	// set()
	public void setUserService(UserService userService) {
		this.userService = userService;
	}

	public User getUserById(Integer id) {
		User user = userService.getUserInfo(id);
		return user;
	}
}

applicationContext.xml

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<?xml version="1.0" encoding="UTF-8"?>
<!-- 头文件 -->
<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.xsd">
        
	<!-- 
	<context:component-scan base-package="com.course.dao.impl"></context:component-scan>
	<context:component-scan base-package="com.course.service.impl"></context:component-scan>
	<context:component-scan base-package="com.course.controller"></context:component-scan>
	
	<context:component-scan base-package="com.course.dao.impl,com.course.service.impl,com.course.controller"></context:component-scan>
	 -->
	
	<context:component-scan base-package="com.course"></context:component-scan>
</beans>

测试类

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package com.test;

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

import com.course.controller.UserController;
import com.course.vo.User;

public class TestMain {

	public static void main(String[] args) {
		ApplicationContext applicationContext = new ClassPathXmlApplicationContext("classpath:applicationContext.xml");
		System.out.println(applicationContext);
		
		UserController userController = (UserController) applicationContext.getBean("userController");
		User user = userController.getUserById(1);
		System.out.println(user);
        // User [id=1, name=Tom1, address=location1]
	}
}

注解说明

注解 位置 作用
@Repository 数据访问层 创建对象
@Service 服务层 创建对象
@Controller 控制层 创建对象
@Component 任何位置 创建对象，当一个类没有确定的分类时，可以使用该注解
@Autowired 属性、方法、参数、构造方法 自动注入，当放在方法上时，注入对象与方法名无关，取决于参数名