本教程架构当前较流行的 Java 技术：
Spring Boot、MVC 、Security + Mybatis + Mysql + Thymeleaf
后台我们仍采用通常分层方式：
Controller -> Service -> Dao（这里是 Mybatis 的 Mapper）
创建以下包：
- com.example.demo.controller
- com.example.demo.service
- com.example.demo.entity
- com.example.demo.mapper
追加 Entity 类：
package com.example.demo.entity;
import java.io.Serializable;
public class User implements Serializable {
private static final long serialVersionUID = 1L;
private Long id;
private String username;
private String password;
public Long getId() {
return id;
}
public void setId(Long id) {
this.id = id;
}
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
}
package com.example.demo.entity;
import java.io.Serializable;
public class Shirt implements Serializable {
private static final long serialVersionUID = 1L;
private String name;
private int size;
private String color;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getSize() {
return size;
}
public void setSize(int size) {
this.size = size;
}
public String getColor() {
return color;
}
public void setColor(String color) {
this.color = color;
}
}
追加 Mapper 类：
package com.example.demo.mapper;
import org.apache.ibatis.annotations.Mapper;
import com.example.demo.entity.User;
@Mapper
public interface UserMapper {
User fetchUserByUsername(String username);
}
package com.example.demo.mapper;
import java.util.List;
import org.apache.ibatis.annotations.Mapper;
import com.example.demo.entity.Shirt;
@Mapper
public interface ShirtMapper {
List<Shirt> fetchAll();
}
追加 Service 类：
package com.example.demo.service;
import java.util.List;
import com.example.demo.entity.Shirt;
public interface ShirtService {
List<Shirt> fetchAll();
}
package com.example.demo.service;
import java.util.List;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import com.example.demo.entity.Shirt;
import com.example.demo.mapper.ShirtMapper;
@Service("shirtService")
public class ShirtServiceImpl implements ShirtService {
@Autowired
private ShirtMapper shirtMapper;
@Override
public List<Shirt> fetchAll() {
return shirtMapper.fetchAll();
}
}
追加 Controller 类：
package com.example.demo.controller;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;
import com.example.demo.service.ShirtService;
@Controller
public class ShirtController {
@Autowired
private ShirtService shirtService;
@RequestMapping("/admin")
public String findAll(Model model){
model.addAttribute("shirts", shirtService.fetchAll());
return "shirts";
}
}
resources/mapper 下追加 Mapper XML 文件：
UserMapper.xml
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd" >
<mapper namespace="com.example.demo.mapper.UserMapper">
<select id="fetchUserByUsername" resultType="User">
SELECT * FROM `users` WHERE username = #{username}
</select>
</mapper>
ShirtMapper.xml
<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd" > <mapper namespace="com.example.demo.mapper.ShirtMapper"> <select id="fetchAll" resultType="Shirt"> SELECT * FROM `shirts` </select> </mapper>
resources/templates 下追加 shirts.html 文件：
<!DOCTYPE HTML>
<html xmlns:th="http://www.thymeleaf.org">
<head>
<title>Shirts</title>
<meta http-equiv="Content-Type" content="text/html;charset=UTF-8"/>
</head>
<body>
<table>
<tr>
<th>Name</th>
<th>Size</th>
<th>Color</th>
</tr>
<tr th:each="shirt : ${shirts}">
<td th:text="${shirt.name}"></td>
<td th:text="${shirt.size}"></td>
<td th:text="${shirt.color}"></td>
</tr>
</table>
</body>
</html>
