Spring Boot（三）： 集成Mybatis和Druid实现增删改查

查了很多教程和博客，基本都是把Spring Boot和Spring Data JPA放在一起用，个人用不惯JPA，所以直接Mybatis了，毕竟现在大部分人用的都是Mybatis，这章主要是写一个基础表的增删改查

首先搭建一个Spring Boot项目，项目结构和启动类如下

然后是pom.xml引入我们需要的包

	4.0.0

	pers.hong
	demo
	0.0.1-SNAPSHOT
	jar

	demo
	Demo project for Spring Boot

	
		org.springframework.boot
		spring-boot-starter-parent
		2.0.4.RELEASE
		 
	

	
		UTF-8
		UTF-8
		1.8
	

	
		
			org.springframework.boot
			spring-boot-starter-web
		
		
			org.springframework.boot
			spring-boot-devtools
			runtime
		
		
			org.springframework.boot
			spring-boot-starter-test
			test
		
		
			org.mybatis.spring.boot
			mybatis-spring-boot-starter
			1.3.1
		
		
		
			com.github.pagehelper
			pagehelper-spring-boot-starter
			1.2.3
		
		
		
			mysql
			mysql-connector-java
			5.1.38
		
		
		
			com.alibaba
			druid-spring-boot-starter
			1.1.9
		
		
		
			org.apache.commons
			commons-lang3
			3.6
		
	

	
		
			
				org.springframework.boot
				spring-boot-maven-plugin
			
		
	

 数据库字段也很简单，主键设为自增

然后新建实体类User，同时生成两个构造器和toString方法

package pers.hong.demo.entity;

/**
 * @Description:
 * @Auther: hong
 * @Date: 2018/8/9/009 16:22
 */
public class User {
    private Integer id;
    private String name;
    private String password;
    private String email;

     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 getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }

    public User(Integer id, String name, String password, String email) {
        this.id = id;
        this.name = name;
        this.password = password;
        this.email = email;
    }

    public User() {
    }

    @Override
    public String toString() {
        return "User{" +
                "id=" + id +
                ", name='" + name + '\'' +
                ", password='" + password + '\'' +
                ", email='" + email + '\'' +
                '}';
    }
}

接下来写Dao层的代码，在写Dao层代码前，要先对yml文件进行配置

上面被注释掉的是不使用Druid连接池时的连接数据库的写法，下面除了原先的数据库配置，还有Druid的各项配置，包括最大最小连接数等（官方文档写的十分详细，这里就不细说了），然后是mybatis的配置，mapper-Location是存放mybatis的xml文件的路径，config-Location是mybatis配置文件的路径，type-aliases-package是指别名对应的实体类，配置了这个在config文件里就可以不用配置别名了，默认是小写，比如实体类User，别名就是user

mybatis的配置文件如下，配置了数据类型的别名

然后是Mapper接口和xml文件，增删改查基础方法

@Mapper
public interface UserMapper {
    List getUserById(@Param("id") Integer id);
    List getAllUser();
    void updateUserEmailById(@Param("id") Integer id);
    void deleteUserById(@Param("id") Integer id);
    void insertUser(User user);
}

    
        
        
        
        
    
    
        id,name,password,email
    
    
        INSERT INTO t_user
        (name,password,email)
        VALUE
        (#{name},#{password},#{email})
    
    
        UPDATE t_user
        SET
        name = #{name}
        password = #{password}
        email = #{email}
    
    
        DELETE FROM t_user
        WHERE id = #{id}
    
    
        SELECT
        
        FROM t_user
        WHERE id = #{id}
    
    
        SELECT
        
        FROM t_user
    

然后是service和实现层的代码，其实这一步没什么太大必要，因为demo没有做什么业务操作，但是为了后面对项目进行扩展，就先写着了

public interface UserService {
    List getAllUsers();
    List getUserById(@Param("id") Integer id);
    void updateUserEmailById(@Param("id") Integer id);
    void deleteUserById(@Param("id") Integer id);
    void insertUser(User user);
}

----------------------------------------------------------

@Service
public class UserServiceImpl implements UserService {
    @Autowired
    private UserMapper userMapper;

    @Override
    public List getAllUsers() {
        return userMapper.getAllUser();
    }

    @Override
    public List getUserById(Integer id) {
        return userMapper.getUserById(id);
    }

    @Override
    public void updateUserEmailById(Integer id) {
        userMapper.updateUserEmailById(id);
    }

    @Override
    public void deleteUserById(Integer id) {
        userMapper.deleteUserById(id);
    }

    @Override
    public void insertUser(User user) {
        userMapper.insertUser(user);
    }
}

最后是controller层

package pers.hong.demo.controller;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;
import pers.hong.demo.entity.User;
import pers.hong.demo.service.UserService;

import java.util.ArrayList;
import java.util.List;

/**
 * @Description:
 * @Auther: hong
 * @Date: 2018/8/9/009 17:03
 */
@RestController
public class UserController {
    @Autowired
    private UserService userService;

    @RequestMapping(value = "/getAllUser",method = RequestMethod.GET)
    public List getAllUser(){
        List resultList = new ArrayList<>();
        resultList = userService.getAllUsers();
        return resultList;
    }

    @RequestMapping(value = "/getUserById/{id}",method = RequestMethod.GET)
    public List getUser(@PathVariable Integer id){
        List resultList = new ArrayList<>();
        resultList = userService.getUserById(id);
        return resultList;
    }

    @RequestMapping(value = "/updateUserById")
    public void updateUser(@PathVariable Integer id){
        userService.updateUserEmailById(id);
    }

    @RequestMapping(value = "/deleteUserById/{id}")
    public void deleteUser(@PathVariable Integer id){
        userService.deleteUserById(id);
    }

    @RequestMapping(value = "/insertUser")
    public void insertUser(User user){
        userService.insertUser(new User(null,"qqq","qqq","qqq"));
    }
}

基本增删改查就完成了，让我们在浏览器中测试一下

下一章用Vue写下界面，不然修改删除都不好测OAO