解释代码package com.xml; import org.mybatis.spring.annotation.MapperScan; import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; import org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration; import org.springframework.boot.autoconfigure.orm.jpa.HibernateJpaAutoConfiguration; @SpringBootApplication //指定mapper的包路径，省去@Mapper注解 @MapperScan("com.xml.mapper") public class App { public static void main(String[] args) { SpringApplication.run(App.class, args); } }

这段代码是一个Java类，位于com.xml包下。它使用了Spring Boot框架，@SpringBootApplication注解表示它是一个Spring Boot应用程序的入口类。

在这段代码中，还使用了@MapperScan注解，指定了Mapper接口所在的包路径，可以省略Mapper接口上的@Mapper注解。同时，还禁用了Spring Boot自动配置的数据源和JPA/Hibernate自动配置，因为这些配置在本应用程序中并不需要。

main方法是这个应用程序的入口，通过调用SpringApplication类的run方法来启动应用程序。

相关问题

使用代码案例详解tk.mybatis的使用

当使用tk.mybatis时，可以按照以下步骤进行操作：

1. 首先，在你的项目中添加tk.mybatis的依赖。可以在pom.xml文件中添加以下代码：

<dependency>
    <groupId>tk.mybatis</groupId>
    <artifactId>mapper-spring-boot-starter</artifactId>
    <version>版本号</version>
</dependency>

2. 创建一个实体类，该实体类对应数据库中的一张表。例如，创建一个名为User的实体类：

import javax.persistence.*;

@Table(name = "user")
public class User {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Integer id;

    private String username;

    private String password;

    // getters and setters
}

3. 创建一个Mapper接口，继承tk.mybatis.mapper.common.Mapper接口。例如，创建一个名为UserMapper的接口：

import tk.mybatis.mapper.common.Mapper;

public interface UserMapper extends Mapper<User> {
}

4. 在配置文件中配置Mapper扫描路径和数据库连接信息。例如，在application.properties文件中添加以下代码：

# 数据库连接信息
spring.datasource.url=jdbc:mysql://localhost:3306/db_name?useUnicode=true&characterEncoding=utf-8&useSSL=false
spring.datasource.username=root
spring.datasource.password=root

# Mapper扫描路径
mapper.scan-package=com.example.mapper

5. 在Service层中使用UserMapper进行数据库操作。例如，在UserService中注入UserMapper，并调用相应的方法：

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import tk.mybatis.mapper.entity.Example;

import java.util.List;

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

    public List<User> getAllUsers() {
        return userMapper.selectAll();
    }

    public User getUserById(Integer id) {
        return userMapper.selectByPrimaryKey(id);
    }

    public void addUser(User user) {
        userMapper.insertSelective(user);
    }

    public void updateUser(User user) {
        userMapper.updateByPrimaryKeySelective(user);
    }

    public void deleteUser(Integer id) {
        userMapper.deleteByPrimaryKey(id);
    }
}

以上就是使用tk.mybatis的基本操作步骤，通过继承Mapper接口，可以实现常见的数据库操作方法。你可以根据具体的需求进行扩展和定制。希望可以帮到你！

springmyboot+batis的代码写一个，带有依赖，yml配置，mapper.xml，entity，mapper，service，controller，application

.yml配置文件

spring:
  datasource:
    url: jdbc:mysql://localhost:3306/test?useUnicode=true&characterEncoding=utf-8&useSSL=false&serverTimezone=UTC
    username: root
    password: root
    driver-class-name: com.mysql.cj.jdbc.Driver
  jackson:
    date-format: yyyy-MM-dd HH:mm:ss
    time-zone: GMT+8
  servlet.multipart.max-file-size: 10MB
  servlet.multipart.max-request-size: 10MB
mybatis:
  type-aliases-package: com.example.demo.entity
  mapper-locations: classpath:mapper/*.xml

Mapper.xml文件

<?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="getUserById" parameterType="int" resultType="com.example.demo.entity.User">
        select * from user where id = #{id}
    </select>
    <select id="getUserList" resultType="com.example.demo.entity.User">
        select * from user
    </select>
    <insert id="addUser" parameterType="com.example.demo.entity.User">
        insert into user(username,password) values(#{username},#{password})
    </insert>
    <update id="updateUser" parameterType="com.example.demo.entity.User">
        update user set username=#{username},password=#{password} where id=#{id}
    </update>
    <delete id="deleteUser" parameterType="int">
        delete from user where id=#{id}
    </delete>
</mapper>

Entity文件

package com.example.demo.entity;

public class User {
    private int id;
    private String username;
    private String password;

    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;
    }

    public String getPassword() {
        return password;
    }

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

Mapper文件

package com.example.demo.mapper;

import com.example.demo.entity.User;

import java.util.List;

public interface UserMapper {
    User getUserById(int id);
    List<User> getUserList();
    void addUser(User user);
    void updateUser(User user);
    void deleteUser(int id);
}

Service文件

package com.example.demo.service;

import com.example.demo.entity.User;
import com.example.demo.mapper.UserMapper;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.List;

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

    public User getUserById(int id) {
        return userMapper.getUserById(id);
    }

    public List<User> getUserList() {
        return userMapper.getUserList();
    }

    public void addUser(User user) {
        userMapper.addUser(user);
    }

    public void updateUser(User user) {
        userMapper.updateUser(user);
    }

    public void deleteUser(int id) {
        userMapper.deleteUser(id);
    }
}

Controller文件

package com.example.demo.controller;

import com.example.demo.entity.User;
import com.example.demo.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;

import java.util.List;

@RestController
@RequestMapping("/user")
public class UserController {
    @Autowired
    private UserService userService;

    @GetMapping("/{id}")
    public User getUserById(@PathVariable int id) {
        return userService.getUserById(id);
    }

    @GetMapping("/")
    public List<User> getUserList() {
        return userService.getUserList();
    }

    @PostMapping("/")
    public void addUser(@RequestBody User user) {
        userService.addUser(user);
    }

    @PutMapping("/")
    public void updateUser(@RequestBody User user) {
        userService.updateUser(user);
    }

    @DeleteMapping("/{id}")
    public void deleteUser(@PathVariable int id) {
        userService.deleteUser(id);
    }
}

Application文件

package com.example.demo;

import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
@MapperScan("com.example.demo.mapper")
public class DemoApplication {

    public static void main(String[] args) {
        SpringApplication.run(DemoApplication.class, args);
    }

}