MyBatis+Spring框架全注解整合

1.pom.xml文件配置

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.1.9.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.example</groupId>
    <artifactId>mybatisdemo</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>mybatisdemo</name>
    <description>Demo project for Spring Boot</description>

    <properties>
        <java.version>1.8</java.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <!--spring+mybatis主要jar包-->
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>2.1.0</version>
        </dependency>

        <dependency>
            <!--lombok包，用于简化代码，注解省略setter，getter，默认构造方法等-->
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

2.配置数据源，直接在配置文件中配置数据源，可以使用properties文件或者yml文件

spring.datasource.url=jdbc:mysql://localhost:3306/test?serverTimezone=UTC
spring.datasource.username=root
spring.datasource.password=1234567890
spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver
#MySQL5用的驱动url是com.mysql.jdbc.Driver，MySQL6以后用的是com.mysql.cj.jdbc.Driver,
连接MySQL6(com.mysql.cj.jdbc.Driver)，需要指定时区serverTimezone

spring:
  datasource:
    url: jdbc:mysql://localhost:3306/test?serverTimezone=UTC
    password: root
    username: ******
    driver-class-name: com.mysql.cj.jdbc.Driver

3.实体类User

package com.example.mybatisdemo.entity;
import lombok.Data;

@Data//这里使用注解生成setter，getter，默认构造器等
public class User {
    private int id;
    private String username;
    private String name;
    private int age;
    private int balance;
}

4.MyBatis Mapper接口

package com.example.mybatisdemo.dao;

import com.example.mybatisdemo.entity.User;
import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Select;
import java.util.List;

@Mapper//注明这是一个mapper类，用于MapperScan扫描
public interface UserMapper {
    @Select("select * from user")
    List<User> queryAll();
}

5.Service层UserServeice

package com.example.mybatisdemo.service;

import com.example.mybatisdemo.dao.UserMapper;
import com.example.mybatisdemo.entity.User;
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 List<User> getAllUsers() {
        return userMapper.queryAll();
    }
}

6.Controller层UserController

package com.example.mybatisdemo.controller;


import com.example.mybatisdemo.entity.User;
import com.example.mybatisdemo.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import java.util.List;

@RequestMapping("/user")
@RestController
public class UserController {

    @Autowired
    private UserService userService;

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

7.入口类，Main方法

package com.example.mybatisdemo;

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

@SpringBootApplication
@MapperScan("com.example.mybatisdemo.dao")//扫描特定包下的所有mapper
public class MybatisdemoApplication {

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

8.SQL文件

/*
 Navicat Premium Data Transfer

 Source Server         : localhostMysql
 Source Server Type    : MySQL
 Source Server Version : 50726
 Source Host           : localhost:3306
 Source Schema         : test

 Target Server Type    : MySQL
 Target Server Version : 50726
 File Encoding         : 65001

 Date: 07/10/2019 20:01:36
*/

SET NAMES utf8mb4;
SET FOREIGN_KEY_CHECKS = 0;

-- ----------------------------
-- Table structure for user
-- ----------------------------
DROP TABLE IF EXISTS `user`;
CREATE TABLE `user`  (
  `id` int(10) UNSIGNED NOT NULL AUTO_INCREMENT,
  `username` varchar(40) CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL DEFAULT '',
  `name` varchar(20) CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL,
  `age` int(11) NOT NULL,
  `balance` int(11) UNSIGNED ZEROFILL NOT NULL,
  PRIMARY KEY (`id`) USING BTREE
) ENGINE = InnoDB AUTO_INCREMENT = 6 CHARACTER SET = utf8 COLLATE = utf8_general_ci ROW_FORMAT = Dynamic;

-- ----------------------------
-- Records of user
-- ----------------------------
INSERT INTO `user` VALUES (1, 'accout1', 'zhangsan', 20, 00000000100);
INSERT INTO `user` VALUES (2, 'accout2', 'lisi', 28, 00000000180);
INSERT INTO `user` VALUES (3, 'accout3', 'wangwu', 32, 00000000250);
INSERT INTO `user` VALUES (4, 'accout4', 'saozhu', 18, 00000000200);
INSERT INTO `user` VALUES (5, 'accout5', 'zhangtao', 22, 00000000540);

SET FOREIGN_KEY_CHECKS = 1;