吴裕雄天生自然Spring BootSpring Boot整合MyBatis

MyBatis本是apache的一个开源项目iBatis，2010年这个项目由apache software foundation迁移到了google code，并且改名为MyBatis。
    MyBatis是一个基于Java的持久层框架。MyBatis提供的持久层框架包括SQL Maps和Data Access Objects（DAO），它消除了几乎所有的JDBC代码和参数的手工设置以及结果集的检索。MyBatis使用简单的XML或注解用于配置和原始映射，将接口和Java的POJOs（Plain Old Java Objects，普通的Java对象）映射成数据库中的记录。

在Spring Boot应用中使用MyBatis框架操作数据库（基于XML的映射配置）。
具体实现步骤如下。
1．创建Spring Boot Web应用
2．修改pom.xml文件
3．设置Web应用ch6_6的上下文路径及数据源配置信息
4．创建实体类
5．创建数据访问接口
6．创建Mapper映射文件
7．创建业务层
8．创建控制器类MyUserController
9．在应用程序的主类中扫描Mapper接口
10．运行

server.port=8089

server.servlet.context-path=/ch6_2
spring.datasource.url=jdbc:mysql://localhost:3306/springbootjpa?serverTimezone=UTC&autoReconnect=true
spring.datasource.username=root
spring.datasource.password=admin
spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver
spring.jpa.database=MYSQL
spring.jpa.show-sql=true
spring.jpa.hibernate.ddl-auto=update
spring.jackson.serialization.indent-output=true 


mybatis.type-aliases-package=com.ch.ch6_6.entity
mybatis.mapperLocations=classpath:mappers/*.xml

logging.level.com.ch.ch6_6.repository=debug

<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 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <groupId>com.mybatis</groupId>
    <artifactId>SpringBootMybatis</artifactId>
    <version>0.0.1-SNAPSHOT</version>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.0.0.RELEASE</version>
        <relativePath /> <!-- lookup parent from repository -->
    </parent>

    <properties>
        <!-- 声明项目配置依赖编码格式为 utf-8 -->
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <fastjson.version>1.2.24</fastjson.version>
    </properties>

    <dependencies>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-thymeleaf</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <!-- 添加MySQL依赖 -->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
            <version>8.0.13</version><!--$NO-MVN-MAN-VER$ -->
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        
        <!-- MyBatis-Spring，Spring Boot应用整合MyBatis框架的核心依赖配置-->
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>2.1.0</version>
        </dependency>

    </dependencies>

    <build>
        <plugins>
            <plugin>
                <artifactId>maven-compiler-plugin</artifactId>
                <configuration>
                    <source>1.8</source>
                    <target>1.8</target>
                </configuration>
            </plugin>
        </plugins>
    </build>
</project>

<?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.ch.ch6_6.repository.MyUserRepository">
    <select id="findAll"  resultType="MyUser">
        select * from user 
    </select>
</mapper>

package com.ch.ch6_6.entity;

public class MyUser {
    private Integer id;
    private String username;
    private String password;

    public Integer getId() {
        return id;
    }

    public void setId(Integer 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.ch.ch6_6.repository;
import java.util.List;
import org.apache.ibatis.annotations.Mapper;
import com.ch.ch6_6.entity.MyUser;
/**
 * MyBatis的Mapper映射接口
 */
@Mapper
public interface MyUserRepository {
    public List<MyUser> findAll();
}

6．创建Mapper映射文件

<?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.ch.ch6_6.repository.MyUserRepository">
    <select id="findAll"  resultType="MyUser">
        select * from user 
    </select>
</mapper>

package com.ch.ch6_6.service;

import java.util.List;
import com.ch.ch6_6.entity.MyUser;

public interface MyUserService {
    public List<MyUser> findAll();
}

package com.ch.ch6_6.service;

import java.util.List;

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

import com.ch.ch6_6.entity.MyUser;
import com.ch.ch6_6.repository.MyUserRepository;

@Service
public class MyUserServiceImpl implements MyUserService {
    @Autowired
    private MyUserRepository myUserRepository;

    @Override
    public List<MyUser> findAll() {
        return myUserRepository.findAll();
    }
}

package com.ch.ch6_6.controller;

import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import com.ch.ch6_6.entity.MyUser;
import com.ch.ch6_6.service.MyUserService;

@RestController
public class MyUserController {
    @Autowired
    private MyUserService myUserService;

    @RequestMapping("/findAll")
    public List<MyUser> findAll() {
        return myUserService.findAll();
    }
}

package com.ch.ch6_6;

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

@SpringBootApplication
//配置扫描MyBatis接口的包路径
@MapperScan(basePackages = { "com.ch.ch6_6.repository" })
public class Ch66Application {
    public static void main(String[] args) {
        SpringApplication.run(Ch66Application.class, args);
    }
}