springboot 入门

新建springboot项目

2.
3. pom.xml

<?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>2.7.10</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.example</groupId>
    <artifactId>demo7</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>demo7</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-jdbc</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <!-- Druid 数据源 -->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid-spring-boot-starter</artifactId>
            <version>1.1.10</version>
        </dependency>
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>2.3.0</version>
        </dependency>

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.46</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

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

</project>

4. 配置文件 application.properties

mybatis.config-location=classpath:mybatis/mybatis-config.xml
mybatis.mapper-locations=classpath:mybatis/mapper/*.xml
mybatis.type-aliases-package=com.example.demo7.model

spring.datasource.url=jdbc:mysql://localhost:3306/springboot?serverTimezone=UTC&useUnicode=true&characterEncoding=utf-8&useSSL=true
spring.datasource.username=root
spring.datasource.password=root
#spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver
spring.datasource.driver-class-name=com.mysql.jdbc.Driver

5. 项目结构
   
6. mybatis-config.xml

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration PUBLIC "-//mybatis.org//DTD Config 3.0//EN" "http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
    <typeAliases>
        <typeAlias alias="Integer" type="java.lang.Integer" />
        <typeAlias alias="Long" type="java.lang.Long" />
        <typeAlias alias="HashMap" type="java.util.HashMap" />
        <typeAlias alias="LinkedHashMap" type="java.util.LinkedHashMap" />
        <typeAlias alias="ArrayList" type="java.util.ArrayList" />
        <typeAlias alias="LinkedList" type="java.util.LinkedList" />
    </typeAliases>
</configuration>

7. 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.demo7.mapper.UserMapper" >
    <resultMap id="BaseResultMap" type="com.example.demo7.model.User" >
        <id column="id" property="id" jdbcType="BIGINT" />
        <result column="userName" property="userName" jdbcType="VARCHAR" />
        <result column="passWord" property="passWord" jdbcType="VARCHAR" />
        <result column="user_sex" property="userSex" javaType="com.example.demo7.enums.UserSexEnum"/>
        <result column="nick_name" property="nickName" jdbcType="VARCHAR" />
    </resultMap>

    <sql id="Base_Column_List" >
        id, userName, passWord, user_sex, nick_name
    </sql>

    <select id="getAll" resultMap="BaseResultMap"  >
        SELECT
        <include refid="Base_Column_List" />
        FROM users
    </select>

    <select id="getOne" parameterType="java.lang.Long" resultMap="BaseResultMap" >
        SELECT
        <include refid="Base_Column_List" />
        FROM users
        WHERE id = #{id}
    </select>

    <insert id="insert" parameterType="com.example.demo7.model.User" >
        INSERT INTO
            users
            (userName,passWord,user_sex)
        VALUES
            (#{userName}, #{passWord}, #{userSex})
    </insert>

    <update id="update" parameterType="com.example.demo7.model.User" >
        UPDATE
        users
        SET
        <if test="userName != null">userName = #{userName},</if>
        <if test="passWord != null">passWord = #{passWord},</if>
        nick_name = #{nickName}
        WHERE
        id = #{id}
    </update>

    <delete id="delete" parameterType="java.lang.Long" >
        DELETE FROM
            users
        WHERE
            id =#{id}
    </delete>

</mapper>

8. demo7-model-User.java

package com.example.demo7.model;

import com.example.demo7.enums.UserSexEnum;

import java.io.Serializable;

public class User implements Serializable {
    private static final long serialVersionUID = 1L;
    private Long id;
    private String userName;
    private String passWord;
    private UserSexEnum userSex;
    private String nickName;

    public User() {
        super();
    }

    public User(String userName, String passWord, UserSexEnum userSex) {
        super();
        this.passWord = passWord;
        this.userName = userName;
        this.userSex = userSex;
    }

    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;
    }

    public UserSexEnum getUserSex() {
        return userSex;
    }

    public void setUserSex(UserSexEnum userSex) {
        this.userSex = userSex;
    }

    public String getNickName() {
        return nickName;
    }

    public void setNickName(String nickName) {
        this.nickName = nickName;
    }

    @Override
    public String toString() {
        // TODO Auto-generated method stub
        return "userName " + this.userName + ", pasword " + this.passWord + "sex " + userSex.name();
    }
}

9. demo7-mapper-UserMapper.java

package com.example.demo7.mapper;

import com.example.demo7.model.User;
import java.util.List;
public interface UserMapper {
    List<User> getAll();

    User getOne(Long id);

    void insert(User user);

    void update(User user);

    void delete(Long id);
}

10. demo7-web-UserController.java

package com.example.demo7.web;

import java.util.List;

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.RestController;

import com.example.demo7.model.User;
import com.example.demo7.mapper.UserMapper;

@RestController
public class UserController {
    @Autowired(required = false)
    private UserMapper userMapper;

    @RequestMapping("/he")
    public String hello(){
        return "he";
    }
    @RequestMapping("/getUsers")
    public List<User> getUsers() {
        List<User> users=userMapper.getAll();
        return users;
    }

    @RequestMapping("/getUser")
    public User getUser(Long id) {
        User user=userMapper.getOne(id);
        return user;
    }

    @RequestMapping("/add")
    public void save(User user) {
        userMapper.insert(user);
    }

    @RequestMapping(value="update")
    public void update(User user) {
        userMapper.update(user);
    }

    @RequestMapping(value="/delete/{id}")
    public void delete(@PathVariable("id") Long id) {
        userMapper.delete(id);
    }
}

11. demo7-enums-UserSexEnum.java

package com.example.demo7.enums;

public enum UserSexEnum {
    MAN, WOMAN
}

12. Demo7Application

package com.example.demo7;

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

@SpringBootApplication
@MapperScan("com.example.demo7.mapper")
public class Demo7Application {

    public static void main(String[] args) {
        SpringApplication.run(Demo7Application.class, args);
    }

}

13. resources-mybatis-mapper-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.demo7.mapper.UserMapper" >
    <resultMap id="BaseResultMap" type="com.example.demo7.model.User" >
        <id column="id" property="id" jdbcType="BIGINT" />
        <result column="userName" property="userName" jdbcType="VARCHAR" />
        <result column="passWord" property="passWord" jdbcType="VARCHAR" />
        <result column="user_sex" property="userSex" javaType="com.example.demo7.enums.UserSexEnum"/>
        <result column="nick_name" property="nickName" jdbcType="VARCHAR" />
    </resultMap>

    <sql id="Base_Column_List" >
        id, userName, passWord, user_sex, nick_name
    </sql>

    <select id="getAll" resultMap="BaseResultMap"  >
        SELECT
        <include refid="Base_Column_List" />
        FROM users
    </select>

    <select id="getOne" parameterType="java.lang.Long" resultMap="BaseResultMap" >
        SELECT
        <include refid="Base_Column_List" />
        FROM users
        WHERE id = #{id}
    </select>

    <insert id="insert" parameterType="com.example.demo7.model.User" >
        INSERT INTO
            users
            (userName,passWord,user_sex)
        VALUES
            (#{userName}, #{passWord}, #{userSex})
    </insert>

    <update id="update" parameterType="com.example.demo7.model.User" >
        UPDATE
        users
        SET
        <if test="userName != null">userName = #{userName},</if>
        <if test="passWord != null">passWord = #{passWord},</if>
        nick_name = #{nickName}
        WHERE
        id = #{id}
    </update>

    <delete id="delete" parameterType="java.lang.Long" >
        DELETE FROM
            users
        WHERE
            id =#{id}
    </delete>

</mapper>

14. 运行项目
    
15. 请求接口测试效果

• http://localhost:8080/he
  返回 “he”
• http://localhost:8080/getUsers

[{"id":1,"userName":"aa1","passWord":"a123456","userSex":"MAN","nickName":"pt"}]

• http://localhost:8080/getUser

{
"id": 1,
"userName": "aa1",
"passWord": "a123456",
"userSex": "MAN",
"nickName": "pt"
}

• http://localhost:8080/add

请求参数：
userName:bb1
passWord:b123456
userSex:WOMAN
nickName:je
返回数据：

示例代码