基于SpringBoot框架MyBatis快速入门搭建运行一个访问数据源的应用程序

专业
语言(MyBatis)
发布日期:   2021-11-05
更新日期:   2022-06-16
文章字数:   1.5k
阅读时长:   8 分
阅读次数:  

一、环境配置

  • Java环境：1.8版本
  • 开发工具： Intellij IDEA

二 简单应用

  • 1.创建项目
    IDEA中创建maven
  • 2.填写项目名称和项目存放路径，点击Finish:
    IDEA中写maven的项目名称和路径
  • 3.进入项目界面如下(因为本人已经建立好了，所以显示有对应文件)：
    初始化项目文件

三、熟悉的HelloWorld

  • 先在com.springboot下新建一个Package，命名为controller，再在controller下创建一个HelloWorldController类，如下：
    package com.springboot.controller;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
/**
 * @author shajiu
 * @date 2021/11/5 13:48
 */
@RestController
public class HelloWorldController {
    @GetMapping("/hello")
    public String sayHelloWorld() {
        System.out.println("测试段!!!");
        return "HelloWorld";
    }
}
  • 注释@RequestMapping(value = “/hello”)是指定映射的URL，@RestController是将它标注的类中的所有方法返回的json格式的数据转化成视图view。
  • 运行程序，在DemoApplication.java文件中，运行程序：
    package com.springboot;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
/**
 * @author shajiu
 * @date 2021/11/5 13:49
 */
@SpringBootApplication
@MapperScan("com.springboot.mapper")
public class DemoApplication {
    public static void main(String[] args) {
        SpringApplication.run(DemoApplication.class, args);
    }
}
    运行的结果

四、使用mybatis连接mysql数据库完成数据访问。

话不多说直接上代码，具体解释其对应代码中描述。 代码框架结构如下：
Demo代码的框架结构图

1、在pom.xml文件中添加依赖，直接用如下替换之前的即可：
<?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>2.3.9.RELEASE</version>
        <relativePath/>
        <!-- lookup parent from repository -->
    </parent>
    <groupId>com.rs.cloud.business</groupId>
    <artifactId>cache</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>cache</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</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <!--druid-->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid-spring-boot-starter</artifactId>
            <version>1.1.17</version>
        </dependency>
        <!--aop-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-aop</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-jdbc</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>1.3.2</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-jetty</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis-spring</artifactId>
            <version>2.0.4</version>
        </dependency>
    </dependencies>
    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>
</project>
2、修改后缀名为application.yml，直接用如下替换即可
server:
  port: 1234
  servlet:
    context-path: /cn
spring:
  datasource:
    url: jdbc:oracle:thin:@192.168.168.105:1521:ZLORANEW
    username: devnew
    password: devpass
    driver-class-name: oracle.jdbc.OracleDriver
mybatis:
  mapper-locations:
    - classpath*:mapper/*.xml
3、数据访问层
  • 3.1. UserPO类 
    package com.springboot.po;
import java.io.Serializable;
/**
 * @author shajiu
 * @date 2021/11/5 13:34
 */
public class UserPO implements Serializable {
    /**
     * 用户ID
     */
    private int id;
    /**
     * 用户名
     */
    private String username;
    /**
     * 用户密码
     */
    private String password;
    /**
     * 年龄
     */
    private int age;
    /**
     * 性别
     */
    private String sex;
    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;
    }
    public int getAge() {
        return age;
    }
    public void setAge(int age) {
        this.age = age;
    }
    public String getSex() {
        return sex;
    }
    public void setSex(String sex) {
        this.sex = sex;
    }
}
  • 3.2. User类implements了一个Serializable类，该类的作用是序列化。
  • 3.2.1. UserMapper接口:
    package com.springboot.mapper;
import org.apache.ibatis.annotations.Mapper;
import org.springframework.stereotype.Repository;
/**
 * @author shajiu
 * @date 2021/11/5 13:35
 */
@Repository
public interface UserMapper {
    int getAgeByUsername(String username);
}
  • 3.2.2. UserMapper.xml配置文件： 
    <?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的namespace指定了该xml文件指向的Mapper接口，里面的sql语句接受传来的username数据进行数据访问。-->
<!--        语句的id="getAgeByUsername"则是对应mapper接口中的方法，resultType="int"指定本次数据访问的数据返回类型。-->
<mapper namespace="com.springboot.mapper.UserMapper">
    <resultMap id="ResultMap" type="com.springboot.po.UserPO">
        <result column="ID" jdbcType="VARCHAR" property="id"/>
        <result column="USERNAME" jdbcType="VARCHAR" property="username"/>
        <result column="PASSWORD" jdbcType="VARCHAR" property="password" />
        <result column="AGE" jdbcType="VARCHAR" property="age"/>
        <result column="SEX" jdbcType="VARCHAR" property="sex"/>
    </resultMap>
    <sql id="Base_Column_List">
        ID,USERNAME,PASSWORD,AGE,SEX
    </sql>
    <select id="getAgeByUsername" resultType="int">
        SELECT age FROM spring_boot_demo
    </select>
<!--    <select id="getNameByUsername" parameterType="com.springboot.po.UserPO" resultMap="ResultMap">-->
<!--        SELECT * from ${UserPO.username}-->
<!--    </select>-->
</mapper>
4、业务逻辑层
  • 4.1、UserService类 
     package com.springboot.service;
import javax.annotation.Resource;
 /**
  * @author shajiu
  * @date 2021/11/5 13:39
  */
 @Resource
 public interface UserService {
     int getAgeByUsername(String username);
 }
  • 4.2、UserServiceImpl类
    package com.springboot.service.impl;
import com.springboot.mapper.UserMapper;
import com.springboot.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
/**
 * @author shajiu
 * @date 2021/11/5 13:47
 */
@Service
public class UserServiceImpl implements UserService {
    @Autowired
    //通过@Autowired注解获得自动注入的userMapper实现类，在重写的方法中进行调用，获得数据。
    UserMapper userMapper;
    @Override
    public int getAgeByUsername(String username) {
        return userMapper.getAgeByUsername(username);
    }
}

5、页面展示层

  • UserController类
    package com.springboot.controller;
import com.springboot.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
/**
 * @author shajiu
 * @date 2021/11/5 13:48
 */
@RestController
public class UserController {
    @Autowired
    UserService userService;
    @RequestMapping("/user/age")
    public int getAgeOfUser(){
        return userService.getAgeByUsername("springbootdemo");
    }
}

6、运行程序

package com.springboot;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
/**
 * @author shajiu
 * @date 2021/11/5 13:49
 */
@SpringBootApplication
@MapperScan("com.springboot.mapper")
public class DemoApplication {
    public static void main(String[] args) {
        SpringApplication.run(DemoApplication.class, args);
    }
}

7、测试数据如下，spring_boot_demo：

spring_boot_demo

8、若需源码，请点击这里下载即可直接使用SpringBoot

文章作者: 沙九
文章链接: http://shajiu.com/2021/11/05/ji-yu-springboot-kuang-jia-mybatis-kuai-su-ru-men-da-jian-yun-xing-yi-ge-fang-wen-shu-ju-yuan-de-ying-yong-cheng-xu/
版权声明: 本博客所有文章除特別声明外，均采用 CC BY 4.0 许可协议。转载请注明来源 沙九 !
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