java——mybatis随笔

教程：https://www.cnblogs.com/xiaobaibailongma/p/17019484.html

 

 

 

 

本地示例：https://www.cnblogs.com/xiaobaibailongma/p/17019676.html

 

 

 

 

 

 

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gitee：示例

 

 

 

 

 

 

 

 

 

spring_boot/pom.xml

 

配置文件：https://gitee.com/xiaobailongbailongma/springboot/blob/master/spring_boot/pom.xml

 

 

 

 

 

 

 

spring_boot/src/main/resources/application.properties

 

配置文件：https://gitee.com/xiaobailongbailongma/springboot/blob/master/spring_boot/src/main/resources/application.properties

 

 

 

 

 

 

 

 

 

 

spring_boot/src/main/resources/mappers/MyUserMapper.xml

 

配置文件：https://gitee.com/xiaobailongbailongma/springboot/blob/master/spring_boot/src/main/resources/mappers/MyUserMapper.xml

 

 

 

 

 

 

 

 

spring_boot/src/main/java/org/example/mapper/UserMapper.java

 

配置文件：https://gitee.com/xiaobailongbailongma/springboot/blob/master/spring_boot/src/main/java/org/example/mapper/UserMapper.java

 

 

 

 

 

 

 

 

 

 

 

 spring_boot/src/main/java/org/example/service/UserService.java

 

 配置文件：https://gitee.com/xiaobailongbailongma/springboot/blob/master/spring_boot/src/main/java/org/example/service/UserService.java

 

 

 

 

 

 

spring_boot/src/main/java/org/example/service/Impl/UserServiceImpl.java

 

配置文件：https://gitee.com/xiaobailongbailongma/springboot/blob/master/spring_boot/src/main/java/org/example/service/Impl/UserServiceImpl.java

 

 

 

 

 

 

 

 

 

 

 

 

spring_boot/src/main/java/org/example/controller/mybatis/MyUserController.java

 

配置文件：https://gitee.com/xiaobailongbailongma/springboot/blob/master/spring_boot/src/main/java/org/example/controller/mybatis/MyUserController.java

 

 

 

 

 

 

 

 

 

 

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总体步骤按照如下：

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

第二步——修改pom文件：

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<?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 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>org.example</groupId>
    <artifactId>spring_boot</artifactId>
    <version>1.0-SNAPSHOT</version>

    <properties>
        <maven.compiler.source>8</maven.compiler.source>
        <maven.compiler.target>8</maven.compiler.target>
    </properties>


    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.4.5</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>

    <dependencies>
        <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>2.1.1</version>
        </dependency>

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

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
        </dependency>

    </dependencies>


</project>
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也可以按照教程上面的写，格式如下：

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<?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 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>org.example</groupId>
    <artifactId>spring_boot</artifactId>
    <version>1.0-SNAPSHOT</version>

    <properties>
        <maven.compiler.source>8</maven.compiler.source>
        <maven.compiler.target>8</maven.compiler.target>
    </properties>


    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.4.5</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>

    <dependencies>
        <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>2.1.1</version>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
        </dependency>

    </dependencies>


</project>
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第二步——配置数据源：

 

application.properties：

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spring.main.banner-mode = off
test.environment = read config by environment
obj.sname=chenheng
obj.sage=88

#设定日志的默认级别为info
logging.level.root=info

##设定org包下的日志级别为warn
#logging.level.org=warn

##设定com.ch.ch4_1包下的日志级别为debug
#logging.level.com.ch.ch4_1=debug

logging.file=c:/log/my.log
logging.pattern.console=%level %date{yyyy-MM-dd HH:mm:ss:SSS} %logger{50}.%M %L :%m%n
logging.pattern.file=%level %date{ISO8601} %logger{50}.%M %L :%m%n


###
##数据源信息配置
###
#数据库地址
spring.datasource.url=jdbc:mysql://localhost:3306/mysql8?characterEncoding=utf8

#数据库用户名
spring.datasource.username=root

#数据库密码
spring.datasource.password=123456

#数据库驱动  spring.datasource.driver-class-name=com.mysql.jdbc.Driver
spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver

#告诉系统在哪里去找mapper.xml文件（映射文件）
mybatis.mapperLocations=classpath:mappers/*.xml
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第四步——创建实体类：

 

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package org.example.entity;

public class MyUser
{
    private int id;
    private String name;
    private int age;

    
    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    
    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }
    
    

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }
}
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第五步——创建数据库访问接口：

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package org.example.mapper;

import org.example.entity.MyUser;
import org.apache.ibatis.annotations.Mapper;

import java.util.List;

@Mapper
public interface UserMapper
{

    public List<MyUser> findAll();

}
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第六步——创建mapper映射文件：

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<?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="org.example.mapper.UserMapper">
    <select id="findAll" resultType="org.example.entity.MyUser">
        select * from users
    </select>
</mapper>
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第七步——创建业务层：

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package org.example.service;


import org.example.entity.MyUser;

import java.util.List;

public interface UserService
{
    List<MyUser> findAll();
    
    
}
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package org.example.service.Impl;


import org.example.entity.MyUser;
import org.example.mapper.UserMapper;
import org.example.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.List;

@Service
public class UserServiceImpl implements UserService
{
    @Autowired
    UserMapper userMapper;

    @Override
    public List<MyUser> findAll()
    {

        return userMapper.findAll();
    }

}
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第八步——创建控制器类：

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package org.example.controller;

import java.util.List;
import org.example.entity.MyUser;
import org.example.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class MyUserController
{

    @Autowired
    private UserService userService;

    @GetMapping(value = "/1")
    public List<MyUser> home1()
    {
        // 查询所有网站
        List<MyUser> users = userService.findAll();

        for (MyUser user : users)
        {
            System.out.println(user.getId()+"  "+user.getName()+"  "+user.getName());
        }
        
        

        return users;
    }
    
    
}
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第九步——运行主类：

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package org.example;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;


@SpringBootApplication
public class helloWorldApplication
{

    public static void main(String[] args)
    {

        SpringApplication.run(helloWorldApplication.class, args);

    }
}
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第十步——访问：

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

数据库表信息：

 

 

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CREATE TABLE `users` (

  `id` int NOT NULL,
  `name` varchar(255) DEFAULT NULL,
  `age` int DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb3;
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posted @ 2023-09-24 11:54  小白龙白龙马  阅读(6)  评论(0)  编辑  收藏  举报