标签：集成 mapper 示例 username org import com public

目录

• • 插件介绍
  • 项目结构
  • 导入pom依赖
  • 配置文件
    • 通用Mapper：
    • 分页插件：
    • 注意事项(默认是不用加的)：
  • 测试
• 脚手架项目

配置easyCode IDEA插件自动生成xml文件，开发效率简直无敌

插件介绍

通用 Mapper 是一个可以实现任意 MyBatis 通用方法的框架，项目提供了常规的增删改查操作以及 Example 相关的单表操作。通用 Mapper 是为了解决 MyBatis 使用中 90% 的单表sql编写基本操作，PageHelper则提供通用的分页查询功能，使用它们可以很方便的进行开发，可以节省开发人员大量的时间。

通用Mapper的GIT地址： https://github.com/abel533/Mapper

分页插件的GIT地址： https://github.com/pagehelper/Mybatis-PageHelper

项目结构

导入pom依赖

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xmlns="http://maven.apache.org/POM/4.0.0"
         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>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.3.0.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>

    <groupId>组织名称</groupId>
    <artifactId>工件名称</artifactId>
    <version>1.0-SNAPSHOT</version>

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

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

        <!--    通用mapper    -->
        <dependency>
            <groupId>tk.mybatis</groupId>
            <artifactId>mapper-spring-boot-starter</artifactId>
            <version>2.1.5</version>
        </dependency>
        <!--    通用分页    -->
        <dependency>
            <groupId>com.github.pagehelper</groupId>
            <artifactId>pagehelper-spring-boot-starter</artifactId>
            <version>1.3.1</version>
        </dependency>
    </dependencies>
</project>

配置文件

spring:
  datasource:
    driver-class-name: com.mysql.cj.jdbc.Driver
    username: root
    password: root
    url: jdbc:mysql://192.168.8.6:3306/znpg?useUnicode=true&characterEncoding=UTF-8&zeroDateTimeBehavior=convertToNull&allowMultiQueries=true&useSSL=false

# 通用tk.mapper配置
mapper:
  enum-as-simple-type: true
  identity: MYSQL
  mappers: tk.mybatis.mapper.common.Mapper
  not-empty: true

# 通用tk.mapper组件中mybatis配置
mybatis:
  mapper-locations: classpath*:mapper/**/*Mapper.xml
  type-aliases-package: com.ailun.test.entity
  configuration:
    map-underscore-to-camel-case: true

# 通用分页插件
pagehelper:
  helper-dialect: mysql
  params: count=countSql
  reasonable: false
  support-methods-arguments: true

# 控制台sql打印日志配置
logging:
  level:
    com:
      ailun: DEBUG

通用Mapper：

• mapper.enum-as-simple-type： 枚举按简单类型处理，如果有枚举字段则需要加上该配置才会做映射
• mapper.not-empty： 设置以后，会去判断 insert 和 update 中字符串类型 "!='' 的条件

分页插件：

• pagehelper.reasonable： 分页合理化参数，默认值为false。当该参数设置为 true 时，pageNum<=0 时会查询第一页， pageNum>pages（超过总数时），会查询最后一页。默认false 时，直接根据参数进行查询
• support-methods-arguments： 支持通过 Mapper 接口参数来传递分页参数，默认值false，分页插件会从查询方法的参数值中，自动根据上面 params 配置的字段中取值，查找到合适的值时就会自动分页

注意事项(默认是不用加的)：

由于 mybatis.mapper-locations=classpath:mapper/**/Mapper.xml配置的在java package中，而Spring Boot默认只打入java package -> *.java，所以我们需要给pom.xml文件添加如下内容

<build>
    <resources>
        <resource>
            <directory>src/main/resources</directory>
        </resource>
        <resource>
            <directory>src/main/java</directory>
            <includes>
                <include>**/*.xml</include>
            </includes>
            <filtering>true</filtering>
        </resource>
    </resources>
    <plugins>
        <plugin>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-maven-plugin</artifactId>
        </plugin>
    </plugins>
</build>

测试

1、表结构

创建一张 user表

CREATE TABLE `user` (
  `id` int(8) NOT NULL AUTO_INCREMENT COMMENT '主键自增',
  `username` varchar(50) NOT NULL COMMENT '用户名',
  `password` varchar(50) NOT NULL COMMENT '密码',
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COMMENT='用户表';

2、实体类

package com.ailun.entity;

import java.io.Serializable;


public class User implements Serializable {

    private static final long serialVersionUID = -8057591359892731452L;

    private Long id;
    private String username;
    private String password;
    
    public User() {}
    
    public User(String username, String password) {
        super();
        this.username = username;
        this.password = password;
    }
    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;
    }
}

3、持久层

package com.ailun.mapper;

import com.ailun.entity.User;
import tk.mybatis.mapper.common.Mapper; 
public interface UserMapper extends Mapper<User> { 

　　/** 
    * 根据用户名统计（假设它是一个很复杂的SQL） 
    * @param username 用户名 
    * @return 统计结果 
    */ 
　　int countByUsername(String username); 
}

4、mapper方法映射文件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.ailun.mapper.UserMapper">

  <select id="countByUsername" resultType="java.lang.Integer">
      SELECT count(1) FROM user WHERE username = #{username}
  </select>
    
</mapper>

5、启动类

package com.ailun;

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

/**
 * @author JHL
 */
@SpringBootApplication
@MapperScan(basePackages = "com.ailun.test.mapper")
public class App {

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

6.功能测试

完成数据访问层接口后，编写一个junit测试类来检验代码的正确性。

package com.ailun;

import org.junit.Test;
import org.junit.runner.RunWith;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringRunner;

import com.ailun.entity.User;
import com.ailun.mapper.UserMapper;
import com.github.pagehelper.PageHelper;
import com.github.pagehelper.PageInfo;

@RunWith(SpringRunner.class)
@SpringBootTest
public class Test {

    private final Logger logger = LoggerFactory.getLogger(this.getClass());

    @Autowired
    private UserMapper userMapper;

    @Test
    public void test() {
        try {
            final User user1 = new User("u1", "p1");
            final User user2 = new User("u1", "p2");
            final User user3 = new User("u3", "p3");
            userMapper.insertSelective(user1);
            logger.info("[user1回写主键] - [{}]", user1.getId());
            userMapper.insertSelective(user2);
            logger.info("[user2回写主键] - [{}]", user2.getId());
            userMapper.insertSelective(user3);
            logger.info("[user3回写主键] - [{}]", user3.getId());
            final int count = userMapper.countByUsername("u1");
            logger.info("[调用自己写的SQL] - [{}]", count);

            // TODO 模拟分页
            for (int i = 0; i < 20; i++) {
                userMapper.insertSelective(new User("u" + i, "p" + i));
            }
            // TODO 分页 + 排序 this.userMapper.selectAll() 这一句就是我们需要写的查询，有了这两款插件无缝切换各种数据库
            final PageInfo<User> pageInfo = PageHelper.startPage(1, 10).setOrderBy("id desc")
                    .doSelectPageInfo(() -> this.userMapper.selectAll());
            logger.info("[lambda写法] - [分页信息] - [{}]", pageInfo.toString());

            PageHelper.startPage(1, 10).setOrderBy("id desc");
            final PageInfo<User> userPageInfo = new PageInfo<>(this.userMapper.selectAll());
            logger.info("[普通写法] - [{}]", userPageInfo);
        } catch (Exception e) {
            logger.error(e.getMessage());
        }
    }
}

脚手架项目

https://github.com/lihengming/spring-boot-api-project-seed

参考：https://www.cnblogs.com/carrychan/p/9402627.html

标签：集成,mapper,示例,username,org,import,com,public
From： https://www.cnblogs.com/hhddd-1024/p/16658057.html