java进阶|MyBatis系列文章（八）代码生成器

MyBatis是支持定制化SQL,存储过程以及高级映射的优秀的持久层框架。MyBatis避免了几乎所有的JDBC代码和手动参数以及获取结果集。MyBatis可以对配置和原生Map使用简单的XML或注解，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。

<?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>2.2.6.RELEASE</version>        <relativePath/> <!-- lookup parent from repository -->    </parent>    <groupId>com.wpw</groupId>    <artifactId>mybatis-annotation-page-helper</artifactId>    <version>0.0.1-SNAPSHOT</version>    <name>mybatis-annotation-page-helper</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-web</artifactId>        </dependency>        <dependency>            <groupId>org.mybatis.spring.boot</groupId>            <artifactId>mybatis-spring-boot-starter</artifactId>            <version>2.1.2</version>        </dependency>
        <dependency>            <groupId>mysql</groupId>            <artifactId>mysql-connector-java</artifactId>            <scope>runtime</scope>        </dependency>        <dependency>            <groupId>org.projectlombok</groupId>            <artifactId>lombok</artifactId>            <optional>true</optional>        </dependency>        <dependency>            <groupId>org.springframework.boot</groupId>            <artifactId>spring-boot-starter-test</artifactId>            <scope>test</scope>            <exclusions>                <exclusion>                    <groupId>org.junit.vintage</groupId>                    <artifactId>junit-vintage-engine</artifactId>                </exclusion>            </exclusions>        </dependency>        <!-- https://mvnrepository.com/artifact/com.github.pagehelper/pagehelper-spring-boot-starter -->        <dependency>            <groupId>com.github.pagehelper</groupId>            <artifactId>pagehelper-spring-boot-starter</artifactId>            <version>1.2.12</version>        </dependency>    </dependencies>
    <build>        <plugins>            <plugin>                <groupId>org.springframework.boot</groupId>                <artifactId>spring-boot-maven-plugin</artifactId>            </plugin>            <!-- mybatis generator 自动生成代码插件 -->            <plugin>                <groupId>org.mybatis.generator</groupId>                <artifactId>mybatis-generator-maven-plugin</artifactId>                <version>1.3.2</version>                <configuration>                    <configurationFile>${basedir}/src/main/resources/generator/generatorConfig.xml</configurationFile>                    <overwrite>true</overwrite>                    <verbose>true</verbose>                </configuration>                <!-- 配置数据库链接及mybatis generator core依赖 生成mapper时使用 -->                <dependencies>                    <dependency>                        <groupId>mysql</groupId>                        <artifactId>mysql-connector-java</artifactId>                        <version>5.1.46</version>                    </dependency>                    <dependency>                        <groupId>org.mybatis.generator</groupId>                        <artifactId>mybatis-generator-core</artifactId>                        <version>1.3.2</version>                    </dependency>                </dependencies>            </plugin>        </plugins>    </build>
</project>

server:  port: 8080spring:  datasource:    url: jdbc:mysql://localhost:3306/generator?serverTimezone=UTC    username: root    password: root    driver-class-name: com.mysql.cj.jdbc.Drivermybatis:  mapper-locations: classpath:mapper/**.xml  type-aliases-package: com.wpw.mybatisannotationpagehelper.pojo  configuration:    map-underscore-to-camel-case: onpagehelper:  reasonable: true

<?xml version="1.0" encoding="UTF-8"?><!DOCTYPE generatorConfiguration        PUBLIC "-//mybatis.org//DTD MyBatis Generator Configuration 1.0//EN"        "http://mybatis.org/dtd/mybatis-generator-config_1_0.dtd"><!-- 配置生成器 --><generatorConfiguration>    <context id="DB2Tables" targetRuntime="MyBatis3">
        <commentGenerator>            <property name="suppressDate" value="true"/>            <!-- 是否去除自动生成的注释 true：是 ： false:否 -->            <property name="suppressAllComments" value="true"/>        </commentGenerator>
        <!-- 数据库链接URL，用户名、密码 -->        <jdbcConnection driverClass="com.mysql.jdbc.Driver"                        connectionURL="jdbc:mysql://localhost:3306/generator?serverTimezone=UTC"                        userId="root"                        password="root">        </jdbcConnection>
        <!-- 类型转换 -->        <javaTypeResolver>            <!-- 是否使用BigDecimals，false可自动转化以下类型(Long Integer Short等) -->            <property name="forceBigDecimals" value="false"/>        </javaTypeResolver>
        <!-- 生成模型的包名和位置-->        <javaModelGenerator targetPackage="com.wpw.mybatisannotationpagehelper.pojo" targetProject="src/main/java">            <property name="enableSubPackages" value="true"/>            <property name="trimStrings" value="true"/>        </javaModelGenerator>
        <!-- 生成映射文件的包名和位置-->        <sqlMapGenerator targetPackage="mapper" targetProject="src/main/resources">            <property name="enableSubPackages" value="true"/>        </sqlMapGenerator>
        <!-- 生成DAO的包名和位置 -->        <javaClientGenerator type="XMLMAPPER" targetPackage="com.wpw.mybatisannotationpagehelper.mapper" targetProject="src/main/java">            <property name="enableSubPackages" value="true"/>        </javaClientGenerator>
        <!-- 要生成的表 tableName是数据库中的表名或视图名 domainObjectName是实体类名-->        <table tableName="user" domainObjectName="User" enableCountByExample="false" enableUpdateByExample="false"               enableDeleteByExample="false" enableSelectByExample="false" selectByExampleQueryId="false">            <property name="useActualColumnNames" value="false"/>            <!-- 数据库表主键 -->            <generatedKey column="id" sqlStatement="Mysql" identity="true"/>        </table>    </context>
</generatorConfiguration>

create database generator;use generator;select database();create table if not exists `user`(    id       int(11) primary key auto_increment comment '用户id，自增主键',    username varchar(255) comment '用户名',    password varchar(255) comment '用户密码',    phone    varchar(255) comment '用户手机号',    address  varchar(255) comment '用户地址',    id_card  varchar(255) comment '用户身份证') engine = InnoDB  charset = utf8 COMMENT '用户表';
insert into `user`(username, password, phone, address,id_card) values ("zhangsan","123456","13507660631","zheJiang","0001");insert into `user`(username, password, phone, address,id_card) values ("lsi","123456","13507660632","zheJiang","0002");insert into `user`(username, password, phone, address,id_card) values ("wangwu","123456","13507660633","zheJiang","0003");insert into `user`(username, password, phone, address,id_card) values ("zhaoliu","123456","13507660634","zheJiang","0004");insert into `user`(username, password, phone, address,id_card) values ("sunqi","123456","13507660635","zheJiang","0005");insert into `user`(username, password, phone, address,id_card) values ("dengchao","123456","13507660636","zheJiang","0006");insert into `user`(username, password, phone, address,id_card) values ("sunli","123456","13507660637","zheJiang","0007");insert into `user`(username, password, phone, address,id_card) values ("huangxiaoming","123456","13507660638","zheJiang","0008");insert into `user`(username, password, phone, address,id_card) values ("zhaowei","123456","13507660639","zheJiang","0009");insert into `user`(username, password, phone, address,id_card) values ("zhangsan","123456","13907660631","zheJiang","0010");insert into `user`(username, password, phone, address,id_card) values ("zhangsan","123456","13907660631","zheJiang","0010");insert into `user`(username, password, phone, address,id_card) values ("zhangsan001","123456","13907660631","zheJiang","0010");insert into `user`(username, password, phone, address,id_card) values ("zhangsan002","123456","13907660632","zheJiang","0010");insert into `user`(username, password, phone, address,id_card) values ("zhangsan003","123456","13907660633","zheJiang","0010");insert into `user`(username, password, phone, address,id_card) values ("zhangsan004","123456","13907660634","zheJiang","0010");insert into `user`(username, password, phone, address,id_card) values ("zhangsan005","123456","13907660635","zheJiang","0010");insert into `user`(username, password, phone, address,id_card) values ("zhangsan006","123456","13907660636","zheJiang","0010");insert into `user`(username, password, phone, address,id_card) values ("zhangsan007","123456","13907660637","zheJiang","0010");insert into `user`(username, password, phone, address,id_card) values ("zhangsan008","123456","13907660638","zheJiang","0010");insert into `user`(username, password, phone, address,id_card) values ("zhangsan009","123456","13907660639","zheJiang","0010");insert into `user`(username, password, phone, address,id_card) values ("zhangsan010","123456","13907660100","zheJiang","0010");

package com.wpw.mybatisannotationpagehelper.controller;
import com.github.pagehelper.PageHelper;import com.wpw.mybatisannotationpagehelper.mapper.UserMapper;import com.wpw.mybatisannotationpagehelper.pojo.User;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.web.bind.annotation.PostMapping;import org.springframework.web.bind.annotation.RequestBody;import org.springframework.web.bind.annotation.RestController;
import java.util.List;
/** * @author wpw */@RestControllerpublic class UserController {    private final UserMapper userMapper;
    public UserController(UserMapper userMapper) {        this.userMapper = userMapper;    }
    @PostMapping(value = "/list-pagination")    public List<User> listPagination(@RequestBody User user) {        PageHelper.startPage(user.getPageNumber(), user.getPageSize());        return userMapper.listPagination(user);    }
    @PostMapping(value = "/list")    public List<User> listPaginationByAnnotation(@RequestBody User user) {        PageHelper.startPage(user.getPageNumber(), user.getPageSize());        return userMapper.listPaginationByAnnotation(user);    }}

package com.wpw.mybatisannotationpagehelper.mapper;
import com.wpw.mybatisannotationpagehelper.pojo.User;import org.apache.ibatis.annotations.*;import org.apache.ibatis.jdbc.SQL;import org.springframework.stereotype.Repository;
import java.util.List;
@Mapper@Repositorypublic interface UserMapper {    int deleteByPrimaryKey(Integer id);
    int insert(User record);
    int insertSelective(User record);
    User selectByPrimaryKey(Integer id);
    int updateByPrimaryKeySelective(User record);
    int updateByPrimaryKey(User record);
    List<User> listPagination(User user);
    @Results({            @Result(property = "username", column = "username"),            @Result(property = "password", column = "password"),            @Result(property = "phone", column = "phone"),            @Result(property = "idCard", column = "id_card"),            @Result(property = "address", column = "address")    })    @SelectProvider(type = UserSqlProvider.class, method = "listPaginationByAnnotation")    List<User> listPaginationByAnnotation(User user);

    class UserSqlProvider {        public String listPaginationByAnnotation(@Param("user") User user) {            SQL sql = new SQL() {                {                    SELECT("*");                    FROM("user");                    if (user.getUsername() != null && user.getUsername() != "") {                        WHERE("username like #{username}");                    }                    if (user.getPassword() != null && user.getPassword() != "") {                        WHERE("and password=#{password}");                    }                    if (user.getPhone() != null && user.getPhone() != "") {                        WHERE("and phone=#{phone}");                    }                }            };            return sql.toString();        }    }}

gitHub:https://github.com/myownmyway/mybatis-annotation-page-helper.git