mybatis-plus-AutoGenerator(自动代码生成器配置)

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使用步骤

1.引入依赖

代码如下（示例）：

        <!-- mybatisPlus 代码生成器 -->
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-generator</artifactId>
            <version>3.3.1.tmp</version>
        </dependency>
        <!-- mybatisPlus Velocity 模版引擎 -->
        <dependency>
            <groupId>org.apache.velocity</groupId>
            <artifactId>velocity-engine-core</artifactId>
            <version>2.2</version>
        </dependency>
        <!-- mybatisPlus Freemarker 模版引擎 -->
        <dependency>
            <groupId>org.freemarker</groupId>
            <artifactId>freemarker</artifactId>
            <version>2.3.29</version>
        </dependency>
        <!--mysql驱动-->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
        </dependency>
        <!-- springfox-swagger-ui -->
        <dependency>
            <groupId>io.springfox</groupId>
            <artifactId>springfox-swagger-ui</artifactId>
            <version>2.9.2</version>
        </dependency>
        <!-- springfox-swagger2 -->
        <dependency>
            <groupId>io.springfox</groupId>
            <artifactId>springfox-swagger2</artifactId>
            <version>2.9.2</version>
        </dependency>
        <!-- mybatis-plus启动器 -->
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-boot-starter</artifactId>
            <version>3.4.2</version>
        </dependency>
        <!--mybatis-plus扩展包-->
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-extension</artifactId>
            <version>3.4.2</version>
        </dependency>

2.mybaitsconfig(配置分页插件,乐观锁)

代码如下（示例）：

package com.config;

import com.baomidou.mybatisplus.annotation.DbType;
import com.baomidou.mybatisplus.extension.plugins.MybatisPlusInterceptor;
import com.baomidou.mybatisplus.extension.plugins.inner.OptimisticLockerInnerInterceptor;
import com.baomidou.mybatisplus.extension.plugins.inner.PaginationInnerInterceptor;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.transaction.annotation.EnableTransactionManagement;

@MapperScan("com.mapper")
@EnableTransactionManagement
@Configuration
public class MyBatisPlusConfig {
     


    @Bean
    public MybatisPlusInterceptor mybatisPlusInterceptor() {
     
        MybatisPlusInterceptor interceptor = new MybatisPlusInterceptor();
        // 分页插件
        interceptor.addInnerInterceptor(new PaginationInnerInterceptor(DbType.H2));
        // 注册乐观锁插件
        interceptor.addInnerInterceptor(new OptimisticLockerInnerInterceptor());
        return interceptor;
    }


}

3.MetaObjectHandler(配置自动填充处理)

代码如下（示例）：

package com.handler;

import com.baomidou.mybatisplus.core.handlers.MetaObjectHandler;
import lombok.extern.slf4j.Slf4j;
import org.apache.ibatis.reflection.MetaObject;
import org.springframework.stereotype.Component;

import java.time.LocalDateTime;


@Slf4j
@Component
public class MyMetaObjectHandler implements MetaObjectHandler {
     

    @Override
    public void insertFill(MetaObject metaObject) {
     
        log.info("start insert fill ....");
        this.strictInsertFill(metaObject, "createTime", LocalDateTime.class, LocalDateTime.now());
        this.strictInsertFill(metaObject, "updateTime", LocalDateTime.class, LocalDateTime.now());
        // update的时候使用，更新的时候强制进行填充
    }
    @Override
    public void updateFill(MetaObject metaObject) {
     
        log.info("start update fill ....");
        this.strictUpdateFill(metaObject, "updateTime", LocalDateTime.class, LocalDateTime.now());
    }
}

4.自动生成代码(AutoGenerator)

代码如下（示例）：

package com;

import com.baomidou.mybatisplus.annotation.DbType;
import com.baomidou.mybatisplus.annotation.FieldFill;
import com.baomidou.mybatisplus.annotation.IdType;
import com.baomidou.mybatisplus.generator.AutoGenerator;
import com.baomidou.mybatisplus.generator.config.DataSourceConfig;
import com.baomidou.mybatisplus.generator.config.GlobalConfig;
import com.baomidou.mybatisplus.generator.config.PackageConfig;
import com.baomidou.mybatisplus.generator.config.StrategyConfig;
import com.baomidou.mybatisplus.generator.config.po.TableFill;
import com.baomidou.mybatisplus.generator.config.rules.DateType;
import com.baomidou.mybatisplus.generator.config.rules.NamingStrategy;

import java.util.ArrayList;

public class CodeGenerator {
     
    public static void main(String[] args) {
     
        // 代码生成器
        AutoGenerator mpg = new AutoGenerator();

        // 全局配置
        GlobalConfig gc = new GlobalConfig();
        String projectPath = System.getProperty("user.dir");
        gc.setOutputDir(projectPath + "/src/main/java");
        gc.setAuthor("作者");
        gc.setOpen(false);
        // 是否覆盖
        gc.setFileOverride(false);
        // 去Service的I前缀
        gc.setServiceName("%sService");
        //雪花算法
        gc.setIdType(IdType.ASSIGN_ID);
        //实体属性 Swagger2 注解
        gc.setSwagger2(true);
        mpg.setGlobalConfig(gc);
        gc.setDateType(DateType.TIME_PACK);

        // 数据源配置
        DataSourceConfig dsc = new DataSourceConfig();
        dsc.setUrl("jdbc:mysql://localhost:3306/chen?useUnicode=true&useSSL=false&characterEncoding=utf8&serverTimezone=Asia/Shanghai");
        // dsc.setSchemaName("public");
        dsc.setDriverName("com.mysql.cj.jdbc.Driver");
        dsc.setUsername("root");
        dsc.setPassword("123");
        //数据源类型
        dsc.setDbType(DbType.MYSQL);
        mpg.setDataSource(dsc);

        // 包配置
        PackageConfig pc = new PackageConfig();
        pc.setParent("com");
        mpg.setPackageInfo(pc);


        // 策略配置
        StrategyConfig strategy = new StrategyConfig();
        strategy.setNaming(NamingStrategy.underline_to_camel);
        strategy.setColumnNaming(NamingStrategy.underline_to_camel);

        strategy.setEntityLombokModel(true);
        strategy.setRestControllerStyle(true);

        // 表名
        strategy.setInclude("user");
        // localhost:8080/hello_id_2
        strategy.setControllerMappingHyphenStyle(true);

        //逻辑删除
        strategy.setLogicDeleteFieldName("deleted");
        // 自动填充配置
        TableFill gmtCreate = new TableFill("create_time", FieldFill.INSERT);
        TableFill gmtModified = new TableFill("update_time", FieldFill.INSERT_UPDATE);
        ArrayList<TableFill> tableFills = new ArrayList<>();
        tableFills.add(gmtCreate);
        tableFills.add(gmtModified);
        strategy.setTableFillList(tableFills);

        // 乐观锁
        strategy.setVersionFieldName("version");

        mpg.setStrategy(strategy);
        mpg.execute();
    }

}

5.application.yml配置

代码如下（示例）：

# 应用名称
spring.application.name=springboot-mybatis-plus
# 应用服务 WEB 访问端口
server.port=8090

spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver
spring.datasource.url=jdbc:mysql://127.0.0.1:3306/chen?serverTimezone=UTC
spring.datasource.username=root
spring.datasource.password=123

mybatis-plus.type-aliases-package=com.entity
#日志输出(控制台打印)
mybatis-plus.configuration.log-impl=org.apache.ibatis.logging.stdout.StdOutImpl
mybatis-plus.global-config.db-config.logic-delete-value=1
mybatis-plus.global-config.db-config.logic-not-delete-value=0

6.JacksonConfig(解决雪花算法精度丢失问题)

代码如下（示例）：

package com.config;

import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.module.SimpleModule;
import com.fasterxml.jackson.databind.ser.std.ToStringSerializer;
import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Primary;
import org.springframework.http.converter.json.Jackson2ObjectMapperBuilder;

@Configuration
public class JacksonConfig {
     

    @Bean
    @Primary
    @ConditionalOnMissingBean(ObjectMapper.class)
    public ObjectMapper jacksonObjectMapper(Jackson2ObjectMapperBuilder builder) {
     
        ObjectMapper objectMapper = builder.createXmlMapper(false).build();
        // 全局配置序列化返回 JSON 处理
        SimpleModule simpleModule = new SimpleModule();
        //JSON Long ==> String
        simpleModule.addSerializer(Long.class, ToStringSerializer.instance);
        objectMapper.registerModule(simpleModule);
        return objectMapper;
    }
}

7.Oracle序列自增策略

用于解决Oracle主键是number,且太短,不能使用雪花算法时
yml配置文件添加：

#id生成策略(oracle序列)
mybatis-plus:
  global-config:
    db-config:
      id-type: input

实体类上面添加：

@KeySequence("Oracle数据里面的序列名字")
public class Vip implements Serializable {
     
    @ApiModelProperty(value = "用户编号")
    @TableId(value = "VID", type = IdType.INPUT)
    private Long vid;
	***********************************省略代码
   }

注册一个bean：

    //序列生成器
    @Bean
    public OracleKeyGenerator oracleKeyGenerator(){
     
        return new OracleKeyGenerator();
    }

补充:通过注解声明该字段不是一个数据库表里面的字段

    @TableField(exist = false)
    private  String status;

总结

一只勤奋的菜鸡