how to configure mybatis plus?

​

<dependency>
      <groupId>com.baomidou</groupId>
      <artifactId>mybatis-plus-boot-starter</artifactId>
      <version>最新版本號</version>
  </dependency>
<dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.11</version>
        </dependency>

        <!-- https://mvnrepository.com/artifact/com.alibaba/druid -->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid-spring-boot-starter</artifactId>
            <version>1.1.10</version>
        </dependency>
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid</artifactId>
            <version>1.1.10</version>
        </dependency>

        <!-- 如果mapper.xml是放在src/main/java目錄下，需配置以下-->
<build>
  <resources>
      <resource>
          <directory>src/main/java</directory>
          <filtering>false</filtering>
          <includes>
              <include>**/mapper/*.xml</include>
          </includes>
      </resource>
  </resources>
</build>

@Configuration
//掃描dao或者是Mapper接口
@MapperScan("com.example.demo.common.orm.mapper")
public class MybatisPlusConfig {

    /**
     * mybatis-plus 分頁插件
     */

    @Bean
    public PaginationInterceptor paginationInterceptor() {
        PaginationInterceptor page = new PaginationInterceptor();
//        page.setDialectType(DBType.SQLSERVER.getDb());
        page.setDialectType(DBType.SQLSERVER2005.getDb());
        return page;
    }

    //this method is important if you want to fill common fields like create_time etc.
    @Bean
    public SqlSessionFactory sqlSessionFactory(DataSource dataSource, ResourceLoader resourceLoader, GlobalConfiguration globalConfiguration) throws Exception {
        MybatisSqlSessionFactoryBean sqlSessionFactory = new MybatisSqlSessionFactoryBean();
        sqlSessionFactory.setDataSource(dataSource);
        sqlSessionFactory.setTypeAliasesPackage("com.example.demo.common.orm.mapper");


        PathMatchingResourcePatternResolver resolver = new PathMatchingResourcePatternResolver();

        sqlSessionFactory.setMapperLocations(resolver.getResources("classpath*:com/cushmanwakefield/one/service/backend/common/orm/mapper/xml/*.xml"));
        MybatisConfiguration configuration = new MybatisConfiguration();


        sqlSessionFactory.setGlobalConfig(globalConfiguration());

        configuration.setDefaultScriptingLanguage(MybatisXMLLanguageDriver.class);
        configuration.setJdbcTypeForNull(JdbcType.NULL);
        sqlSessionFactory.setConfiguration(configuration);
        sqlSessionFactory.setPlugins(new Interceptor[]{
                paginationInterceptor(),
                new PerformanceInterceptor(),
                new OptimisticLockerInterceptor()
        });
        sqlSessionFactory.setGlobalConfig(globalConfiguration);
        return sqlSessionFactory.getObject();
    }

    @Bean
    public GlobalConfiguration globalConfiguration() {
        GlobalConfiguration conf = new GlobalConfiguration(new LogicSqlInjector());
        conf.setLogicDeleteValue("deleted");
        conf.setLogicNotDeleteValue("N");

        // conf.setIdType(2);
        // ID 策略 AUTO->`0`("數據庫ID自增") INPUT->`1`(用戶輸入ID") ID_WORKER->`2`("全局唯一ID") UUID->`3`("全局唯一ID")
        conf.setMetaObjectHandler(new MyMetaObjectHandler());

        return conf;
    }

}

public class MyMetaObjectHandler extends MetaObjectHandler{


    @Override
    public void insertFill(MetaObject metaObject) {
        super.setFieldValByName("createTime", new Date(), metaObject);


        super.setFieldValByName("deleted", "N", metaObject);
    }

    @Override
    public void updateFill(MetaObject metaObject) {
        super.setFieldValByName("updateTime", new Date(), metaObject);
    }
}
//************************************************************
public class BaseEntity<T> implements  Serializable{

    @TableId(type = IdType.ID_WORKER)
    @TableField("id")

    public Long id;


    @ApiModelProperty(readOnly = true)
    @TableLogic(delval = "Y")
    @TableField(value = "deleted", fill = FieldFill.INSERT)
    public String deleted;


    public Serializable pkVal() {
        return this.id;
    }


    @ApiModelProperty("創建時間")
    @TableField(value = "create_time", fill = FieldFill.INSERT)
    public Date createTime;


    @ApiModelProperty("修改時間")
    @TableField(value = "update_time", fill = FieldFill.UPDATE)
    public Date updateTime;

    public Long getId() {
        return id;
    }

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

    public String getDeleted() {
        return deleted;
    }

    public void setDeleted(String deleted) {
        this.deleted = deleted;
    }

    public Date getCreateTime() {
        return createTime;
    }

    public void setCreateTime(Date createTime) {
        this.createTime = createTime;
    }

    public Date getUpdateTime() {
        return updateTime;
    }

    public void setUpdateTime(Date updateTime) {
        this.updateTime = updateTime;
    }
}

public class AutoGengerate {

 public static void main(String[] args){
     AutoGenerator mpg = new AutoGenerator();

     // 全局配置
     GlobalConfig gc = new GlobalConfig();
     gc.setOutputDir("/home/fitch/workspace/test/src/main/java");
     gc.setFileOverride(true);
     gc.setActiveRecord(true);
     gc.setEnableCache(true);// XML 二級緩存
     gc.setBaseResultMap(true);// XML ResultMap
     gc.setBaseColumnList(true);// XML columList
     gc.setAuthor("fitch");
        //這個很重要  你可以在代碼中 IdWork.getId()或idWork.getIdStr()自動生產一個id, 
        //gc.setIdType(IdType.ID_WORKER_STR);
     gc.setMapperName("%sMapper");
     gc.setXmlName("%sMapper");
     gc.setServiceName("I%sService");
     gc.setServiceImplName("%sServiceImap");
     //gc.setControllerName("%sController");
     mpg.setGlobalConfig(gc);

     com.baomidou.mybatisplus.generator.config.DataSourceConfig dsc = new DataSourceConfig();
     dsc.setDbType(DbType.MYSQL);

     dsc.setDriverName("com.mysql.jdbc.Driver");
//     ?useUnicode=true&characterEncoding=UTF-8&generateSimpleParameterMetadata=true
     dsc.setUrl("jdbc:mysql://127.0.0.1:3306/test?characterEncoding=utf8");
     dsc.setUsername("root");
     dsc.setPassword("root");
     mpg.setDataSource(dsc);

     StrategyConfig strategy = new StrategyConfig();
     strategy.setNaming(NamingStrategy.underline_to_camel);

     strategy.setSuperEntityClass("com.example.demo.common.mybatis.BaseEntity");

     // 自定義實體，公共字段
     strategy.setSuperEntityColumns(new String[] { "create_time", "deleted","update_time","id" });
     mpg.setStrategy(strategy);

     // 包配置
     PackageConfig pc = new PackageConfig();
     pc.setParent("com.example.demo.common");
     pc.setModuleName("orm");
     mpg.setPackageInfo(pc);

     // 執行生成
     mpg.execute();
 }

}
//reference:http://mp.baomidou.com/#/generate-code

After running AutoGengerate , many classes are generated.

Notice:

your generated entity will be like the follow. but the type of the entities’ is long. so when the id is send to the front, it will lose precision.

TableName("home_page_banner")
public class HomePageBanner extends BaseEntity<HomePageBanner> {

    private static final long serialVersionUID = 1L;

    @TableField("banner_image")
    private String bannerImage;
    @TableField("banner_icon")
    private String bannerIcon;
    @TableField("banner_desc")
    private String bannerDesc;
    @TableField("banner_sort")
    private Integer bannerSort;
    @TableField("show_icon")
    private String showIcon;
    @TableField("show_desc")
    private String showDesc;
    @TableField("need_link")
    private String needLink;
    @TableField("link_to_module")
    private String linkToModule;
    @TableField("create_by")
    private Long createBy;
    @TableField("update_by")
    private Long updateBy;
    //.......

}

how to solve the problem?

you need to add a configuration in your web configuration file. Like this file:

@Configuration
public class WebSecurityConfig extends WebMvcConfigurerAdapter {
    .....
}

add the following. The result is when you send id, id will be transfered into the type of String.

//對long類型傳遞給前臺 lose precision
@Bean("jackson2ObjectMapperBuilderCustomizer")
public Jackson2ObjectMapperBuilderCustomizer jackson2ObjectMapperBuilderCustomizer() {
    Jackson2ObjectMapperBuilderCustomizer customizer = new Jackson2ObjectMapperBuilderCustomizer() {
        @Override
        public void customize(Jackson2ObjectMapperBuilder jacksonObjectMapperBuilder) {
            jacksonObjectMapperBuilder.serializerByType(Long.class, ToStringSerializer.instance)
                    .serializerByType(Long.TYPE, ToStringSerializer.instance);
        }
    };
    return customizer;
}