Mybatis-Plus 自定义MyMetaObjectHandler填充字段无效的问题

最新推荐文章于 2025-04-22 09:45:00 发布

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最新推荐文章于 2025-04-22 09:45:00 发布

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文章标签： java

本文链接：https://blog.youkuaiyun.com/weixin_45168276/article/details/120056518

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该博客介绍了在多数据源环境下，如何配置MyMetaObjectHandler以实现字段自动填充功能。通过示例代码展示了SqlUserEntity实体类、数据源配置、MyMetaObjectHandler的实现以及MybatisPlus的连接配置。在数据插入和更新时，自动填充gmtCreate和gmtModified字段。

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多数据源的情况下 MyMetaObjectHandler无效直接上代码亲测有效在此只展示sqlserver mysql一样的道理

entity

@Data
@NoArgsConstructor
@AllArgsConstructor
@TableName("DCuser")
public class SqlUserEntity {

    @TableId(value = "ID",type = IdType.AUTO)
    private Long ID;
    private String name;
    private Integer age;
    private String school;
    private String remark;
    @TableField(value = ("gmtCreate"), fill = FieldFill.INSERT)
    private Date gmtCreate;
    @TableField(value = ("gmtModified"),fill = FieldFill.INSERT_UPDATE)
    private Date gmtModified;

}

数据源配置

@Data
@Configuration
@Component
@ConfigurationProperties(prefix = "sqlser.datasource.druid")
@MapperScan(basePackages = SqlServerDataBaseConfig.PACKAGE, sqlSessionFactoryRef = "sqlServerDataBase")
public class SqlServerDataBaseConfig {

    /**
     * dao层的包路径
     */
    static final String PACKAGE = "com.hnks.springboot_list.mapper.sqlser";

    /**
     * mapper文件的相对路径
     */
    private static final String MAPPER_LOCATION = "classpath:mapper/sqlser/*.xml";

    private String filters;
    private String url;
    private String username;
    private String password;
    private String driverClassName;
    private int initialSize;
    private int minIdle;
    private int maxActive;
    private long maxWait;
    private long timeBetweenEvictionRunsMillis;
    private long minEvictableIdleTimeMillis;
    private String validationQuery;
    private boolean testWhileIdle;
    private boolean testOnBorrow;
    private boolean testOnReturn;
    private boolean poolPreparedStatements;
    private int maxPoolPreparedStatementPerConnectionSize;


    @Bean(name = "sqlBaseConfig")
    public DataSource sqlBaseConfig() throws SQLException {
        DruidDataSource druid = new DruidDataSource();
        // 监控统计拦截的filters
        druid.setFilters(filters);

        // 配置基本属性
        druid.setDriverClassName(driverClassName);
        druid.setUsername(username);
        druid.setPassword(password);
        druid.setUrl(url);

        //初始化时建立物理连接的个数
        druid.setInitialSize(initialSize);
        //最大连接池数量
        druid.setMaxActive(maxActive);
        //最小连接池数量
        druid.setMinIdle(minIdle);
        //获取连接时最大等待时间，单位毫秒。
        druid.setMaxWait(maxWait);
        //间隔多久进行一次检测，检测需要关闭的空闲连接
        druid.setTimeBetweenEvictionRunsMillis(timeBetweenEvictionRunsMillis);
        //一个连接在池中最小生存的时间
        druid.setMinEvictableIdleTimeMillis(minEvictableIdleTimeMillis);
        //用来检测连接是否有效的sql
        druid.setValidationQuery(validationQuery);
        //建议配置为true，不影响性能，并且保证安全性。
        druid.setTestWhileIdle(testWhileIdle);
        //申请连接时执行validationQuery检测连接是否有效
        druid.setTestOnBorrow(testOnBorrow);
        druid.setTestOnReturn(testOnReturn);
        //是否缓存preparedStatement，也就是PSCache，oracle设为true，mysql设为false。分库分表较多推荐设置为false
        druid.setPoolPreparedStatements(poolPreparedStatements);
        // 打开PSCache时，指定每个连接上PSCache的大小
        druid.setMaxPoolPreparedStatementPerConnectionSize(maxPoolPreparedStatementPerConnectionSize);
        return druid;
    }

    @Bean(name = "backManager")
    public DataSourceTransactionManager backManager() throws SQLException {
        return new DataSourceTransactionManager(sqlBaseConfig());
    }



    @Bean(name = "sqlServerDataBase")
    public SqlSessionFactory sqlServerDataBaseConfig(@Qualifier("sqlBaseConfig") DataSource backDataSource) throws Exception {
        final MybatisSqlSessionFactoryBean sessionFactory = new MybatisSqlSessionFactoryBean();
        GlobalConfig globalConfig=new GlobalConfig();
        globalConfig.setMetaObjectHandler(new MyMetaObjectHandler());//生成实体并放入globalConfig
        sessionFactory.setDataSource(backDataSource);
        sessionFactory.setGlobalConfig(globalConfig);//配置自动添加时间加在配置
        sessionFactory.setMapperLocations(new PathMatchingResourcePatternResolver()
                .getResources(SqlServerDataBaseConfig.MAPPER_LOCATION));
        return sessionFactory.getObject();
    }
}

需要配置

GlobalConfig globalConfig=new GlobalConfig(); globalConfig.setMetaObjectHandler(new MyMetaObjectHandler());//生成实体并放入globalConfigsessionFactory.setGlobalConfig(globalConfig);//配置自动添加时间加在配置

配置类

@Slf4j
@Component
public class MyMetaObjectHandler implements MetaObjectHandler {
    //插入时策略
    @Override
    public void insertFill(MetaObject metaObject) {
        log.info("start insert fill ....");
        this.setFieldValByName("gmtCreate", new Date(),metaObject);
        this.setFieldValByName("gmtModified", new Date(),metaObject);
    }
    //更新策略
    @Override
    public void updateFill(MetaObject metaObject) {
        log.info("start update fill ....");
        this.setFieldValByName("gmtModified", new Date(),metaObject);
    }
}