springboot~mybatis统一处理公有字段

对于实体中包含有公共字段,像create_at,create_time,update_at,update_time来说,我们没有必要在每个实体的crud操作中复制同样的代码,这样代码的味道很坏,我们应该使用mybatis的拦截器机制,将公共字段统一处理;当然mybatis-puls在实现上更加优雅,它帮我们封装了MetaObjectHandler接口,我们可以重写insertFillupdateFill来完成公共字段的统一填充,详细可看我这篇文章《springboot~MyBatisPlus中使用@TableField完成字段自动填充》。

mybatis中的实现

  • 需要实现org.apache.ibatis.plugin.Interceptor接口

  • 在intercept方法中实现业务核心逻辑

  • 在SqlSessionFactory中注册你的intercept类

  • 拦截器代码

@Intercepts({ @Signature(type = Executor.class, method = "update", args = { MappedStatement.class, Object.class }) })
public class FillCreateAndUpdateFieldInterceptor implements Interceptor {

	static final Logger logger = LoggerFactory.getLogger(FillCreateAndUpdateFieldInterceptor.class);

	@Override
	public Object intercept(Invocation invocation) throws Throwable {
		Object[] args = invocation.getArgs();
		MappedStatement ms = (MappedStatement) args[0];
		Object parameter = args[1];
		if (ms.getId().contains("insert") || ms.getId().contains("update")) {
			if (SecurityUtils.getAuthentication() != null) {

				if (parameter instanceof BaseEntity) {
					BaseEntity entity = (BaseEntity) parameter;
					if (ms.getId().contains("insert")) {
						entity.setCreateBy(SecurityUtils.getAuthentication().getName());
						entity.setCreateTime(new Date());
					}
					entity.setUpdateBy(SecurityUtils.getAuthentication().getName());
					entity.setUpdateTime(new Date());

				}
		 }
	}
}
  • 自定义SqlSessionFactory的bean
@Bean
public SqlSessionFactory sqlSessionFactory(DataSource dataSource) throws Exception {
	String typeAliasesPackage = env.getProperty("mybatis.typeAliasesPackage");
	String mapperLocations = env.getProperty("mybatis.mapperLocations");
	String configLocation = env.getProperty("mybatis.configLocation");
	typeAliasesPackage = setTypeAliasesPackage(typeAliasesPackage);
	VFS.addImplClass(SpringBootVFS.class);

	final SqlSessionFactoryBean sessionFactory = new SqlSessionFactoryBean();
	sessionFactory.setDataSource(dataSource);
	sessionFactory.setTypeAliasesPackage(typeAliasesPackage);
	sessionFactory.setMapperLocations(resolveMapperLocations(StringUtils.split(mapperLocations, ",")));
	sessionFactory.setConfigLocation(new DefaultResourceLoader().getResource(configLocation));
	SqlSessionFactory result = sessionFactory.getObject();

	// 注册自定义拦截器
	result.getConfiguration().addInterceptor(new FillCreateAndUpdateFieldInterceptor());
	return result;
}

通过上面的代码,我们就完成了公共字段的统一处理。