mybatis拦截器实现update之前根据pk字段校验数据有效性

• 数据有效性拦截器代码

/**
 * 数据有效性检查拦截器 
 * @author marke.huang
 * @date 2018/10/29 11:15
 */
@Intercepts({@Signature(
        type = Executor.class,
        method = "update",
        args = {MappedStatement.class, Object.class})})
public class DataValidityCheckInterceptor implements Interceptor {

	@Override
    public Object intercept(Invocation invocation) throws Throwable {
    	Object[] args = invocation.getArgs();
    	// 参数
        Object params = args[1];
        MapperMethod.ParamMap paramMap = (MapperMethod.ParamMap) params;
        // 实体类
        Object et = paramMap.get(Constants.ENTITY);
        // 反射获取实体类简称
        Class clazz = et.getClass().getSuperclass();
		String simpleName = clazz.getSimpleName();
		// 获取pk字段值
		BeanWrapper beanWrapper = new BeanWrapperImpl(et);
		Object pkValue = beanWrapper.getPropertyValue("pk");
		if (null != pkValue) {
			// 查询sql语句,逻辑删除
			String querySql = "SELECT COUNT(*) FROM %s WHERE DEL_FLAG = '0' AND PK = %d";
			querySql  = String.format(querySql, simpleName, pkValue);
			// spring获取mybatis查询工具类
			QueryExecutor queryExecutor = SpringContextUtils.getBean(QueryExecutor.class);
			// 执行查询sql语句
			List> list = queryExecutor.genericQuery(sql);
			// 判断数据是否存在
			if (CollectionUtils.isNotEmpty(list)) {
				Object dataCount= list.get(0).values().iterator().next();
				if (dataCount != null ) {
					String dataCountStr = String.valueOf(dataCount );
					if (!"1".equals(dataCountStr )) {
						// 抛出数据不存在异常 TODO
					}
				}
			 }         
		}
    }
}

• SpringIOC容器工具类代码

/**
 * SpringIOC容器工具类
 * 
 * @author marke.huang
 * @date 2018/7/11 9:58
 */
@Component("springContextUtil")
public final class SpringContextUtils implements ApplicationContextAware {
	private SpringContextUtils() {
    }
    
	/**
     * Spring上下文对象
     */
    private static ApplicationContext applicationContext;
	
	@Override
    public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
        SpringContextUtils.applicationContext = applicationContext;
    }

	/**
     * 按类型获取托管对象 
     *
     * @param clazz 类型
     * @return T 对象
     * @author marke.huang
     * @date 2018/7/12 9:41
     */
    public static  T getBean(Class clazz) {
        return SpringContextUtils.applicationContext.getBean(clazz);
    }
}

• MyBatis 查询工具类代码

/**
 * MyBatis 查询工具类
 * @author jiangming.huang
 * @date 2018/10/31 0031 下午 2:05
 */
@Service
@Slf4j
public class QueryExecutor {
	@Autowired
    private SqlSessionFactory sessionFactory;

	/**
     * 执行SQL
     *
     * @param sql
     * @return
     */
    public List> genericQuery(String sql) {
        if (StringUtils.isEmpty(sql) || !(sql.toLowerCase().trim().startsWith("select") || sql.toLowerCase().trim().startsWith("call"))) {
            return null;
        }
        SqlSession sqlSession = sessionFactory.openSession();
        try {
            GenericQueryMapper query = sqlSession.getMapper(GenericQueryMapper.class);
            return query.query(sql);
        } catch (Exception e) {
            log.error("执行SQL查询时发生错误.sql == " + sql, e);
        } finally {
            sqlSession.close();
        }
        return null;
    }
	
	/**
     * 执行SQL， SQL 参数的格式参照 MyBatis, 即用 #{param_name}
     *
     * @param sql
     * @param params
     * @return
     */
    public List> genericQuery(String sql, Object params) {
        if (StringUtils.isEmpty(sql) || !(sql.toLowerCase().trim().startsWith("select") || sql.toLowerCase().trim().startsWith("call"))) {
            return null;
        }
        SqlSession sqlSession = sessionFactory.openSession();
        try {
            GenericQueryMapper query = sqlSession.getMapper(GenericQueryMapper.class);
            return query.queryWithParams(sql, params);
        } catch (Exception e) {
            log.error("执行SQL查询时发生错误.sql == " + sql, e);
        } finally {
            sqlSession.close();
        }
        return null;
    }
}

• MyBatis动态执行sql语句Mapper代码

/**
 * 类功能描述:MyBatis动态执行sql语句
 *
 * @author marke.huang
 * @date 2018/10/31 0031 下午 2:05
 */
public interface GenericQueryMapper {

    /**
     * 带条件查询
     *
     * @param sql
     * @param params
     * @return
     */
    @Select("${sql}")
    List> queryWithParams(@Param("sql") String sql, @Param("params") Object params);

    /**
     * 不带条件查询
     *
     * @param sql
     * @return
     */
    @Select("${sql}")
    List> query(@Param("sql") String sql);
}