baomidou.mybatisplus对查询结果进行分页

 

在springboot中，要使用baomidou.mybatisplus对查询结果进行分页的逻辑过程

maven依赖

	com.baomidou
	mybatis-plus-boot-starter
	3.2.0

config代码

import org.mybatis.spring.annotation.MapperScan;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

import com.baomidou.mybatisplus.extension.plugins.PaginationInterceptor;

/**
 * MybatisPlusConfigurer
 * 

 * Description
 * 
 * Creation Time: 2019/11/25 16:37.
 *
 */
@Configuration
public class MybatisPlusConfigurer {
    @Bean
    public PaginationInterceptor paginationInterceptor() {
        return new PaginationInterceptor();
    }
}

SQL映射XML

	SELECT  a.app_code || ',' || a.module  || ',' || a.dimension as querytype ,b.parameter
   from (SELECT * FROM public.g_a_indicator_relation
	
	WHERE
	app_code = #{appCode}
	) a
   INNER JOIN public.g_a_indicators b
   ON a.indicator_id=b.indicator_id


  
	SELECT
	warn.alert_time,
	info.device_name,
	rule.indicator_name,
	rule.indicator_rule_name,
	'已恢复' as alert_status,
	warn.ensure_time,
	round(date_part('epoch', (warn.ensure_time-warn.alert_time))::NUMERIC/3600,2) as lasting_time
	FROM
	"public".g_d_w warn
	LEFT JOIN "public".g_d_w_rule rule ON warn.indicator_id = rule.indicator_id
	LEFT JOIN "public".g_a_detail_info info ON warn.device_code = info.device_code
	
		
			
				warn.alert_time >= #{timeSlots.startTime} and
			
			
				warn.alert_time  <= #{timeSlots.endTime} and
			
			
				info.device_code in
				
						#{item,jdbcType=BIGINT}
				
				and
			
			
				rule.indicator_id in
				
					#{item,jdbcType=INTEGER}
				
				and
			
			
				rule.indicator_rule_name in
				
					#{item}
				
				and
			
		
	
	order by alert_time desc


	select * from tb_brand where `name` like concat('%',#{key},'%')

service层

import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import com.a.b.c.entity.alarm.GDWarnConfig;
import com.a.b.c.entity.alarm.GAStatistics;

import java.util.Date;
import java.util.List;
import java.util.Map;


public interface GAQueryService {
    /**
     * get alert result.
     *
     * params timeSlots:[startTime:Date,endTime:Date]
     * params pageNum:
     * params pageSize:
     *
     * @return Page
     */
    Page getAlertResult(Map timeSlots, List deviceCodeList, List indicatorIdList, List indicatorRuleNameList, String status, int pageNum, int pageSize);
    
}

mapper层

若不想在service层，写分页的处理，可以直接在mapper层引入！详情可见https://blog.csdn.net/Milan__Kundera/article/details/97615996

本案例是在service层，进行自定义分页

​​​​​​​List getAlertResult(Map params);

impl层

Collections.sort(result, new Comparator() {
		@Override
		public int compare(GAStatistics o1, GAStatistics o2) {
			long time1 = o1.getAlertTime().getTime();
			long time2 = o2.getAlertTime().getTime();
			long subtract = time1 -time2;
			return subtract == 0?0:subtract > 0?-1:1;
		}
	});
	if (pageSize == -1){
		GAStatisticsPage.setRecords(result);
	}else {
		GAStatisticsPage.setRecords(getPagingDate(result,pageNum,pageSize));
	}

}else if (Objects.equals("1",status)){
	Map params = new HashMap<>();
	GAStatisticsPage.setCurrent(pageNum);
	GAStatisticsPage.setSize(pageSize);
	params.put("page",GAStatisticsPage);
	params.put("timeSlots",timeSlots);
	params.put("deviceCode",deviceCodeList);
	params.put("indicatorId",indicatorIdList);
	params.put("indicatorRuleName",indicatorRuleNameList);
	List alertResultList = gemAlarmQueryMapper.getAlertResult(params);
	/*alertResultList = transformData(alertResultList);*/
	GAStatisticsPage.setRecords(alertResultList);
}
return GAStatisticsPage;

直接把参数封装在map中，进而送到mapper映射的SQL进行分页查询！

controller层

Page alertResultPage = gemAlarmQueryService.getAlertResult(timeSlots, null, null, null, "0", 12, -1);
List alertResultList = alertResultPage.getRecords();
//根据级别、时间排序
Collections.sort(alertResultList, new Comparator() {
	@Override
	public int compare(GAStatistics o1, GAStatistics o2) {
		try {
			String indicatorRuleName1 = o1.getIndicatorRuleName();
			String indicatorRuleName2 = o2.getIndicatorRuleName();
			long alertTime1 = o1.getAlertTime().getTime();
			long alertTime2 = o2.getAlertTime().getTime();
			if (!Objects.equals(indicatorRuleName1,indicatorRuleName2)){
				int ascSubtract = indicatorRuleName1.compareTo(indicatorRuleName2);
				return ascSubtract>0?1:-1;
			}else {
				long timeSubtract = alertTime1 - alertTime2;
				return timeSubtract>0?-1:1;
			}
		}catch (Exception e){
			logger.error(e.getMessage());
			return 0;
		}
	}
});