Specification数据库条件模糊复杂查询java实现

系统管理员 2022-12-05 10:15 293阅读 0赞

1.Maven包

<dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-data-jpa</artifactId>
            </dependency>

2.引入

import org.springframework.data.jpa.domain.Specification;

3.Dao继承`JpaSpecificationExecutor<TTankEntity>`  
4.使用方式

@Autowired
        TankManageDao tankManage;
    
        Mapper mapper = DozerBeanMapperBuilder.buildDefault();
    
        @Override
        public Map<String, Object> findTanks(Map<String, String> tableMap) { 
            int current = Integer.valueOf(tableMap.get("current"));;
            int pageSize = Integer.valueOf(tableMap.get("pageSize"));;
            ArrayList<TTankVo> queryTanks = new ArrayList<>();
            Map<String, Object> returnMap = new HashMap<>();
            Sort sort = new Sort(Sort.Direction.ASC, "tankNo");
            Pageable pageable = new PageRequest(current-1,pageSize,sort);
            Specification<TTankEntity> specification = (root, query, cb) -> { 
                List<Predicate> predicates = new ArrayList<Predicate>();
                if (tableMap.get("tankName") != null) { 
                    String tankName = tableMap.get("tankName");
                    predicates.add(cb.like(root.get("tankName"),"%"+tankName+"%"));
                }
                if (tableMap.get("tankNo") != null) { 
                    String tankNo = tableMap.get("tankNo");
                    predicates.add(cb.like(root.get("tankNo"),"%"+tankNo+"%"));
                }
                if (tableMap.get("tankFarmid") != null) { 
                    String tankFarmid = tableMap.get("tankFarmid");
                    predicates.add(cb.like(root.get("tankFarmid"),"%"+tankFarmid+"%"));
                }
                Predicate[] pre = new Predicate[predicates.size()];
                Predicate preAnd = cb.and(predicates.toArray(pre));
                return query.where(preAnd).getRestriction();
            };
            Page<TTankEntity> tankPage = tankManage.findAll(specification,pageable);
            for (TTankEntity tank : tankPage) { 
                TTankVo tTankVo = mapper.map(tank, TTankVo.class);
                queryTanks.add(tTankVo);
            }
            returnMap.put("data", queryTanks);
            returnMap.put("total", tankManage.findAll(specification).size());
            returnMap.put("pageSize", pageSize);
            returnMap.put("current", current);
            return returnMap;
        }