SpringBoot——spring-data-jpa之分页查询

今天药忘吃喽~ 2021-10-18 14:36 467阅读 0赞

service代码

package com.youyou.address.service;
    
    import com.youyou.address.dao.ContacterDao;
    import com.youyou.address.dao.ContacterEORepo;
    import com.youyou.address.entity.ContacterEO;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.data.domain.Page;
    import org.springframework.data.domain.PageRequest;
    import org.springframework.data.domain.Pageable;
    import org.springframework.data.domain.Sort;
    import org.springframework.data.querydsl.QPageRequest;
    import org.springframework.stereotype.Service;
    import org.springframework.transaction.annotation.Transactional;
    
    import java.util.List;
    
    @Service
    @Transactional
    public class ContacterService {
    
        @Autowired
        private ContacterDao dao;
    
        @Autowired
        private ContacterEORepo contacterEORepo;
    
        public void insertOne(ContacterEO contacterEO) {
            dao.insertOne(contacterEO);
        }
    
        public List<ContacterEO> findAll() {
            return dao.findAll();
        }
    
        /**
         * 保存联系人
         *
         * @param contacterEO
         */
        public void saveOne(ContacterEO contacterEO) {
            contacterEORepo.save(contacterEO);
        }
    
        /**
         * 分页查询
         * @param page
         * @return
         */
        public Page<ContacterEO> findByPage(PageRequest page) {
            Page<ContacterEO> all = contacterEORepo.findAll(page );
            return all;
        }
    
    }

controller代码如下：

package com.youyou.address.controller;
    
    import com.youyou.address.entity.ContacterEO;
    import com.youyou.address.service.ContacterService;
    import io.swagger.annotations.Api;
    import io.swagger.annotations.ApiOperation;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.data.domain.Page;
    import org.springframework.data.domain.PageRequest;
    import org.springframework.data.domain.Sort;
    import org.springframework.web.bind.annotation.GetMapping;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RestController;
    
    import java.util.List;
    
    @Api(description = "联系人接口")
    @RestController
    @RequestMapping(value = "/contacter")
    public class ContacterController {
    
        @Autowired
        private ContacterService service;
    
        @ApiOperation(value = "新增")
        @GetMapping("/add")
        public ContacterEO add(ContacterEO contacterEO) {
            System.out.println("添加一个联系人");
    
            service.saveOne(contacterEO);
    
            return contacterEO;
        }
    
        @ApiOperation(value = "查询所有")
        @GetMapping("/findAll")
        public List<ContacterEO> findAll() {
            return service.findAll();
        }
    
        @ApiOperation(value = "分页查询")
        @GetMapping("/findByPage")
        public Page<ContacterEO> findByPage(int pageNo, int size ,Sort.Direction direction) {
            PageRequest page = PageRequest.of(pageNo, size, Sort.by(direction, "name"));
            return service.findByPage(page);
        }
    
    }

核心代码就是

PageRequest page = PageRequest.of(pageNo, size, Sort.by(direction, "name"));

pageNo：页码（从0开始）

size：每页条数

direction：排序标识，即ASC或DESC

name：需要排序的字段