Spring启动-分页查询

Question

我想使用返回页面对象的注释@query在spring boot中编写一个查询。

所以，我的问题是：分页的最佳JPA查询类型（JPQL，NativeQuery，...）是什么？

提前谢谢你！

Answer 1

对于分页，我使用org。springframework。数据存储库。分页和排序存储库这允许存储库返回页面

存储库代码：

import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.data.repository.PagingAndSortingRepository;
import org.springframework.stereotype.Repository;

@Repository
public interface ItemRepository 
extends JpaRepository<Item, Long> , PagingAndSortingRepository<Item, Long>{
    
}

服务代码：

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.domain.Page;
import org.springframework.data.domain.Pageable;
import org.springframework.stereotype.Service;

@Service
public class ItemService {

    @Autowired
    private ItemRepository repository;

    public Page<Item> findItems(Pageable pageable){
        return repository.findAll(pageable);        
    }
        
}

控制器代码：

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.domain.Page;
import org.springframework.data.domain.Pageable;
import org.springframework.data.web.PageableDefault;
import org.springframework.web.bind.annotation.CrossOrigin;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
@RequestMapping(path="api/v1/")
@CrossOrigin(origins = "http://localhost:4200")
public class ItemController {

    @Autowired
    private ItemService service;
    
    @GetMapping("/items")
    public Page<Item> findItems(@PageableDefault(size = 5) Pageable pageable) {     
        return service.findItems(pageable);
    }
    
}

反应的身体

{
    "content": [ ... ], // contain your objects 
    "pageable": {
        "sort": {
            "sorted": false,
            "unsorted": true,
            "empty": true
        },
        "offset": 0,
        "pageNumber": 0,
        "pageSize": 5,
        "unpaged": false,
        "paged": true
    },
    "last": false,
    "totalElements": 22,
    "totalPages": 5,
    "size": 5,
    "number": 0,
    "sort": {
        "sorted": false,
        "unsorted": true,
        "empty": true
    },
    "numberOfElements": 5,
    "first": true,
    "empty": false
}

我希望这能有所帮助，祝你愉快！