SpringBoot简单集成JPA

引入JPA的依赖

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

编写Entity

@Entity
@DynamicUpdate
@Data
public class ProductCategory {

    /** 类目id. */
    @Id
    @GeneratedValue
    private Integer categoryId;

    /** 类目名字. */
    private String categoryName;

    /** 类目编号. */
    private Integer categoryType;

    private Date createTime;

    private Date updateTime;

    public ProductCategory() {
    }
    
}

编写持久层接口

让接口继承JpaRepository接口，然后编写JPQL

public interface OrderDetailRepository extends JpaRepository<OrderDetail, String> {

    List<OrderDetail> findByOrderId(String orderId);
}

总结-注意事项

JPA的分页非常简单，只需要在普通查询方法上Pageable接口，然后再传一个PageRequest对象

public Page<OrderDTO> findList(Pageable pageable) {
    Page<OrderMaster> orderMasterPage = orderMasterRepository.findAll(pageable);

    List<OrderDTO> orderDTOList = OrderMaster2OrderDTOConverter.convert(orderMasterPage.getContent());

    return new PageImpl<>(orderDTOList, pageable, orderMasterPage.getTotalElements());
}

@GetMapping("/list")
    public ModelAndView list(@RequestParam(value = "page", defaultValue = "1") Integer page,
                             @RequestParam(value = "size", defaultValue = "10") Integer size,
                             Map<String, Object> map) {
        PageRequest request = new PageRequest(page - 1, size);
        Page<OrderDTO> orderDTOPage = orderService.findList(request);
        map.put("orderDTOPage", orderDTOPage);
        map.put("currentPage", page);
        map.put("size", size);
//        orderDTOPage.getTotalPages()
        return new ModelAndView("order/list", map);
    }

带条件分页查询-把条件传入即可