SpringDataJPA笔记(7)-Specification

网页浏览地址

https://blog.csdn.net/yingziisme/article/details/89819308

SpringDataJPA-Specification

使用Specification可以构建动态查询

原生的使用起来有点复杂，这里推介一个别人封装好的工具包

这里是github的地址

https://github.com/wenhao/jpa-spec/blob/master/README_CN.md

<!-- https://mvnrepository.com/artifact/com.github.wenhao/jpa-spec -->
<dependency>
    <groupId>com.github.wenhao</groupId>
    <artifactId>jpa-spec</artifactId>
    <version>3.2.4</version>
</dependency>

具体用法

基础查询均支持三个参数或者两个参数的用法

1. condition: 如果为 true
   (默认)，应用此条件查询。

2. property: 字段名称。

3. values: 具体查询的值，eq/ne/like 支持多个值。

不同的查询条件之间可以用and或者or来连接

具体代码使用可参考下面的实例

@Slf4j
@RestController
@RequestMapping("/chapter/seven")
public class ChapterSevenController {

    @Autowired
    private CatRepository catRepository;


    @ApiOperation(value = "and条件查询", httpMethod = "POST")
    @PostMapping("/search/cat/and")
    public List<CatEntity> searchCatAnd(@RequestBody ChapterSevenDTO chapterSevenDTO) {
        Specification<CatEntity> specification = Specifications.<CatEntity>and()
                .gt(null != chapterSevenDTO.getAge(), "age", chapterSevenDTO.getAge())
                .lt(null != chapterSevenDTO.getHeight(), "height", chapterSevenDTO.getHeight())
                .eq(null != chapterSevenDTO.getWeight(), "weight", chapterSevenDTO.getWeight()).build();
        return catRepository.findAll(specification);
    }

    @ApiOperation(value = "or条件查询", httpMethod = "POST")
    @PostMapping("/search/cat/or")
    public List<CatEntity> searchCatOr(@RequestBody ChapterSevenDTO chapterSevenDTO) {
        Specification<CatEntity> specification = Specifications.<CatEntity>or()
                .gt(null != chapterSevenDTO.getAge(), "age", chapterSevenDTO.getAge())
                .lt(null != chapterSevenDTO.getHeight(), "height", chapterSevenDTO.getHeight())
                .eq(null != chapterSevenDTO.getWeight(), "weight", chapterSevenDTO.getWeight()).build();
        return catRepository.findAll(specification);
    }

    @ApiOperation(value = "复杂条件查询", httpMethod = "POST")
    @PostMapping("/search/cat")
    public List<CatEntity> searchCat(@RequestBody ChapterSevenDTO chapterSevenDTO) {
        Specification<CatEntity> specification = Specifications.<CatEntity>or()
                .gt(null != chapterSevenDTO.getAge(), "age", chapterSevenDTO.getAge())
                .lt(null != chapterSevenDTO.getHeight(), "height", chapterSevenDTO.getHeight()).build();
        Specification<CatEntity> specification1 = Specifications.<CatEntity>and()
                .eq(null != chapterSevenDTO.getSex(), "sex", chapterSevenDTO.getSex())
                .eq(null != chapterSevenDTO.getName(), "name", chapterSevenDTO.getName()).build();
        Specification<CatEntity> specification2 = Specifications.<CatEntity>and().predicate(specification).predicate(specification1)
                .lt(null != chapterSevenDTO.getWeight(), "weight", chapterSevenDTO.getWeight()).build();

        return catRepository.findAll(specification2);
    }
}

源码参考 https://github.com/yingziisme/spring-boot-jpa-demo