SpringDataJPA笔记(7)-Specification

短命女 2022-02-05 04:55 330阅读 0赞

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_github.com_wenhao_jpa-spec_blob_master_README_CN.md]

<dependency>
        <groupId>com.github.wenhao</groupId>
        <artifactId>jpa-spec</artifactId>
        <version>3.2.4</version>
    </dependency>

具体用法

<table> 
 <thead> 
  <tr> 
   <th>方法</th> 
   <th>含义</th> 
  </tr> 
 </thead> 
 <tbody> 
  <tr> 
   <td>gt/ge</td> 
   <td>greater than/greater equal ,大于/大于等于</td> 
  </tr> 
  <tr> 
   <td>lt/le</td> 
   <td>less than/less equal，小于/小于等于</td> 
  </tr> 
  <tr> 
   <td>eq/ne</td> 
   <td>equal/not equal， 等于/不等于</td> 
  </tr> 
  <tr> 
   <td>in/notIn</td> 
   <td>包含/不包含</td> 
  </tr> 
  <tr> 
   <td>like/notLike</td> 
   <td>like/notLike</td> 
  </tr> 
  <tr> 
   <td>between</td> 
   <td>between</td> 
  </tr> 
 </tbody> 
</table>

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 [GITHUB][]  
欢迎关注微信交流  
![在这里插入图片描述][70]

[https_github.com_wenhao_jpa-spec_blob_master_README_CN.md]: https://github.com/wenhao/jpa-spec/blob/master/README_CN.md
[GITHUB]: https://github.com/yingziisme/spring-boot-jpa-demo
[70]: /images/20220205/18e92c4854454423a879eba005e919b8.png