SpringBoot引入分页插件PageHelper

官网

https://pagehelper.github.io/docs/howtouse/

引入步骤 第1步：引入依赖 <!--分页插件--> <dependency> <groupId>com.github.pagehelper</groupId> <artifactId>pagehelper</artifactId> <version>5.3.2</version> </dependency>

第2步：配置拦截器插件 @Configuration public class AppConfig { @Bean public PageInterceptor pageInterceptor() { PageInterceptor pageInterceptor = new PageInterceptor(); Properties properties = new Properties(); // 分页合理化，true开启，如果分页参数不合理会自动修正。默认false不启用 properties.setProperty("reasonable", "true"); pageInterceptor.setProperties(properties); return pageInterceptor; } }

[Ref] 整合PageHelper实现分页

第3步：插件的使用 前提： 业务提供 查询所有学生的方法 // com.zhangziwa.practisesvr.mapper.UserMapper#listStudents <select id="listStudents" resultMap="StudentMap"> SELECT * FROM students </select> // com.zhangziwa.practisesvr.mapper.UserMapper List<Student> listStudents();

不使用分页插件 会查出全部 List<Student> students = userMapper.listStudents();

方式1：PageInfo public List<Student> listStudents2(Integer pageNum, Integer PageSize) { PageHelper.startPage(1, 10, true); PageHelper.orderBy("age asc"); List<Student> students = userMapper.listStudents(); PageInfo<Student> studentPageInfo = PageInfo.of(students); return students; }

方式2：Page public List<Student> listStudents2(Integer pageNum, Integer PageSize) { PageHelper.startPage(1, 10, true); PageHelper.orderBy("age asc"); Page<Student> students = (Page<Student>) userMapper.listStudents(); return students; }

方式3：多数据源聚合时的手工分页 public List<Student> listStudents3(Integer pageNum, Integer pageSize) { // 模拟数据聚合 List<Student> students3 = new ArrayList<>(); List<Student> students1 = userMapper.listStudents(); List<Student> students2 = userMapper.listStudents(); students3.addAll(students1); students3.addAll(students2); Page<Student> studentsPage = PageHeaderUtils.manualPage(students3, pageNum, pageSize); return studentsPage; } // 数据聚合场景下的手工分页 // 也适合EmptyList场景 Page{count=true, pageNum=1, pageSize=10, startRow=0, endRow=0, total=0, pages=0, reasonable=null, pageSizeZero=null} public static <E> Page<E> manualPage(List<E> res, Integer pageNum, Integer pageSize) { if (res == null) { res = new ArrayList<>(); } int pageNumber = PageUtils.getPageNum(pageNum); int sizePerPage = PageUtils.getPageSize(pageSize); int totalSize = res.size(); List<E> pageElements = res.stream().skip((long) (pageNumber - 1) * sizePerPage).limit(sizePerPage).toList(); // 分页 Page<E> page = new Page<>(); page.setPageNum(pageNumber); page.setPageSize(sizePerPage); page.setTotal(totalSize); page.setPages((totalSize / pageSize + ((totalSize % pageSize == 0) ? 0 : 1))); page.addAll(pageElements); return page; }

常见问题

[Q&A] 在系统中发现了多个分页插件