Spring Data MongoDB 分页查询

痛定思痛。 2022-09-25 09:22 257阅读 0赞

在上篇文章 [Spring Data MongoDB 环境搭建][Spring Data MongoDB] 基础上进行分页查询

### 定义公用分页参数类，实现 Pageable 接口 ###

import java.io.Serializable;
    import org.springframework.data.domain.Pageable;
    import org.springframework.data.domain.Sort;
    
    public class SpringDataPageable implements Serializable, Pageable { 
        private static final long serialVersionUID = 1;
        // 当前页
        private Integer pagenumber = 1;
        // 当前页面条数
        private Integer pagesize = 10;
        // 排序条件
        private Sort sort;
    
        // 当前页面
        @Override
        public int getPageNumber() {
            return getPagenumber();
        }
    
        // 每一页显示的条数
        @Override
        public int getPageSize() {
            return getPagesize();
        }
    
        // 第二页所需要增加的数量
        @Override
        public int getOffset() {
            return (getPagenumber() - 1) * getPagesize();
        }
    
        @Override
        public Sort getSort() {
            return sort;
        }
    
        public Integer getPagenumber() {
            return pagenumber;
        }
    
        public void setPagenumber(Integer pagenumber) {
            this.pagenumber = pagenumber;
        }
    
        public Integer getPagesize() {
            return pagesize;
        }
    
        public void setPagesize(Integer pagesize) {
            this.pagesize = pagesize;
        }
    
        public void setSort(Sort sort) {
            this.sort = sort;
        }
    
        @Override
        public Pageable first() {
            // TODO Auto-generated method stub
            return null;
        }
    
        @Override
        public boolean hasPrevious() {
            // TODO Auto-generated method stub
            return false;
        }
    
        @Override
        public Pageable next() {
            // TODO Auto-generated method stub
            return null;
        }
    
        @Override
        public Pageable previousOrFirst() {
            // TODO Auto-generated method stub
            return null;
        }
    }

### 接口 PersonDao ###

/** * 分页查询 * @param pageNum 开始页 * @return */
    public Page<Person> paginationQuery(Integer pageNum);

### 接口实现 PersonDaoImpl ###

public Page<Person> paginationQuery(Integer pageNum) {
    
        SpringDataPageable pageable = new SpringDataPageable();
        Query query = new Query();
        List<Order> orders = new ArrayList<Order>();  //排序
        orders.add(new Order(Direction.DESC, "age"));
        Sort sort = new Sort(orders);
    
        // 开始页
        pageable.setPagenumber(pageNum);
        // 每页条数
        pageable.setPagesize(10);
        // 排序
        pageable.setSort(sort);
        // 查询出一共的条数
        Long count = mongoTemplate.count(query, Person.class);
        // 查询
        List<Person> list = mongoTemplate.find(query.with(pageable), Person.class);
        // 将集合与分页结果封装
        Page<Person> pagelist = new PageImpl<Person>(list, pageable, count);
    
        return pagelist;
    }

### 测试 ###

/** * 分页查询 */
    @Test
    public void paginationQuery(){
        Page<Person> persons = personDao.paginationQuery(2);
        for(Person p : persons){
            System.out.println(p.getName());
        }
    }

作者：[itmyhome][]

[Spring Data MongoDB]: http://blog.itmyhome.com/2016/08/spring-data-mongodb-environment-build
[itmyhome]: http://blog.csdn.net/itmyhome1990