自己写的分页Util类

最新推荐文章于 2020-09-09 14:37:20 发布

原创最新推荐文章于 2020-09-09 14:37:20 发布 · 704 阅读

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#hibernate #user #class #string #float #import

参考SpringSide的Page类，自己写了一个Page类，用于提供web页面的分页功能。该类：

不依赖实现逻辑，只封装了算法
接口清晰
通过测试

设计如下：

缺陷：

createPage的Hql需要用户自己写入，其实是依赖于hibernate的。

代码如下

Page

package com.rosicky.picenter.util.page; import java.util.List; public class Page<T> { private List<T> entities; private int PageNum; private int pageIndex; private int firstPage; private int lastPage; public int getPageNum() { return PageNum; } public Page(int pageNum, List<T> entities, int firstPage, int lastPage, int pageIndex) { super(); PageNum = pageNum; this.entities = entities; this.firstPage = firstPage; this.lastPage = lastPage; this.pageIndex = pageIndex; } public int nextPage() { return (pageIndex + 1) >= lastPage ? lastPage : (pageIndex + 1); } public int previousPage() { return (pageIndex - 1) <= 1 ? 1 : (pageIndex - 1); } public List<T> getResult() { return entities; } public int getFirstPage() { return firstPage; } public int getLastPage() { return lastPage; } public int pageNo() { return pageIndex; } public boolean hasNext() { return pageIndex != lastPage; } public boolean hasBefor() { return pageIndex != firstPage; } }

PageFactory

package com.rosicky.picenter.util.page; import java.util.List; public abstract class PageFactory<T> { public Page<T> createPage(String hql, int pageIndex, int PageNum) { List<T> entities = findEntities(hql, (pageIndex - 1) * PageNum + 1, PageNum); return new Page<T>(PageNum, entities, 1, Math.round((float)itemCount() / (float)PageNum), pageIndex); } abstract protected List<T> findEntities(String hql, int firstItem, int lastItem); abstract protected long itemCount(); }

Test

package test; import static org.junit.Assert.*; import org.junit.Test; import com.rosicky.picenter.entity.AddressBook; import com.rosicky.picenter.entity.User; import com.rosicky.picenter.service.AddressBookSupport; import com.rosicky.picenter.util.page.Page; public class TestService extends SuperTest { @Test public void testFindAddressPage() { AddressBookSupport abs = (AddressBookSupport) context .getBean("addressBookSupport"); User user = new User(); user.setId(1); Page<AddressBook> page = abs.findAddressPage(user, 7); assertEquals(page.getResult().size(),5); } }