java 分页工具类

Posted 2020-10-25 zwcry

//13年写的，今天（17）拷贝到博客园

package com.sicdt.sicsign.web.utils;

import java.io.Serializable;
import java.util.List;

/**
 * @author shizhenwei
 *
 * @param <T>用于向前台返还List所用
 */
public class PageInfo<T> implements Serializable {
    private static final long serialVersionUID = 1L;
     //每页显示的记录数
    private Integer pageSize;
     //当前页码数
    private Integer pageNum;
     //总记录数
    private Integer rowCount;
     //总页码数
    private Integer pageCount;
    //查询的时候从多少记录开始
    private Integer rowStart;
     //每页显示多少页码
    private Integer everyPageTabsCount;
     //每页显示的开始页码数
    private Integer everyPageStart;
     //每页显示的结束页码数
    private Integer everyPageEnd;
     //是否有上一页
    private boolean hasPrevious = false;
     //首页
    private Integer firstPageNum;
     //上一页
    private Integer priviousPageNum;
     //是否有下一页
    private boolean hasNext = false;
     //下一页
    private Integer nextPageNum;
     //尾页
    private Integer endPageNum;
     //存放本次分页查询出来的数据
    private List<T> list;

     /**
      * 通过构造器计算出其他属性的值
     * @param pageSize
      * @param pageNum
      * @param rowCount
      */
    public PageInfo(Integer pageNum,Integer pageSize,Integer rowCount,Integer everyPageTabsCount) {
         //每页显示的记录数
        this.pageSize = pageSize == null ? 10 : pageSize;
         //当前页码数
        this.pageNum = pageNum == null ? 1 : pageNum;
         //总记录数
        this.rowCount = rowCount == null ? 0 : rowCount;
        //每页显示多少页码 默认10，可以set
        this.everyPageTabsCount = everyPageTabsCount == null ? 10 : everyPageTabsCount;
         //总页码数
        this.pageCount = (int) Math.ceil(this.rowCount * 1.0 / this.pageSize);
         //判断当前页码数是否大于总页码数
        if (this.pageNum > this.pageCount && this.pageCount >= 1) {
           this.pageNum = this.pageCount;
        }
        //查询的时候从多少记录开始
        this.rowStart = (this.pageNum - 1) * this.pageSize;
        //每页显示的开始页码数        
        this.everyPageStart = (this.pageNum - this.everyPageTabsCount / 2) > 0 ? (this.pageNum - this.everyPageTabsCount / 2) : 1;
         

        /***** 无论从第几页开始都会以固定的页数进行显示，当总页数小于固定页数，将全部显示总页数****/
         int cenNum = (int) Math.ceil((this.everyPageTabsCount / 2.0));
         if(this.pageCount>=this.everyPageTabsCount && this.pageNum<=(this.everyPageTabsCount / 2)){
             this.everyPageEnd = this.everyPageTabsCount;
         }else if(this.pageCount<=this.everyPageTabsCount){
             this.everyPageEnd = this.pageCount;
         }else{
             //每页显示的结束页码数
            this.everyPageEnd = (this.pageNum + cenNum - 1) > this.pageCount ? this.pageCount : (this.pageNum + cenNum - 1);
         }
         if(this.pageCount>=this.everyPageTabsCount && this.pageNum>(this.pageCount-(cenNum - 1))){
             this.everyPageStart=this.pageCount-(this.everyPageTabsCount-1);
         }
         
         
        //是否有上一页
        if (this.pageNum > 1) {
             this.hasPrevious = true;
             this.firstPageNum = 1;
             this.priviousPageNum = this.pageNum - 1;
         }
         //是否有下一页
        if (this.pageNum < this.pageCount) {
             this.hasNext = true;
             this.nextPageNum = this.pageNum + 1;
             this.endPageNum = this.pageCount;
        }
    }

    public Integer getPageSize() {
        return pageSize;
    }

    public Integer getPageNum() {
        return pageNum;
    }

    public Integer getRowCount() {
        return rowCount;
    }

    public Integer getPageCount() {
        return pageCount;
    }

    public Integer getRowStart() {
        return rowStart;
    }

    public Integer getEveryPageStart() {
        return everyPageStart;
    }

    public Integer getEveryPageEnd() {
        return everyPageEnd;
    }

    public boolean isHasPrevious() {
        return hasPrevious;
    }

    public Integer getFirstPageNum() {
        return firstPageNum;
    }

    public Integer getPriviousPageNum() {
        return priviousPageNum;
    }

    public boolean isHasNext() {
        return hasNext;
    }

    public Integer getNextPageNum() {
        return nextPageNum;
    }

    public Integer getEndPageNum() {
        return endPageNum;
    }

    public List<T> getList() {
        return list;
    }

    public void setList(List<T> list) {
        this.list = list;
    }
    
    public Integer getEveryPageTabsCount() {
        return everyPageTabsCount;
    }

    public void setEveryPageTabsCount(Integer everyPageTabsCount) {
        this.everyPageTabsCount = everyPageTabsCount;
    }
}