分页工具

佚名 6年前 (2019-05-06) 随笔 1928人围观抢沙发百度已收录

package cn.devil.utils;

import cn.devil.pojo.Admin;

import java.util.ArrayList;
import java.util.List;

public class PageUtil {

    //数据库开始下标0开始
    private int startIndex;
    //数据库结束下标
    private int endIndex;
    //页面存放数据数
    private int pageSize;
    //总页数
    private int totalPage;
    //数据总条数
    private int dataQuantity;
    //分页导航条开始
    private int navBarStart;
    //分页导航条结束
    private int navBarEnd;
    //当前页
    private int currentPage;
    // 当前查询数据
    private List<Admin> currentData;
    //是否可以上一页
    private boolean preview = false;
    //是否可以下一页
    private boolean next = false;

    public List<Admin> getCurrentData() {
        return currentData;
    }

    public void setCurrentData(List<Admin> currentData) {
        this.currentData = currentData;
    }

    public int getStartIndex() {
        if (startIndex < 0){
            this.startIndex = 0;
        }else{
            this.startIndex = (this.currentPage-1) * this.pageSize;
        }
        return startIndex;
    }

    public void setStartIndex(int startIndex) {
        this.startIndex = startIndex;
    }

    public int getEndIndex() {
        this.endIndex = this.startIndex + this.pageSize;
        if(this.endIndex > this.dataQuantity){
            this.endIndex = this.dataQuantity;
        }
        return endIndex;
    }

    public int getPageSize() {
        if(pageSize < 1){
            this.pageSize = 1;
        }
        return pageSize;
    }

    public void setPageSize(int pageSize) {
        this.pageSize = pageSize;
    }

    public int getTotalPage() {
        if(this.dataQuantity % this.pageSize == 0){
            this.totalPage = this.dataQuantity / this.pageSize;
        }else{
            this.totalPage = this.dataQuantity / this.pageSize + 1;
        }
        return totalPage;
    }

    public int getDataQuantity() {
        return dataQuantity;
    }

    public void setDataQuantity(int dataQuantity) {
        this.dataQuantity = dataQuantity;
    }

    public int getNavBarStart() {
        if(currentPage <= 6){
            this.navBarStart = 1;
        }else{
            this.navBarStart = this.currentPage-6;
        }
        return navBarStart;
    }

    public int getNavBarEnd() {
        if(this.navBarStart+9 < this.totalPage){
            this.navBarEnd = this.navBarStart+9;
        }else if (this.navBarEnd == 0 ){
            this.navBarEnd = this.navBarStart;
        }else{
            this.navBarEnd = this.totalPage;
        }
        return navBarEnd;
    }

    public void setNavBarEnd(int navBarEnd) {
        this.navBarEnd = navBarEnd;
    }

    public int getCurrentPage() {
        if(currentPage < 1){
            this.currentPage = 1;
        }else if(currentPage > this.totalPage){
            this.currentPage = this.totalPage;
        }
        return currentPage;
    }

    public void setCurrentPage(int currentPage) {
        this.currentPage = currentPage;
    }

    public static void main(String[] args) {
        List<Admin> admins = new ArrayList<>();
        for(int i = 0; i <= 20000; i++){
            Admin admin = new Admin();
            Long j = 1L;
            j++;
            admin.setAdminId(j);
            admins.add(admin);
        }
        PageUtil pageUtil = new PageUtil(admins,3,10);
        System.out.println("总页数："+pageUtil.getTotalPage());
        System.out.println("当前页第一条数据的下标："+pageUtil.getStartIndex());
        System.out.println("当前页最后一条数据的下标："+pageUtil.getEndIndex());
        System.out.println("导航条开始数："+pageUtil.getNavBarStart());
        System.out.println("导航条结束数："+pageUtil.getNavBarEnd());
        System.out.println("总页数："+pageUtil.getTotalPage());
    }

    public PageUtil(List<Admin> currentData, int currentPage, int pageSize) {
        this.dataQuantity = currentData.size();
        this.pageSize = pageSize;
        this.currentPage = currentPage;
        this.currentData = currentData;
        this.totalPage = this.getTotalPage();
        this.startIndex = this.getStartIndex();
        this.endIndex = this.getEndIndex();
        this.navBarStart = this.getNavBarStart();
        this.navBarEnd = this.getNavBarEnd();
        this.preview = this.isPreview();
        this.next = this.isNext();
    }

    public PageUtil(int startIndex, int pageSize, int dataQuantity, int currentPage, List<Admin> currentData) {
        this.startIndex = startIndex;
        this.pageSize = pageSize;
        this.dataQuantity = dataQuantity;
        this.currentPage = currentPage;
        this.currentData = currentData;
        this.totalPage = this.getTotalPage();
        this.startIndex = startIndex;
        this.endIndex = this.getEndIndex();
        this.navBarStart = this.getNavBarStart();
        this.navBarEnd = this.getNavBarEnd();
        this.preview = this.isPreview();
        this.next = this.isNext();
    }

    public boolean isPreview() {
        if(currentPage > 1){
            preview = true;
        }
        return preview;
    }

    public boolean isNext() {
        if(this.currentPage < this.totalPage ){
            next = true;
        }
        return next;
    }

}