简单的分页

1.定义PageBean

package com.shenqz.util;

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

import org.apache.poi.ss.formula.functions.T;

/**
 * 
 * @author Administrator
 *
 * @param <T>
 */
@SuppressWarnings("hiding")
public class PageBean<T> implements Serializable {

private static final long serialVersionUID = -6710532081301192385L;

    /**
    * 基本属性分析：
    * 1.当前页 currentPage
    * 2.每页多少数据 pageSize
    * 3.数据总条数 totalCount
    * 4.总页数 pageCount
    * 5.数据集合 List<T> list
    * 6.每页显示的最多的页码数 pageNumSize
    * 7.拼接的分页字符串 pageHtml
    */
    private int currentPage = 1;
    
    private int pageSize = 2;
    
    private int totalCount;
    
    private int pageCount;
    
    private List<T> list;
    
    private int pageNumSize = 5;
    
    private String pageHtml;
    /**
    * 基本逻辑分析：
    * 1.list总数判断得出totalCount和pageCount
    * 2.currentPage*pageSize得出startRow和endRow
    * 3.通过list.submit(startRow,endRow)得出需要展示的当前页的数据;
    * 4.通过currentPage、pageSize、totalCount、pageCount拼出分页html字符串前台
    * 需要拼接的项目有首页、上一页、下一页、末页以及中间具体页码
    * 5.前台点击上述项目时，ajax传递currentPage和pageSize及查询条件至后台
    * 6.根据查询条件查询出list，和currentPage和PageSize传入PageBean对象生成需要展示的list以及分页html
    */
    
    /**
    * <p>Description: pageBean初始化方法</p>
    * @param list 数据集合 currentPage 页面传递的当前页码 pageSize 页面传递的pageSize
    */
    public void initPage(List<T> list, Integer currentPage){
        //1.初始化各属性的值
        if(currentPage != null && currentPage >= 1){
            this.currentPage = currentPage;
        }
        
        this.list = list;
        this.totalCount = this.list.size();
        this.pageCount = totalCount%this.pageSize == 0?totalCount/this.pageSize:totalCount/this.pageSize+1;
        int startRow = (this.currentPage-1)*this.pageSize;
        int endRow = this.currentPage*this.pageSize;
        if(endRow > list.size()){
            endRow = list.size();
        }
        //2.拼接分页html
        this.pageHtml = initPageHtml();
        //3.截取list
        if(!this.list.isEmpty()){
            this.list = this.list.subList(startRow, endRow);
        }
    }
    
    /**
    * 拼接分页html
    */
    public String initPageHtml(){
        /**
        * 基本逻辑分析：
        * 1.判断list是否为空
        * 2.根据currentPage判断是否有首页、上一页、下一页、末页
        */
        StringBuffer sb = new StringBuffer();
        if(!this.list.isEmpty()){
            /**
            * 样式及hover
            */
            String background = "background: #2db3c1;border: 1px solid #2db3c1;color: #fff;";
            String style = "text-decoration:none;padding: 8px 10px;margin-left: 3px;border: 1px solid #cdcccc;color: #2db3c1;cursor: pointer;max- 50px;";
            String hover = "onmouseover="$(this).attr('style','"+style+background+"');" onmouseout="$(this).attr('style','"+style+"');"";
            
            //页面拼接开始
            String firstPage = "<a href='javascript:skipToPage(1);' style=""+style+"""+hover+">首页</a>";
            sb.append(firstPage);
            
            String prePage = "";
            if(this.currentPage != 1){
                prePage = "<a href='javascript:skipToPage("+(this.currentPage-1)+");' style=""+style+"""+hover+">上一页</a>";
            }else{
                prePage = "<a href='javascript:skipToPage("+(this.currentPage-1)+");' style=""+style+"display:none;""+hover+">上一页</a>";
            }
            sb.append(prePage);
            //当前页小于每页页码数时，默认从第一个开始
            int num = 1;
            //当前页大于每页页码数时
            if(this.currentPage >= pageNumSize){
                if((this.currentPage+(pageNumSize-1)/2) >= this.pageCount ){
                    num = this.currentPage-(this.pageNumSize-(this.pageCount+1-this.currentPage));
                }else{
                    num = this.currentPage - (pageNumSize-1)/2;
                }
            }
            
            int endNum = (num+pageNumSize-1) > pageCount ?pageCount:(num+pageNumSize-1);
            for(int i = num; i <= endNum; i++){
                String select = "";
                String pageNumHtml = "&nbsp;<a href='javascript:skipToPage("+i+");' style=""+style+"""+hover+">"+i+"</a>";
                if(this.currentPage == i){
                    select = background;
                    pageNumHtml = "&nbsp;<a href='javascript:skipToPage("+i+");' style=""+style+select+"">"+i+"</a>";
                }
                sb.append(pageNumHtml);
            }
            String nextPage = "";
            if(this.currentPage != this.pageCount){
                nextPage = "<a href='javascript:skipToPage("+(this.currentPage+1)+");' style=""+style+"""+hover+">下一页</a>";
            }else{
                nextPage = "<a href='javascript:skipToPage("+(this.currentPage+1)+");' style=""+style+"display:none;""+hover+">下一页</a>";
            }
            sb.append(nextPage);
            
            String endPage = "<a href='javascript:skipToPage("+this.pageCount+");' style=""+style+"""+hover+">末页</a>";
            sb.append(endPage);
            
            sb.append("第<input size=3 maxlength=6 id='currentPage' value="
                    + this.currentPage + ">页　"
                    + "<a href=javascript:ToPage(document.getElementById('currentPage').value)>Go</a>");
            
            sb.append(" 共" + this.pageCount + "页 ");
            sb.append("每页<input size=3 maxlength=6 id='pageSize' value=" + this.pageSize + ">条 ");
            
            String counyStr = "<span>共"+totalCount+"条数据</span>";
            sb.append(counyStr);
        }
        return sb.toString();
    }
    
    public int getCurrentPage() {
        return currentPage;
    }
    
    public void setCurrentPage(int currentPage) {
        if(currentPage >= 1){
            this.currentPage = currentPage;
        }
    }
    
    public int getPageSize() {
        return pageSize;
    }
    
    public void setPageSize(int pageSize) {
        if(pageSize >= 1){
            this.pageSize = pageSize;
        }
    }
    
    public int getTotalCount() {
        return totalCount;
    }
    
    public int getPageCount() {
        return pageCount;
    }
    
    public int getPageNumSize() {
        return pageNumSize;
    }
    
    public void setPageNumSize(int pageNumSize) {
        if(pageNumSize >= 1){
            this.pageNumSize = pageNumSize;
        }
    }
    
    public List<T> getList() {
        return list;
    }
    
    public String getPageHtml() {
        return pageHtml;
    }
}

2.controller

package com.shenqz.controller;

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

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;

import com.alibaba.fastjson.JSONArray;
import com.alibaba.fastjson.JSONObject;
import com.shenqz.entity.User;
import com.shenqz.util.PageBean;

@Controller
public class PageController {
    private PageBean<User> page;
    public PageController(){
        page = new PageBean<User>(); 
    }
    
    @RequestMapping("page.do")
    @ResponseBody
    public String pageHtml(Integer cur,Integer pageSize){
        List<User> list = new ArrayList<User>();
        list.add(new User("shenqz", 27, "15357000000"));
        list.add(new User("shenqz1", 27, "15357000000"));
        list.add(new User("shenqz2", 27, "15357000000"));
        list.add(new User("shenqz3", 27, "15357000000"));
        list.add(new User("shenqz4", 27, "15357000000"));
        list.add(new User("shenqz5", 27, "15357000000"));
        list.add(new User("shenqz6", 27, "15357000000"));
        list.add(new User("shenqz7", 27, "15357000000"));
        list.add(new User("shenqz8", 27, "15357000000"));
        list.add(new User("shenqz9", 27, "15357000000"));
        list.add(new User("shenqz10", 27, "15357000000"));
        list.add(new User("shenqz11", 27, "15357000000"));
        list.add(new User("shenqz12", 27, "15357000000"));
        list.add(new User("shenqz13", 27, "15357000000"));
        list.add(new User("shenqz14", 27, "15357000000"));
        list.add(new User("shenqz15", 27, "15357000000"));
        list.add(new User("shenqz16", 27, "15357000000"));
        list.add(new User("shenqz17", 27, "15357000000"));
        list.add(new User("shenqz18", 27, "15357000000"));
        list.add(new User("shenqz19", 27, "15357000000"));
        list.add(new User("shenqz20", 27, "15357000000"));
        /*PageBean<User> page = new PageBean<User>(); */
        if(cur != null){
            page.setCurrentPage(cur);
        }
        if(pageSize != null){
            if(pageSize != page.getPageSize()){
                page.setPageSize(pageSize);
                page.setCurrentPage(1);
            }
        }
        System.out.println("pageSize:"+page.getPageSize());
        page.initPage(list, page.getCurrentPage());
        String str = page.initPageHtml();
        JSONObject object = new JSONObject();
        object.put("page", str);
        object.put("list", page.getList());
        return object.toJSONString();
        
    }
    
    public static void main(String[] args) {
        PageBean<User> page = new PageBean<User>(); 
        System.out.println(page.getCurrentPage());
    }
}

3.jsp页面

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>首页</title>
    <script type="text/javascript" src="js/jquery-1.8.3.js"></script>  
    <script type="text/javascript">
        
        function skipToPage(cur){
            var pageSize = $("#pageSize").val();
            queryList(cur,pageSize);
        }
        function ToPage(cur){
            skipToPage(cur)
        }
        function queryList(cur,pageSize){
            $.ajax({
                url : "page.do",
                data : {"cur":cur,"pageSize":pageSize},
                async : true,
                type : "post",
                dataType : "json",
                success : function(data){
                    var str = JSON.stringify(data.page);
                    str = str.replace(/"/g, "");
                    var list ; 
                     $("#d2").text("");
                    $.each(data.list,function(k){
                        list+="<tr><td>"+data.list[k].username+"</td><td>"+data.list[k].age+"</td><td>"+data.list[k].iphone+"</td></tr>"
                    });
                    
                    $("#d2").append(list);
                    $("#d2").append(str);
                },
                error :function(){
                    
                }
            })
        }
    </script>
</head>
<body>
    <a href = "javascript:void(0)" onclick = "queryList();">查询所有</a>
    <div id="d2"></div>
</body>
</html>

4.页面效果