分页进阶--ajax+jquery+struts2

时间：2023-02-13 01:57:17

　　按照上次的分页逻辑，分页查询的业务大概需要几个“零件”：1.当前页；2.总页数；3.跳转页。后端需要处理的是：按照传送过来请求的页码返回相应地数据，并且接受初始化参数的请求：总页码、第一页的数据。

　　使用ajax请求可以很轻易地和服务器交互，所需要的数据格式是json。json的好处是可以把大量的数据格式化成一条字符串，由前后端的程序进行解析并呈现内容。我把查询到的数据装入list，并用struts自带的工具转换成为json返回客户端。

　　前端程序如下：

<!DOCTYPE html>

<html>

<head>

<meta charset="UTF-8">

<title>Insert title here</title>

<script type="text/javascript" src="js/jquery.min.js"></script>

<script type="text/javascript" src="js/pager.js"></script>

</head>

<body>

    <div >

        <table id="content" border="1">

        </table>

    </div>

    <div id="guide">

        <!-- 只输入数字的输入框 -->

        <button id="prePage" type="button">上一页</button> 当前 第 <span id="current"></span> 页/共 <span id="total"></span> 页  跳转到<input id="jumpPage" size="5" type="text" onkeyup='this.value=this.value.replace(/\D/gi,"")'/> <button id="jumpBtn">跳转到</button>  <button id="nextPage" type="button">下一页</button>

    </div>

</body>

</html>
/*

 * To change this license header, choose License Headers in Project Properties.

 * To change this template file, choose Tools | Templates

 * and open the template in the editor.

 */

var totalPage;

var currentPage;

var userlist;

//初始化请求--将当前页和总页面初始化 和 list

$(document).ready(function(){

    $.get('Init','',function(results){

        $.each(results, function(key, val) {

             if(key === "current")

                 currentPage = results[key];

             else if(key === "total")

                 totalPage = results[key];

             else if(key == "list"){

                userlist=val;

             }

        });

        currentPage = parseInt(currentPage);

        totalPage = parseInt(totalPage);

        $("#current").text(currentPage);

        $("#total").text(totalPage);

        getUser(userlist);

        //console.log(currentPage);

        //console.log(totalPage);

    });

});

//上一页

$(document).ready(function(){

    $('#prePage').click(function(){

        if(currentPage == 1)

            alert("已至首页");

        else{

            currentPage = currentPage-1;

            var need=currentPage;

            $.get('Pager','need='+need,function(result){

                userlist = result['userList'];

                getUser(userlist);

                $('#current').text(need);

            });

            }

    });

});

//下一页

$(document).ready(function(){

    $('#nextPage').click(function(){

        if(currentPage == totalPage)

            alert("已至尾页");

        else{

            currentPage = currentPage+1;

            var need=currentPage;

            $.get('Pager','need='+need,function(result){

                userlist = result['userList'];

                getUser(userlist);

                //console.log(need);

                $('#current').text(need);

            });

        }

    });

});

//跳转页

$(document).ready(function(){

    $('#jumpBtn').click(function(){

        var toPage = $('#jumpPage').val();

        if(toPage != ""){

            toPage = parseInt(toPage);

            if(toPage <= totalPage && toPage >=1)

                $.get('Pager','need='+toPage,function(result){

                    userlist = result['userList'];

                    getUser(userlist);

                    //console.log(need);

                    $('#current').text(toPage);

                });

            else {

                alert("跳转页不合法!");

            }

        }

    });

});

//遍历list并生成table

function getUser(list){

    //先清空再添加

    var table = $('#content');

    table.html("");

    var thead = $("<tr></tr>");

    thead.appendTo(table);

    var tagName = $("<td>id</td>");

    tagName.appendTo(thead);

    tagName = $("<td>name</td>");

    tagName.appendTo(thead);

    tagName = $("<td>sex</td>");

    tagName.appendTo(thead);

    tagName = $("<td>age</td>");

    tagName.appendTo(thead);

    for(var k in list){

        var tr=$("<tr></tr>");

        tr.appendTo(table);

        var person = new Object();

        var td;

        person.id=userlist[k]['id'];

        person.name=userlist[k]['name'];

        person.sex=userlist[k]['sex'];

        person.age=userlist[k]['age'];

        td=$("<td>"+person.id+"</td>");

        td.appendTo(tr);

        td=$("<td>"+person.name+"</td>");

        td.appendTo(tr);

        td=$("<td>"+person.sex+"</td>");

        td.appendTo(tr);

        td=$("<td>"+person.age+"</td>");

        td.appendTo(tr);

        //console.log(person);

    }

}

　　后端逻辑为：

package ActionPackage;

import java.util.HashMap;

import java.util.List;

import javax.servlet.http.HttpServletRequest;

import org.apache.struts2.ServletActionContext;

import com.opensymphony.xwork2.ActionSupport;

import model.test_u;

import pagetest.PageService;

public class PageAction extends ActionSupport{

    private HashMap<String,Object> dataMap;

    private List<test_u> userList;

    public List<test_u> getUserList() {

        return userList;

    }

    public void setUserList(List<test_u> userList) {

        this.userList = userList;

    }

    private int size=10;

    public String Pager(){

        HttpServletRequest request = ServletActionContext.getRequest();

        int need = Integer.parseInt(request.getParameter("need"));

        System.out.println("need = "+need);

        PageService ps = new PageService();

        userList = ps.selectLimit((need-1)*size, size);

        return SUCCESS;

    }

    public String Init(){

        System.out.println("访问了！");

        PageService ps = new PageService();

        int total = ps.getConut()/10;

//        HttpServletResponse response = ServletActionContext.getResponse();

        dataMap = new HashMap<String,Object>();

        dataMap.put("current", 1);

        dataMap.put("total", total);

        List list = ps.selectLimit(1, size);

        dataMap.put("list", list);

//        String jsonString="{\"current\":1,\"totle\":12}";

//        try {

//            response.getWriter().print(jsonString);

//        } catch (IOException e) {

//            // TODO Auto-generated catch block

//            e.printStackTrace();

//        }

        return SUCCESS;

    }

    public HashMap<String, Object> getDataMap() {

        return dataMap;

    }

    public void setDataMap(HashMap<String, Object> dataMap) {

        this.dataMap = dataMap;

    }

}

　　模型层与DAO层与service层如上篇分页一样。

        <action name="Pager" class="ActionPackage.PageAction" method="Pager">

                <result type="json">

                <!-- 这里指定将被Struts2序列化的属性，该属性在action中必须有对应的getter方法 -->

                <param name="root1">userList</param>

            </result>

        </action>

        <action name="Init" class="ActionPackage.PageAction" method="Init">

             <result type="json">

                <!-- 这里指定将被Struts2序列化的属性，该属性在action中必须有对应的getter方法 -->

                <param name="root">dataMap</param>

            </result>

        </action>

　　主要难题：json对象的解析。因为前端代码不是很熟悉，查了很多资料，传回来的数据是Object Object类型的，其实用for循环加上k，v访问就ok了。最后记录动态表格生成的代码。

    var table = $('#content');

    table.html("");

    var thead = $("<tr></tr>");

    thead.appendTo(table);

    var tagName = $("<td>id</td>");

    tagName.appendTo(thead);

    tagName = $("<td>name</td>");

    tagName.appendTo(thead);

    tagName = $("<td>sex</td>");

    tagName.appendTo(thead);

    tagName = $("<td>age</td>");

    tagName.appendTo(thead);

　　效果图：

　　分页进阶--ajax+jquery+struts2

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