json 在上篇文章已有详细介绍，json的既简单易懂，又传输迅速。并且能和javascript很好的融为一体。
在不需要添加jar的前提下，能够很好完成jsp分页问题。
下面具体介绍分页实例：
效果如图所示，采用jsp+servlet技术
首先：编写一个javabean user.java
package bean;
public class user {
private int id;
private string name;
private string password;
private int age;
public user() {
super();
}
public user(int id, string name, string password, int age) {
super();
this.id = id;
this.name = name;
this.password = password;
this.age = age;
}
public int getid() {
return id;
}
public void setid(int id) {
this.id = id;
}
public string getname() {
return name;
}
public void setname(string name) {
this.name = name;
}
public string getpassword() {
return password;
}
public void setpassword(string password) {
this.password = password;
}
public int getage() {
return age;
}
public void setage(int age) {
this.age = age;
}
@override
public string tostring() {
//{'id':1,'name':'zhangsan','password':'123','age':1}
return "{'id':"+id+",'name':'"+name+"','password':'"+password+"','age':"+age+"}";
}
}
这里需要注意的 就是 tostring的方法的改变
然后：我们来编写它的control 层和dao层
为了简化代码，便于取值，数据库暂写为一个集合
可以看到，
1.service 接收request请求 得到页面所要展示当前页（为第page页）
2.创建一个字符串，向内依次添加 从数据库db 得到的user，并将所有数据封装
[{},{},{}]
3.将此字符串 返回到请求页面
package servlet;
import java.io.ioexception;
import java.io.printwriter;
import java.util.linkedlist;
import java.util.list;
import javax.servlet.servletexception;
import javax.servlet.http.httpservlet;
import javax.servlet.http.httpservletrequest;
import javax.servlet.http.httpservletresponse;
import bean.user;
public class paging extends httpservlet {
public static final int per_page = 3;
@override
protected void service(httpservletrequest request, httpservletresponse response)
throws servletexception, ioexception {
//分页 数据源 当前得到第几页的记录 每页显示多少条
int page = integer.parseint(request.getparameter("page"));
// page = 1 i = 0
//page = 2 3
int length = 0;//记录当前拿了多少条
stringbuffer sb = new stringbuffer();
sb.append("[");
//[{},{},{}]
string message = null;
if(page >= 1 && page <= 3){
for (int i = (page-1)*per_page; i < db.list.size()&&length < per_page; i++) {
user u = db.list.get(i);
sb.append(u.tostring()+",");
length++;
}
if(length > 0){
message = sb.substring(0, sb.length()-1)+"]";
}else{
message = sb.tostring()+"]";
}
}else{
response.setcontenttype("text/html;charset=utf-8");
response.getwriter().println("捣乱");
return;
}
response.setcontenttype("text/html;charset=utf-8");
response.getwriter().println(message);
}
}
class db{
public static list<user> list = new linkedlist<user>();
static{
list.add(new user(1,"zhangsan","zs",34));
list.add(new user(2,"lisi","ls",34));
list.add(new user(3,"a","h",34));
list.add(new user(4,"b","d",34));
list.add(new user(5,"c","g",34));
list.add(new user(6,"d","a",34));
list.add(new user(7,"e","d",34));
list.add(new user(8,"f","e",34));
list.add(new user(9,"g","a",34));
}
}
之后 ：jsp的填写，通过ajax异步提交page，然后得到相应的字符串
var mgs = xmlhttprequest.responsetext;
var persons = mgs.evaljson();
将json数据解析 并添加到显示的区域
<%@ page language="java" import="java.util.*" pageencoding="utf-8"%>
<%
string path = request.getcontextpath();
string basepath = request.getscheme()+"://"+request.getservername()+":"+request.getserverport()+path+"/";
%>
<!doctype html public "-//w3c//dtd html 4.01 transitional//en">
<html>
<head>
<base href="<%=basepath%>">
<title>my jsp 'regist.jsp' starting page</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="this is my page">
<script type="text/javascript" src="js/prototype1.6.js"></script>
<script type="text/javascript" src="js/jquery-1.4.4.js"></script>
<script type="text/javascript">
var paging = 0;
//
function page(p){
/*if(p == 'next' && paging < 3){
paging ++;
}else if(p == 'last' && paging > 1) {
paging --;
}else{
alert('错误');
}*/
if(p == 'next' && paging < 3){
paging ++;
if(paging > 1){
$(":button:eq(0)").removeattr('disabled');
}
if(paging == 3){
$(":button:eq(1)").attr('disabled','disabled');
}
}else if(p == 'last' && paging > 1){
paging --;
$(":button:eq(1)").removeattr('disabled');
if(paging == 1){
$(":button:eq(0)").attr('disabled','disabled');
}
}
createxmlhttprequest();
xmlhttprequest.onreadystatechange=back;
var url = encodeuri("/json_page/paging?page="+paging);
xmlhttprequest.open("get",url,true);
xmlhttprequest.send(null);
}
//假设名字为xmlhttprequest
function createxmlhttprequest(){
if(window.activexobject){
xmlhttprequest = new activexobject("microsoft.xmlhttp");
}else{
xmlhttprequest = new xmlhttprequest();
}
}
//回调函数
function back(){
if( xmlhttprequest.readystate == 4 && xmlhttprequest.status == 200){
var mgs = xmlhttprequest.responsetext;
var persons = mgs.evaljson();
//alert(mgs);
$("table").empty();
$("table").append( $("<tr><td>id</td><td>用户名</td><td>密码</td><td>age</td></tr>"));
for(var i = 0 ; i < persons.length;i++){
var person = persons[i];
var $tr = $("<tr><td>"+person.id+"</td><td>"+person.name+"</td><td>"+person.password+"</td><td>"+person.age+"</td></tr>");
$("table").append($tr);
}
}
}
</script>
</head>
<body>
<input type="button" disabled="disabled" value="上一页" onclick="page('last');"/><input type="button" value="下一页" onclick = "page('next');"/>
<table>
<tr><td>id</td><td>用户名</td><td>密码</td><td>age</td></tr>
</table>
</body>
</html>
另外：要有这两个js哦
<script type="text/javascript" src="js/prototype1.6.js"></script>
<script type="text/javascript" src="js/jquery-1.4.4.js"></script>
更多json实现jsp分页实例介绍(附效果图)。