json实现jsp分页实例介绍(附效果图)

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

复制代码 代码如下:

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

复制代码 代码如下:

[{},{},{}]

3.将此字符串 返回到请求页面

复制代码 代码如下:

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 list = new LinkedList();
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

复制代码 代码如下:

var mgs = xmlHttpRequest.responseText;
var persons = mgs.evalJSON();

将json数据解析 并添加到显示的区域

复制代码 代码如下:

<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>

id

用户名

密码

age

另外：要有这两个js哦

复制代码 代码如下: