Servlet做简单的ajax增删改查（分页）

jdbc.java

 package servlet;

 import java.sql.Connection;
 import java.sql.DriverManager;
 import java.sql.ResultSet;
 import java.sql.SQLException;
 import java.sql.Statement;

 public class Jdbc {
     Connection conn;
     Statement stem;
     ResultSet re;
     /*
      * jdbc五步走：
      *          1:加载驱动
      *          2:创建连接
      *               2.1:地址
      *               2.2:用户名  root
      *               2.3:密码      123
      *          3:创建发送执行sql语句对象
      *          4:发送执行sql语句
      *          5:操作结果集
      */

     private void lianjie() {
         try {
              Class.forName("com.mysql.jdbc.Driver");
               conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/guoyihua", "root", "123");
              stem = conn.createStatement();
         } catch (Exception e) {
             e.printStackTrace();
         }
     }

     private void guanbi() {
         try {
             if (re!=null) {
                 re.close();
             }

             if (stem!=null) {
                 stem.close();
             }
             if (conn!=null) {
                 conn.close();
             }
         } catch (SQLException e) {
             // TODO Auto-generated catch block
             e.printStackTrace();
         }
     }

     /*
      * 创建一个应用于任何查询的show方法。
      * 但凡查询功能一定返回一个结果集
      */
     public   ResultSet   show (  String sql  ){
         this.lianjie();
         try {
             re=stem.executeQuery(sql);
         } catch (SQLException e) {
         }
         return  re;
     }

     public   int    update (  String sql  ){
         this.lianjie();
         int i;
         try {
             i = stem.executeUpdate(sql);
             this.guanbi();
             return i;
         } catch (SQLException e) {
         }
         return 0;
     }

 }

UserService.java

 package servlet;

 import java.sql.ResultSet;
 import java.sql.SQLException;
 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.Random;

 public class UserService {
     Jdbc jdbc= new Jdbc();

     int page=2;

     public List<Map<String, Object>> show(String ye) {
         int yee = Integer.parseInt(ye);
         yee=(yee-1)*page;
         List<Map<String, Object>> list  =new ArrayList<Map<String,Object>>();
         ResultSet show = jdbc.show("select * from user limit "+yee+" , "+page+" ");
         try {
             while (show.next()) {
                 Map<String,Object> map = new HashMap<String, Object>();
                 map.put("id", show.getInt("id"));
                 map.put("name", show.getString("name"));
                 map.put("password", show.getLong("password"));
                 list.add(map);
             }
         } catch (SQLException e) {
             // TODO Auto-generated catch block
             e.printStackTrace();
         }

         return list;
     }

     public void deletee(String id) {
         jdbc.update("delete from user where id='"+id+"' ");
     }

     public Map<String, Object> toupdate(String id) {
         Map<String, Object> map = new HashMap<String, Object>();
         ResultSet re = jdbc.show("select * from user where id='"+id+"'");
         try {
             while (re.next()) {
                 map.put("id", re.getInt("id"));
                 map.put("name", re.getString("name"));
                 map.put("password", re.getLong("password"));
             }
         } catch (SQLException e) {
             // TODO Auto-generated catch block
             e.printStackTrace();
         }
         return map;
     }

     public void update(String id, String name, String password) {
         jdbc.update("update user set name='"+name+"',password='"+password+"'where id='"+id+"'  ");
     }

     public void add(String name, String password) {
         Random random = new Random();
         int id = random.nextInt(1000);
         jdbc.update("insert into user (id,name,password) values('"+id+"','"+name+"','"+password+"')");
     }

     public int tablecount() {
         int tablecount=0;
         int count=0;
         ResultSet re = jdbc.show("select count(*) from  user ");
         try {
             while (re.next()) {
                  tablecount = re.getInt("count(*)");
             }
         } catch (SQLException e) {
             // TODO Auto-generated catch block
             e.printStackTrace();
         }
         if(tablecount%page==0){
             count = tablecount/page;
         }
         if (tablecount%page!=0) {

             count = tablecount/page+1;
         }
         return count;
     }

 }

UserServlet.java

 package servlet;

 import java.io.IOException;
 import java.io.UnsupportedEncodingException;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;

 import javax.servlet.ServletException;
 import javax.servlet.http.HttpServlet;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;

 public class UserServlet extends HttpServlet{
     List<Map<String, Object>> list= new ArrayList<Map<String,Object>>();
     UserService us = new UserService();
     HttpServletRequest request;
     HttpServletResponse response;
     protected void doGet(HttpServletRequest request, HttpServletResponse response)
             throws ServletException, IOException {
         this.request= request;
         this.response= response;
         String me = request.getParameter("method");
         if (me.equals("show")) {
             this.show();
         }
         if (me.equals("deletee")) {
             this.deletee();
         }
         if (me.equals("toupdate")) {
             this.toupdate();
         }
         if (me.equals("update")) {
             this.update();
         }if (me.equals("add")) {
             this.add();
         }
     }
     private void add() throws IOException {
         String name = request.getParameter("name");
         name=new String(name.getBytes("ISO8859-1"), "UTF-8");
         String password = request.getParameter("password");
         us.add(name,password);
         response.getWriter().print("<script type=\"text/javascript\">parent.show(1)</script>");
     }
     private void update() throws IOException {
         String id = request.getParameter("id");
         String name = request.getParameter("name");
         String password = request.getParameter("password");
         name= new String(name.getBytes("ISO8859-1"), "UTF-8");
         us.update(id,name,password);
         response.getWriter().print("<script type=\"text/javascript\">parent.show(1)</script>");
     }
     private void toupdate() throws ServletException, IOException {
         String id = request.getParameter("id");
         Map<String, Object> map = us.toupdate(id);
         request.setAttribute("map", map);
         request.getRequestDispatcher("update.jsp").forward(request, response);
     }
     private void deletee() throws ServletException, IOException {
         String id = request.getParameter("id");
         us.deletee(id);
         this.show();
     }
     private void show() throws ServletException, IOException {
         String ye = request.getParameter("ye");
         if (ye==null) {
             ye="1";
         }
         List<Map<String, Object>> list=us.show(ye);
         request.setAttribute("li", list);
         int count=us.tablecount();
         request.setAttribute("count", count);
         request.getRequestDispatcher("show.jsp").forward(request, response);

     }

 }

index.jsp

 <%@ 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 'index.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">
     <!--
     <link rel="stylesheet" type="text/css" href="styles.css">
     -->

   </head>
     <script type="text/javascript" src="jquery-1.6.js"></script>
     <script type="text/javascript">

     function show(ye){
         var d= new Date().getTime();
         $.get("aa?method=show&ye="+ye+"&d="+d,function(date){
         $("#div1").html(date)
             })
         }

     function deletee(id){
         var d=new Date().getTime();
         $.get("aa?method=deletee&id="+id+"&d="+d,function(date){
         $("#div1").html(date);
             })
     }

     function toupdate(id){
         $.get("aa?method=toupdate&id="+id,function(date){
         $("#div2").html(date);
             })
         }
     function update(a){
         a.submit();
         $(a).hide();
         }
     function toadd(){
         $.get("add.jsp",function(date){
         $("#div3").html(date);
             })
         }
     function add(a) {
         a.submit();
         $(a).hide();
     }
     </script>

   <body>
    <a href="javascript:show(1)">查询user表</a>
    <div id="div1"></div>
    <div id="div2"></div>
    <div id="div3"></div>
   </body>
 </html>

show.jsp

 <%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
 <%@taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
 <%
 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 'show.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">
     <!--
     <link rel="stylesheet" type="text/css" href="styles.css">
     -->

   </head>

   <body>
    <table bgcolor="c0c0c0"  bordercolor="green" cellspacing="1">
            <tr bordercolor="green">
                <td>编号</td>
                <td>姓名</td>
                <td>密码</td>
                <td>修改</td>
                <td>删除</td>
            </tr>
            <c:forEach items="${requestScope.li}" var="list">
                <tr>
                    <td>${list.id}</td>
                    <td>${list.name}</td>
                    <td>${list.password}</td>
                    <td><a href="javascript:toupdate(${list.id})">修改</a></td>
                    <td><a href="javascript:deletee(${list.id})">删除</a></td>
                </tr>
            </c:forEach>
    </table>

   <c:if test="${param.ye>1}">
        <a href="javascript:show(1)">首页</a>
   </c:if>
    <c:if test="${param.ye>1}">
    <a href="javascript:show(${param.ye-1})">上一页</a>
    </c:if>
        <c:forEach begin="1" end="${requestScope.count}" varStatus="c">
        <a href="javascript:show(${c.index})">${c.index}</a>
        </c:forEach>
        <c:if test="${param.ye<requestScope.count}">
    <a href="javascript:show(${param.ye+1})">下一页</a>
    </c:if>
   <c:if test="${param.ye<requestScope.count}">
        <a href="javascript:show(${requestScope.count})">尾页</a>
   </c:if>

        <a href="javascript:toadd()"> 添加 </a>
   </body>
 </html>

add.jsp

 <%@ 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 'add.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">
     <!--
     <link rel="stylesheet" type="text/css" href="styles.css">
     -->

   </head>

   <body>
   <form action="aa" target="abc">
       <h3>请输入以下内容</h3>
       <input type="hidden" name="id">
       <input type="hidden" name="method" value="add" >
       请输入姓名<input type="text" name="name" ><br/><br/>
       请输入密码<input type="text" name="password" ><br/><br/>
       <input type="button" value="确认添加" onclick="javascript:add(this.form)">
       <iframe name="abc" style="display: none;" frameborder="1"></iframe>
   </form>
   </body>
 </html>

update.jsp

 <%@ 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 'update.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">
     <!--
     <link rel="stylesheet" type="text/css" href="styles.css">
     -->

   </head>

   <body>
   <form action="aa" target="abc">
    <h3>请修改以下内容</h3>
     <input type="hidden" name="method" value="update">
     <input type="hidden" name="id" value="${map.id}"><br/><br/>
     <input type="text" name="name" value="${map.name}"><br/><br/>
     <input type="text" name="password" value="${map.password}"><br/><br/>
     <input type="button" value="确认修改" onclick="javascript:update(this.form)">
     <iframe name="abc" style="display: none;"></iframe>
   </form>
   </body>
 </html>

此文章仅为个人学习记录文件，为个人所记笔记。

可供大家参考

但是注释甚少

如有疑问可以留言

希望可以帮助到初学者

2017-08-1119:53:30