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