JQuery+AJAX+servlet 数据库验证

<script src="jquery-1.4.2.min.js" type="text/javascript"></script>
  <script language = "javascript">
  function checkValue()
  {
         var buttonValue = document.getElementById("textfield").value;
        if(buttonValue.length == 0)
        {
            alert("输入不能为空！")
            document.getElementById("textfield").focus();
        }
        else
        {
            if(buttonValue.length!=11)
            {
                alert("手机的位数应为11位！");
                document.getElementById("textfield").value = "";
                document.getElementById("textfield").focus();
            }
            else
            {
                    $.ajax(
                    {
                        method:"get",  
                        url:"./WebLogin",
                        data:"buttonValue=" + buttonValue.toString(),
                        success:function(data)
                        {
                            if(data=="false")
                            {
                                alert("错误：您的手机号[" + buttonValue.toString() + "]未在系统中注册，无法执行重设密码功能。");
                            }
                            else
                            {
                                //提供更改密码服务
                                alert("准备更新密码，查收!");
                            }
                        }
                    });
            }
        }
  }
  </script>

以上是JS代码。

servlet代码：

 

import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
public class validate extends HttpServlet
{
	public validate()
	{
		super();
	}
	public void doGet(HttpServletRequest request, HttpServletResponse response)
  throws ServletException, IOException
	{
		try
		{
			//response.setContentType("text/html");
			//PrintWriter out = response.getWriter();
			String value = request.getParameter("buttonValue");
			//out.println(value);
			Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
			java.sql.Connection connection = java.sql.DriverManager.getConnection("jdbc:odbc:local", "sa", "bhdc818");
			java.sql.Statement statement = connection.createStatement();
			String sql = "select * from dbo.hh_User where UserId = '" + value + "'";
			java.sql.ResultSet rs = statement.executeQuery(sql);
			if (rs.next())
				response.getWriter().write("true");
			else
				response.getWriter().write("false");
		}
		catch (Exception e)
		{
			e.printStackTrace();
		}
	}
	public void doPost(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException
	{
		this.doGet(request, response);
	}
}

xml代码：

 

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.4"
    xmlns="http://java.sun.com/xml/ns/javaee"
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
  http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
 <servlet>
    <servlet-name>validate</servlet-name>
    <servlet-class>validate</servlet-class>
 </servlet>
 <servlet-mapping>
    <servlet-name>validate</servlet-name>
    <url-pattern>/WebLogin</url-pattern>
 </servlet-mapping>
</web-app>

 

附录：

工程目录下：

1.WEB-INF文件夹包括classes文件夹和web.xml!

2.修改完class要重启tomcat重新加载!

jsp代码：

 

<input type="button" value="重设密码" title="重设密码" onClick="checkValue()"/>
<input type="button" value="返回登陆页" title="返回" onClick="window.location.href='login.html';"/>