html与javascript的结合

[size=16px][b]<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html><head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<script  type="text/javascript" src="dwr/interface/ud.js"></script>
<script  type="text/javascript" src="dwr/engine.js"></script>
<script  type="text/javascript" src="dwr/util.js"></script>
<script language="javascript">
   
function  go()
{ 
     if(dwr.util.getValue("name")=="")
    {
          alter("必须填写登录名称！");
          return false;
     }
   else      ud.addUser(dwr.util.getValue("name"),showJ);
}
function showJ(v)
{
      if(v==0)
             alert("注册失败，登录名已经存在。");
      if(v==1)
              alert("注册成功。");
}
</script>
</head><body>
<center><h2>DWR</h2></center>
<table width="63%" height="202" border="0" align="center">
  <tr>
      <td><center>登录名称<input type="text" id="name"></center></td></tr>
<tr>
      <td><center><input type="button" name="submit"  value="注册"  onClick="go()"></center></td></tr>
</table>
</body>
</html>
为什么点注册后没反应？

解决方案 »

  1.   

    你的页面中引到了 DWR 框架中的 JS，请先检查 DWR 配置是否正确，如果没有正确配置 DWR 的话，if(dwr.util.getValue("name")=="") 这一行会提示 dwr is not defined。
      

  2.   

    DWR怎么配置？是把dwr.jar解压后放在WEB-INF\lib\目录下？
    这个我配置了，跟这个代码一块的还有三个文件web.xml userDAO.java  dwr.xml
    具体代码如下：
    web.xml
    <?xml version="1.0" encoding="UTF-8"?>
        <web-app version="2.4"
    xmlns="http://java.sun.com/xml/ns/j2ee"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://java.suncom/xml/ns/j2eee
    http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">
            <servlet>
                  <servlet-name>dwr-invoker</servlet-name>
                  <servlet-class>org.directwebremoting.servlet.DwrServlet</servlet-class>
                   <init-param>
                            <param-name>debug</param-name>
                             <param-value>false</param-value>
                   </init-param>
             </servlet>
                    <servlet-mapping>
                           <servlet-name>dwr-invoker</servlet-name>
                           <url-pattern>/dwr/*</url-pattern>
                   </servlet-mapping>
       </web-app>
      userDAO.java
            package   com;
            import java.sql.*;
     
           public class userDAO
           {
                    private  static Connection conn;
                    private   Statement  state;
                    private ResultSet rs;

     
                   public userDAO(){
                
    if(conn==null){
                                               try{
                                                       Class.forName("com.mysql.jdbc.Driver").newInstance();//装载数据库连接驱动
                                                     conn=DriverManager.getConnection("jdbc:mysql://localhost:3306/jspajax?useUnicode=true&amp; characterEncoding=utf-8","root","19841025");
                                                     }
                                                catch(Exception e){
                                                               e.printStackTrace();
                                                                                  }
                                                }
                                              }              public int addUser(String name){
                                   int v=0;
                           
                                   try{
                                              state=conn.createStatement();
                                               rs=state.executeQuery("select*from user where logname='"+name+"'");  //重名查询
                                                if(rs.next())
                                                            v=0; 
                                                else
                                                            v=state.executeUpdate("insert into user values ('"+name+"')");
                                              }
                                    catch(SQLException e){
                                                           e.printStackTrace();
                                                                            }
                                      finally
                                            {
                                                      try{
                                                                  rs.close();
                                                                  state.close();
                                                             }
                                                       catch(SQLException e){
                                                                       e.printStackTrace();
                                                                     }
                                               }
                                        return v;
                                    }
                                           
            }
    dwr.xml
    <?xml version="1.0" encoding="UTF-8"?>
               <dwr>
                        <allow>
                                    <create  creator="new" javascript="ud">
                   <param name="class" value="com.userDAO"/>
                                     </create>
                          </allow>
                 </dwr>