struts2与ajax交互

实现动态检验用户是否在数据库中存在.

一:JSP页面

<script type="text/javascript" src="JS/Ajax.js"
<script type="text/javascript">  
  function
if(value!=""){  
"get","check?usersName="+value,deal,null);  
  }  
 }
</script>
<form action="register" method="post"  id="form1">  
  <table>  
   <tr>  
      <td>用户名：</td>
      <td>
"text" name="usersName" οnblur="checkUsersName(this.value)"/>
"check">这里显示检测结果信息</div>
      </td>  
      </tr>  
      <tr>  
       <td>
"submit" value="注册"/>
       </td>
       <td>
"reset" value="重置"/>
        </td>
     </tr>  
   </table>  
  </form>

二:Action接收请求并处理,并返回结果

public String checkUserName()
  {
HttpServletResponse response=ServletActionContext.getResponse();
   response.setContentType("text/html");
   response.setCharacterEncoding("utf-8");
   PrintWriter out = null;
   try {
out=response.getWriter();
   } catch (IOException e1) {
    // TODO Auto-generated catch block
    e1.printStackTrace();
   }
   String name="";
   try {
//页面传递usersName过来，这里涉及到中文转码
 name=java.net.URLDecoder.decode(usersName,"UTF-8");
   } catch (UnsupportedEncodingException e) {
    // TODO Auto-generated catch block
    e.printStackTrace();
   }
//存在返回1，否则返回0
if(rs.checkUserExit(name)!=null) // 进行数据库校验
    { 
      exit="1";
      out.print(exit);
      out.flush();
      out.close();
      System.out.println(exit);
    } 
  
  return null;}

三:Struts配置文件

<action name="check" class="com.article.action.RegisterAction" method="checkUserName">  
<result>register.jsp</result>
</action>

上面的<result></result>里面可以不写，如果报错，就写个已存在的页面，不会跳转的，注册页面与action交互，action里execute的返回值必须为空！