Ajax实现实时注册验证

--注册表单页面


  
    
    
    
    
 

  
  
  
  
 

    
  
注册:
    用户名
  
  
  

    密码
  
  
    
  
    
 
  

--jsAjax页面

$(function(){
	initEvent();
})

//注册验证
function initEvent(){
	$("#name").bind("change",function(){
		$.get("servlet/UserServlet?type=getUserByName",{"name":this.value},function(data){
			
			if(data==1)
				$("#span1").html("用户名已存在!不可用");
			else
				$("#span1").html("可以使用！");
		});
	})
}
--servlet处理页面
public class UserServlet extends HttpServlet {
	IUserService service=new UserServiceImpl();
	public void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		request.setCharacterEncoding("utf-8");
		response.setCharacterEncoding("UTF-8");
		String type=request.getParameter("type");
		try {
			Method mt=UserServlet.class.getMethod(type, HttpServletRequest.class,HttpServletResponse.class);
			try {
				mt.invoke(this, request,response);
			} catch (IllegalAccessException e) {
				e.printStackTrace();
			} catch (IllegalArgumentException e) {
				e.printStackTrace();
			} catch (InvocationTargetException e) {
				e.printStackTrace();
			}
		} catch (NoSuchMethodException e) {
			e.printStackTrace();
		} catch (SecurityException e) {
			e.printStackTrace();
		}
	}
	public void getUserByName(HttpServletRequest request,HttpServletResponse response) throws ServletException,IOException{
		String name =request.getParameter("name"); 
		System.out.println(name);
		if(service.getUserByName(name))
			response.getWriter().print("1");
		else
			response.getWriter().print("2");
			
	}
	public void doPost(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		this.doGet(request, response);
	}

}
--dao层访问页面
public class UserDaoImpl implements IUserDao{
	public boolean getUserByName(String name){
		String sql="select * from userinfo where name=?";
		List