I am calling java method in jsp page that is showing servlet.service exception nosuch method exception or class

<%@page import="java.util.ArrayList"%>
<%@page import="Model.Validation"%>
<%
String username=request.getParameter("uname");
String password=request.getParameter("password");
System.out.print(username+"\nhellloo\n"+password+"\n re\n");
ArrayList<String> names=Validation.validateuname(username,password);
String name=(String)names.get(0);
String role=(String)names.get(1);
if(role.equals("Administrator"))
{
out.print("{success:true,errors:{reason:'Administrator'},uname:{name:'"+name+"'}}");

}else if(role.equals("User"))
{
out.print("{success:true,errors:{reason:'User'}}");

}else
{
out.print("{success:false,errors:{reason:'User name or Password is wrong, please try again'}}");

}

%>
SEVERE: Servlet.service() for servlet jsp threw exception java.lang.NoSuchMethodError: Model.Validation.validateuname(Ljava/lang/String;Ljava/lang/StringLjava/util/ArrayList; at org.apache.jsp.check_005flogin_jsp._jspService(check_005flogin_jsp.java:61) at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70) at javax.servlet.http.HttpServlet.service(HttpServlet.java:717) at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:388) at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:313) at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:260) at javax.servlet.http.HttpServlet.service(HttpServlet.java:717) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:293) at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:859) at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:602) at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489) at java.lang.Thread.run(Unknown Source)