Kude e greshkata?

TOVA E SORS KODA NA SERVLET -A KOITO SUM NAPISAL PRI KOMPILIRANETO I TESTVANETO NA KOMPIUTARA NA KOITO RABOTIA NE DAVA GRESHKI, NO NESHTATA NE STOIAT TAKA KATO SE KACHI NA SERVER.


package message;

import java.io.*;
import java.lang.*;
import java.util.*;
import javax.servlet.*;
import javax.servlet.http.*;

public class Main extends HttpServlet {

public void doPost(HttpServletRequest request,HttpServletResponse response) throws ServletException, IOException {
response.setContentType("text/html");
PrintWriter out = response.getWriter();
String title = "Your final scores";
int score = 0;
int pos = 0;
String msg = null;
String mail = request.getParameter("email");
StringBuffer mailUrl = new StringBuffer(mail);
for(int i=0;i<mailUrl.length();i++) {
char ch = mailUrl.charAt(i);
if(ch!='@')
pos++;
else
break;
}
String temp = mailUrl.substring(pos+1,mailUrl.length());
String finalUrl = new String(temp);
Enumeration e = request.getParameterNames();
while(e.hasMoreElements()) {
String paramName = (String)e.nextElement();
String[] paramValues = request.getParameterValues(paramName);
for(int i=0;i<paramValues.length;i++) {
if(paramValues.equals("true")) {
score++;
}
}
}
if(score<=5) {
msg = new String("Вашият резултат от проведения тест е "+score+" съветваме ви да се съсредоточите повече върху необходимата литература!");
}
else {
msg = new String("Вашият резултат от проведения тест е "+score+" Вие притежавате необходимите знания в дадената област!");
}
try {
MessageSend message = new MessageSend();
message.postMail(mail,"Final result",msg,"@",finalUrl);
}
catch (Exception ex) {

}
out.println("<HTML><HEAD></HEAD>");
out.println("<BODY BGCOLOR=\"#FDF5E6\">");
out.println("<H1 ALIGN=\"center\">"+title+"</H1>");
out.println("Your final result has been sent!");
out.println("</BODY></HTML>");
}
}


A ETO I GRESHKATA KOIATO MI DAVA PREZ BROWSE -RA


Error: 500
Location: /Message/servlet/message.Main
Internal Servlet Error:

java.lang.NoSuchMethodError: java.lang.StringBuffer: method substring(II)Ljava/lang/String; not found
at message.Main.doPost(Main.java:21)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:760)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
at org.apache.tomcat.facade.ServletHandler.doService(ServletHandler.java:484)
at org.apache.tomcat.core.Handler.invoke(Handler.java:322)
at org.apache.tomcat.core.Handler.service(Handler.java:235)
at org.apache.tomcat.facade.ServletHandler.service(ServletHandler.java:432)
at org.apache.tomcat.core.ContextManager.internalService(ContextManager.java:917)
at org.apache.tomcat.core.ContextManager.service(ContextManager.java:833)
at org.apache.tomcat.modules.server.Http10Interceptor.processConnection(Http10Interceptor.java:161)
at org.apache.tomcat.util.net.TcpWorkerThread.runIt(PoolTcpEndpoint.java:477)
at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:519)
at java.lang.Thread.run(Thread.java)

koia e versiata na tomcat na server-a?method-yt public String substring(intstart, intend) na StringBuffer go ima ot jdk1.2 nagore..ako servlet container-yt e very ancient(jdk1.1 compatible) bi se dyrjalo taka..

Na server -a nie jdk1.1 a na kompiutara na koito go napisah e jdk1.3.1. Tova li e problema?

da,StringBiffer niama takyv method v jdk1.1

OK Shte go smenia i shte vidia kakvo shte stane