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trupti nigam
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Hi,
I am getting the following error when i try to load the JSP in my browser. can somebody let me know what is the problem?
ERROR:
Error: 500
Location: /examples/jsp/num/numguessByPrad.jsp
Internal Servlet Error:
javax.servlet.ServletException: Cannot create bean of class num.NumberGuessBeanNew
at jsp.num.numguessByPrad_10._jspService(numguessByPrad_10.java:74)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:119)
at javax.servlet.http.HttpServlet.service(HttpServlet.java)
at org.apache.tomcat.facade.ServletHandler.doService(ServletHandler.java:574)
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:485)
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:176)
at org.apache.tomcat.util.net.TcpWorkerThread.runIt(PoolTcpEndpoint.java:494)
at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:516)
at java.lang.Thread.run(Thread.java:484)
Root cause:
java.lang.ClassNotFoundException: class num.NumberGuessBeanNew : java.lang.ArithmeticException: / by zero
at java.beans.Beans.instantiate(Beans.java:211)
at java.beans.Beans.instantiate(Beans.java:51)
at jsp.num.numguessByPrad_10._jspService(numguessByPrad_10.java:72)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:119)
at javax.servlet.http.HttpServlet.service(HttpServlet.java)
at org.apache.tomcat.facade.ServletHandler.doService(ServletHandler.java:574)
at org.apache.tomcat.core.Handler.invoke(Handler.java:322)
at org.apache.tomcat.core.Handler.service(Handler.java:235)
at org.apache.tomcat.facade.ServletHandler.service(ServletHandler.java:485)
at org.apache.tomcat.core.ContextManager.internalService(ContextManager.java:917)
at org.apache.tomcat.core.ContextManager.service(ContextManager.java:833)
at org.apache.tomcat.modules.server.Http10Interceptor.processConnection(Http10Interceptor.java:176)
at org.apache.tomcat.util.net.TcpWorkerThread.runIt(PoolTcpEndpoint.java:494)
at
org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:516)
at java.lang.Thread.run(Thread.java:484)
The code for numguessByPrad.jsp
<%@ page import = "num.NumberGuessBeanNew" %>
<jsp:useBean id="numguess1" class="num.NumberGuessBeanNew" scope="session"/>
<jsp:setProperty name="numguess" property="*"/>
<html>
<head><title>Number Guess</title></head>
<body bgcolor="white">
<font size=4>
<% if (numguess1.getSuccess()) { %>
Congratulations! You got it.
And after just <%= numguess1.getNumGuesses() %> tries.<p>

<%numguess1.resetMain();%>

Care to <a href="numguessByPrad.jsp">try again</a>?
<% } else if (numguess1.getNumGuesses() == 0) { %>

Welcome to the Number Guess game modified by Pradnya.<p>
The Lower number will always start from 0. Enter the upper limit.<p>

<form method=get>
Enter the upper limit: <input type=text name=upper>
<input type=submit value="Submit">

<%
if ( request.getParameter("upper") != null ) {
%>
<%@ include file="next.jsp" %>
<%
}
%>


</form>



<% } else { %>
Good guess, but nope. Try <b><%= numguess1.getHint() %></b>.
You have made <%= numguess1.getNumGuesses() %> guesses.<p>

<form method=get>
What's your guess? <input type=text name=guess>
<input type=submit value="Submit">
</form>
<% } %>
</font>
</body>
</html>
The code for response.jsp
<%@ page import = "num.NumberGuessBeanNew" %>
<jsp:useBean id="numguess" class="num.NumberGuessBeanNew" scope="session"/>
<jsp:setProperty name="numguess" property="*"/>
<html>
<head><title>Number Guess</title></head>
<body bgcolor="white">
<font size=4>
<% if (numguess.getSuccess()) { %>
Congratulations! You got it.
And after just <%= numguess.getNumGuesses() %> tries.<p>

<%numguess.resetMain();%>

Care to <a href="numguessByPrad.jsp">try again</a>?
<% } else if (numguess.getNumGuesses() == 0) { %>

Now guess what number is in my mind?<p>
<form method=get>
What's your guess? <input type=text name=guess>
<input type=submit value="Submit">
</form>


<% } else { %>
Good guess, but nope. Try <b><%= numguess.getHint() %></b>.
You have made <%= numguess.getNumGuesses() %> guesses.<p>

<form method=get>
What's your guess? <input type=text name=guess>
<input type=submit value="Submit">
</form>
<% } %>
</font>
</body>
</html>
and the code for NumberGuessBeanNew.java
package num;
import java.util.*;
public class NumberGuessBeanNew {
int answer;
boolean success;
String hint;
int numGuesses;
int upper1 = 0;

public NumberGuessBeanNew() {
resetMain();
}
public void setGuess(String guess) {
numGuesses++;
int g;
try {
g = Integer.parseInt(guess);
}
catch (NumberFormatException e) {
g = -1;
}
if (g == answer) {
success = true;
}
else if (g == -1) {
hint = "a number next time";
}
else if (g < answer) {
hint = "higher";
}
else if (g > answer) {
hint = "lower";
}
}
public void setUpper(String upper)
{

upper1 = Integer.parseInt(upper);
reset(upper1);

}

public boolean getSuccess() {
return success;
}
public String getHint() {
return "" + hint;
}
public int getNumGuesses() {
return numGuesses;
}
public void reset(int upper) {

answer = Math.abs(new Random().nextInt(upper) % upper) + 1;
success = false;
numGuesses = 0;
}

public void resetMain() {
answer = Math.abs(new Random().nextInt() % upper1) + 1;
success = false;
numGuesses = 0;
}


}
It's a time consuming process going through the code but please somebody take time to go through it & let me know the error.I am stuck due to this.
Thanks In advance..
Trupti
 
Carl Trusiak
Sheriff
Posts: 3341
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java.lang.ClassNotFoundException
You don't have the class in the proper location.
If you don't have it in a jar, the NumberGuessBeanNew.class file goes in the
WEB-INF/classes/num
directory.
Otherwise, the jar file it's in goes in the
WEB-INF/lib directory.
 
Vladan Radovanovic
Ranch Hand
Posts: 216
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Originally posted by trupti nigam:
Hi,
javax.servlet.ServletException: Cannot create bean of class num.NumberGuessBeanNew
Root cause:
java.lang.ClassNotFoundException: class num.NumberGuessBeanNew : java.lang.ArithmeticException: / by zero

Well, you see here ClassNotFoundException so where is your num.NumberGuessBeanNew class file located? It should be in WEB-INF\classes\num dir.

Take care of that first and see where does this Arithmetic devide by zero Exception come from.
HTH
 
trupti nigam
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Now that the first problem is gone..
In the browser the first jsp i.e. the numguessByPrad gets loaded but from this JSP i am invoking a new jsp called the response JSP . the moment i enter the upper limit & click on submit instead of getting the new JSP page i get the followning nullPointer exception.
Error: 500
Location: /examples/jsp/num/numguessByPrad.jsp
Internal Servlet Error:
org.apache.jasper.JasperException
at org.apache.jasper.runtime.JspRuntimeLibrary.introspecthelper(JspRuntimeLibrary.java:200)
at org.apache.jasper.runtime.JspRuntimeLibrary.introspect(JspRuntimeLibrary.java:148)
at jsp.num.numguessByPrad_10._jspService(numguessByPrad_10.java:89)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:119)
at javax.servlet.http.HttpServlet.service(HttpServlet.java)
at org.apache.tomcat.facade.ServletHandler.doService(ServletHandler.java:574)
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:485)
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:176)
at org.apache.tomcat.util.net.TcpWorkerThread.runIt(PoolTcpEndpoint.java:494)
at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:516)
at java.lang.Thread.run(Thread.java:484)
Root cause:
java.lang.NullPointerException
at org.apache.jasper.runtime.JspRuntimeLibrary.introspecthelper(JspRuntimeLibrary.java:162)
at org.apache.jasper.runtime.JspRuntimeLibrary.introspect(JspRuntimeLibrary.java:148)
at jsp.num.numguessByPrad_10._jspService(numguessByPrad_10.java:89)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:119)
at javax.servlet.http.HttpServlet.service(HttpServlet.java)
at org.apache.tomcat.facade.ServletHandler.doService(ServletHandler.java:574)
at org.apache.tomcat.core.Handler.invoke(Handler.java:322)
at org.apache.tomcat.core.Handler.service(Handler.java:235)
at org.apache.tomcat.facade.ServletHandler.service(ServletHandler.java:485)
at org.apache.tomcat.core.ContextManager.internalService(ContextManager.java:917)
at org.apache.tomcat.core.ContextManager.service(ContextManager.java:833)
at org.apache.tomcat.modules.server.Http10Interceptor.processConnection(Http10Interceptor.java:176)
at org.apache.tomcat.util.net.TcpWorkerThread.runIt(PoolTcpEndpoint.java:494)
at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:516)
at java.lang.Thread.run(Thread.java:484)
Let me know where i am wrong.
Thanks in advance.
Trupti
 
trupti nigam
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Posts: 640
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please somebody let me know why i am getting the null pointer exception.
I can't go further,
One correction to the include file action.
I have done little correction i.e.
<%@ include file="/jsp/num/next.jsp" %>
in the numguessByPrad.jsp
thanks,
Trupti
 
Don't get me started about those stupid light bulbs.
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