Exceptions Example

• Numbers.jsp will add two numbers together.

An example to demonstrate exception handling.
If the input data are not well formed or do not exist, error.jsp will catch the exception.

Brandan Jones
University of Cincinnati
jonesbr@email.uc.edu
December 26, 2001
--%>

<%-- <jsp:useBean id="beanInstanceName" scope="session" class="package.class" /> --%>
<%-- <jsp:getProperty name="beanInstanceName"  property="propertyName" /> --%>
<%@ page errorPage="error.jsp" %>
 

If entered correctly, you will see the total of the two numbers you sent me.
<%
String strFirstNumber = request.getParameter("firstNumber");
String strSecondNumber = request.getParameter("secondNumber");
int total = Integer.parseInt(strFirstNumber) + Integer.parseInt(strSecondNumber);
out.print("<h2>The total of the numbers is: " + total);
%>
 

</body>
</html>
 

• But, if you fail to enter two numbers, or if the input data are not numeric, error.jsp will handle the exception.

<%-- <jsp:useBean id="beanInstanceName" scope="session" class="package.class" /> --%>
<%-- <jsp:getProperty name="beanInstanceName"  property="propertyName" /> --%>

<%@ page isErrorPage="true" %>
Exception caught while attempting to hanlde your request: <%= exception %>.
<br>Stack Trace:
<br><% exception.printStackTrace(new PrintWriter(out)); %>

</body>
</html>

 The Results
 

Created by:  Brandan Jones December 20, 2001