Answer:
Below example describe the exception handling concept in JSP page. The exception class works same as simple java program. There are 3 files in this example index.html, process.html, error.jsp.
index.html
<html>
<head>
<title>Exception Example</title>
</head>
<body>
<form action="process.jsp">
<fieldset style="width:20%; background-color:#e6ffe6;">
<center>
<h3>Exception Example</h3>
Enter number: <input type="text" name="n1" /><br/><br/>
Enter number: <input type="text" name="n2" /><br/><br/>
<input type="submit" value="Divide"/>
</center>
</fieldset>
</form>
</body>
</html>
process.jsp
<%@ page errorPage="error.jsp" %>
<%
String num1=request.getParameter("n1");
String num2=request.getParameter("n2");
int a=Integer.parseInt(num1);
int b=Integer.parseInt(num2);
int c=a/b;
out.print("Division of numbers is: "+c);
%>
error.jsp
<%@ page isErrorPage="true" %>
<h3>Sorry an exception occured!</h3>
Exception is: <%= exception %>
web.xml
<web-app>
<servlet>
<servlet-name>xyz</servlet-name>
<jsp-file>/index.jsp</jsp-file>
</servlet>
<servlet-mapping>
<servlet-name>xyz</servlet-name>
<url-pattern>/test</url-pattern>
</servlet-mapping>
</web-app>
Output:
Click the "Divide" button.
Division of numbers is: 5
When we enter valid number for division it gives proper output.
However, if we enter invalid number or leave any box blank, it gives error message.
Click the "Divide" button.
