Use multiple catch statement in single jsp
In java a single try can have multiple catch
statements. The code bound by the try block need not always throw a single
exception so we can use multiple catches or Exception class (base class of all
exceptions). When exception occurs while executing any statement within try
block, control enters into the catch blocks until it finds its matching block.
If catch block containing
the Exception class object then the subsequent catch blocks will not be executed.
If the appropriate exception object is not found and Exception class is also not
used in program, the java complier gives an error stating that the subsequent
catch blocks have not been reached. This is known as Unreachable code problem.
To resolve this, the last catch block in multiple catch blocks must contain the
Exception class object.
The example below 'multi_catches_jsp.jsp'
will show you how to use multiple catch
blocks to handle multiple exceptions. This program encounters problem with
arithmetic calculation , so throwing Arithmetic Exception. To handle any other
type of exception which has not been handled, we have used catch block with
Exception object.
multi_catches_jsp.jsp
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
"http://www.w3.org/TR/html4/loose.dtd">
<HTML>
<HEAD>
<TITLE>multiple catch in single jsp program</TITLE>
</HEAD>
<BODY>
<% try {
int arithmeticExp = 10/0;
}
// Multiple catch statement
catch(ArithmeticException aEx){
out.println("Arithmetic Exception : "+aEx);
}
catch(Exception ex){
out.println("Exception : "+ex);
}
%>
</body>
</html>
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Save this code as a .jsp file named "multi_catches_jsp.jsp"
in your application directory ('user' in our example) in Tomcat server and run this jsp page with
url http://localhost:8080/user/multi_catches_jsp.jsp
in address bar of the browser.
Download Source Code
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