eXtropia: the open web technology company
Technology | Support | Tutorials | Development | About Us | Users | Contact Us
 ::   Tutorials
 ::   Presentations
Perl & CGI tutorials
 ::   Intro to Perl/CGI and HTML Forms
 ::   Intro to Windows Perl
 ::   Intro to Perl 5
 ::   Intro to Perl
 ::   Intro to Perl Taint mode
 ::   Sherlock Holmes and the Case of the Broken CGI Script
 ::   Writing COM Components in Perl

Java tutorials
 ::   Intro to Java
 ::   Cross Browser Java

Misc technical tutorials
 ::   Intro to The Web Application Development Environment
 ::   Introduction to XML
 ::   Intro to Web Design
 ::   Intro to Web Security
 ::   Databases for Web Developers
 ::   UNIX for Web Developers
 ::   Intro to Adobe Photoshop
 ::   Web Programming 101
 ::   Introduction to Microsoft DNA

Misc non-technical tutorials
 ::   Misc Technopreneurship Docs
 ::   What is a Webmaster?
 ::   What is the open source business model?
 ::   Technical writing
 ::   Small and mid-sized businesses on the Web

Offsite tutorials
 ::   ISAPI Perl Primer
 ::   Serving up web server basics
 ::   Introduction to Java (Parts 1 and 2) in Slovak


Introduction to Web Programming
Throwing Errors  
  • In Java terms, errors are thrown to an event handler which catches it and processes it.

  • Thus, exception objects are always instances of the Throwable class and can be thrown from a routine to an error handler. In the following example, we see that the readLine() method might throw an IOException error object if it has trouble reading a line.

    public String readLine() throws IOException

  • It is also of interest to know that a method may throw multiple errors by listing them as a comma separated list after the "throws" keyword.

  • Of course, a method may perform correctly without throwing an error. The throws portion just allows the method to deal with the "other" cases.

  • You can also throw your own error objects including both those available through the JDK as well as ones you create yourself.

Previous Page | Next Page