Public Release: 

Carnegie Mellon develops Java programming tools employing human-centered design techniques

Carnegie Mellon University

PITTSBURGH--Researchers at Carnegie Mellon University's School of Computer Science have developed two new tools to help computer programmers select from among thousands of options within the application programming interfaces (APIs) that are used to write applications in Java, today's most popular programming language.

The tools -- Jadeite ( and Apatite ( -- take advantage of human-centered design techniques to significantly reduce the time and guesswork associated with finding the right classes and methods of APIs.

APIs are standardized methods that a Java program uses to ask the computer's operating system or another program to do something, such as opening a file or sending an email. Choosing APIs for accomplishing a given task is at the heart of Java programming, but is not intuitive, said Brad A. Myers, professor of human-computer interaction. With more than 35,000 methods listed in 4,100 classes in the current Javadoc library of APIs -- and more being added in every new version -- not even the savviest developer can hope to be familiar with them all.


Jadeite (Java Documentation with Extra Information Tacked-on for Emphasis) improves usability by enhancing the existing Javadoc documentation. For instance, Jadeite displays the names of API classes in font sizes that correspond with how heavily used they are based on Google searches, helping programmers navigate past little-used classes. The commonly used "PrintWriter" is in large, prominent letters, while the lesser used "PrintEvent" is in smaller type.




Apatite (Associative Perusal of APIs That Identifies Targets Easily) takes a different approach, allowing programmers to browse APIs by association, seeing which packages, classes and methods tend to go with each other. It also uses statistics about the popularity of each item to provide weighted views of the most relevant items, listing them in larger fonts.





