What Problem Do Web Applications Solve?

• Individual Servlets Have Always Been Portable   Expand (p)

One of the great things about Java Servlets and Java Server Pages is their portability. You can create a Java Servlet, compile it and run it under Apache's servlet container and then run the same servlet, unchanged, under Allaire's JRun servlet container.

• Whole Web Applications Have Not Been Portable   Expand (p)

While portable servlets were a good thing, there were many aspects of the web application that were vendor specific.

• Things That Were Previously Vendor Specific   Expand (ul)
• How does one password protect certain html files and servlets?
• What directory should servlets be placed in?
• Where should other classes, that are called from the servlets, be placed?
• Where should jar files libraries be placed (i.e. a JDBC database driver)?
• Should any servlet's run on web server startup?
• Java's Web Application Makes the Whole Application Portable   Expand (p)

Java's Web Application solves all these problems by specifiying where servlets and class files should go (in a folder called classes), where jar files should go (in a folder called lib), where security privialges should be specified (in the deplayment descriptor - web.xml), etc.