This language feature lets you avoid writing boilerplate code under many circumstances by enabling tools to generate it from annotations in the source code. This leads to a declarative programming style where the programmer says what should be done and tools emit the code to do it. Also it eliminates the need for maintaining side files that must be kept up to date with changes in source files. Instead the information can be maintained in the source file. Refer to JSR 175 and to the documentation at http://java.sun.com/j2se/1.5.0/docs/guide/language/annotations.html.