Java™ Application Development on Linux - Dator

5.5 Complete, Up-to-Date Program Documentation Made Easy123documentation by default, but this is because it uses a doclet that producesHTML documentation. You can write your own doclet that produces whateverformat you wish. Most find the HTML documentation so satisfactory thatcustom doclets are rare.Javadoc can be a large topic, because it not only documents all classes,methods, and class variables, but can also use detailed text from specially formattedcomments in the source code. We will cover Javadoc comments onlybriefly here, but you will see examples in our project code throughout this book.5.5.1 Running javadocThe javadoc command has the following general form:javadoc [options...] [package names...] [source filenames...][@optfile...]Options are covered in the next section. You can specify the classes todocument in two ways. First, you can list one or more Java packages on thecommand line. Source code for the named packages is searched for on thesource classpath (see Section 5.5.2). Wildcards are not permitted inpackage names.Second, you may list as many Java source files as you like, and you mayuse wildcards in the names.As with the javac compiler above, the @optfile allows you to name a textfile whose lines are treated as arguments as if they had been typed on the commandline.Example 5.5 shows how to run javadoc on our small multiclass sample.In this case, we were in the “base directory” of the package when we ranthe command. In other words, net was a subdirectory of the current workingdirectory when we ran Javadoc. Javadoc uses the same default classpaths andenvironment variables as javac does, so by default “.” is on the path.Generally, specifying packages is the most convenient way to document anumber of classes, since packages are how collections of classes are generallymanaged in Java development.Figure 5.1 shows the main screen of the documentation thus produced.