javac - The Java Compiler

SYNOPSIS

javac_g [ options ] filename.java...

DESCRIPTION

Every class defined in the files passed to javac has its resulting bytecodes stored in a file named classname.class. The .class file is stored in the same directory as the corresponding .java file, unless the -d option is used. If a class in one of the files passed to javac references a class not in any of the files passed to javac then javac searches for the referenced class using the class path.

When you define your own classes you need to specify their location. Use CLASSPATH to do this. CLASSPATH consists of a colon separated list of directories that specifies the path. For example:

    .:/home/avh/classes

javac_g is a non-optimized version of javac suitable for use with debuggers like dbx or gdb.

OPTIONS

-classpath path

Specifies the path javac uses to look up classes. Overrides the default or the CLASSPATH environment variable if it is set. Directories are separated by colons. Thus the general format for path is:

    .:<your_path>

For example:

    .:/home/avh/classes:/usr/local/java/classes

-d directory

Specifies the root directory of the class hierarchy. Thus doing:

    javac -d <my_dir>/editor/gui/TextWindow.java

causes the class file for the class called editor.gui.Textwindow to be saved as:

    <my_dir>/editor/gui/TextWindow.class

-g

Enables generation of debugging tables. Debugging tables contain information about line numbers and local variables - information used by debugging tools. By default, this option is on. To turn debugging table generation off, use the -ng option.

-ng

Disables generation of debugging tables. This makes the Java bytecode files smaller, but makes it impossible for debugging tools to access local variables or print out line numbers.

-nowarn

Turns off warnings. If used the compiler does not print out any warnings.

-O

Optimizes compiled code by inlining static, final and private methods. Note that your classes may get larger in size.

-verbose

Causes the compiler and linker to print out messages about what source files are being compiled and what class files are being loaded.

ENVIRONMENT VARIABLES

CLASSPATH

Used to provide the system a path to user-defined classes. Directories are separated by colons, for example,

    .:/home/avh/classes:/usr/local/java/classes

SEE ALSO