Java Cookbook

Automating Compilation with make

Problem

You get tired of typing javac and java commands.

Solution

Use the make utility to direct your compilations.

Discussion

The Unix operating system has long had to deal with automating large or repetitive compilations. The most enduring tool for this purpose is make, invented by Stu Feldman at Bell Laboratories in the mid-1970s and still widely used. There have been literally dozens of make -like programs over the years. The X Window System has imake, which is really a front-end to make. Linux and GNU enthusiasts have gmake, and BSD systems feature BSD make; one or another will be installed under the name make. The cygwin32 project features its own make, a version of gmake. make consults a file called Makefile (or makefile ) in the current directory to figure out what you want done and how to do it. A makefile to build one Java program could be as simple as this:

all:
    javac HelloWorld.java

Makefiles can be much more involved. One common feature is to parameterize a makefile so that if you need to port the code to a new platform or you distribute your source code to others to port, all the necessary makefile changes are in one place. For example, to use make variables to let the user compile with either javac or Jikes, and to add a rule to remove the *.class files after a round of debugging, the makefile might grow somewhat, as shown here. Note that lines beginning with the pound sign (#) are comments for the reader and are ignored by make : ...