javaw

Java support

Javac is one of the few compilers that behaves very badly:

  1. it outputs files where it wants to (-d is only for the package root)

  2. it recompiles files silently behind your back

  3. it outputs an undefined amount of files (inner classes)

Remember that the compilation can be performed using Jython[1] rather than regular Python. Instead of running one of the following commands:

./waf configure
python waf configure

You would have to run:

java -jar /path/to/jython.jar waf configure

[1] http://www.jython.org/

Usage

Load the “java” tool.

def configure(conf):

conf.load(‘java’)

Java tools will be autodetected and eventually, if present, the quite standard JAVA_HOME environment variable will be used. The also standard CLASSPATH variable is used for library searching.

In configuration phase checks can be done on the system environment, for example to check if a class is known in the classpath:

conf.check_java_class('java.io.FileOutputStream')

or if the system supports JNI applications building:

conf.check_jni_headers()

The java tool supports compiling java code, creating jar files and creating javadoc documentation. This can be either done separately or together in a single definition. For example to manage them separately:

bld(features  = 'javac',
        srcdir    = 'src',
        compat    = '1.7',
        use       = 'animals',
        name      = 'cats-src',
)

bld(features  = 'jar',
        basedir   = '.',
        destfile  = '../cats.jar',
        name      = 'cats',
        use       = 'cats-src'
)

Or together by defining all the needed attributes:

bld(features   = 'javac jar javadoc',
        srcdir     = 'src/',  # folder containing the sources to compile
        outdir     = 'src',   # folder where to output the classes (in the build directory)
        compat     = '1.6',   # java compatibility version number
        classpath  = ['.', '..'],

        # jar
        basedir    = 'src', # folder containing the classes and other files to package (must match outdir)
        destfile   = 'foo.jar', # do not put the destfile in the folder of the java classes!
        use        = 'NNN',
        jaropts    = ['-C', 'default/src/', '.'], # can be used to give files
        manifest   = 'src/Manifest.mf', # Manifest file to include

        # javadoc
        javadoc_package = ['com.meow' , 'com.meow.truc.bar', 'com.meow.truc.foo'],
        javadoc_output  = 'javadoc',
)

External jar dependencies can be mapped to a standard waf “use” dependency by setting an environment variable with a CLASSPATH prefix in the configuration, for example:

conf.env.CLASSPATH_NNN = ['aaaa.jar', 'bbbb.jar']

and then NNN can be freely used in rules as:

use        = 'NNN',

In the java tool the dependencies via use are not transitive by default, as this necessity depends on the code. To enable recursive dependency scanning use on a specific rule:

recurse_use = True

Or build-wise by setting RECURSE_JAVA:

bld.env.RECURSE_JAVA = True

Unit tests can be integrated in the waf unit test environment using the javatest extra.

Features defined in this module: