forked from mirrors/nixpkgs
85 lines
2.6 KiB
XML
85 lines
2.6 KiB
XML
|
<section xmlns="http://docbook.org/ns/docbook"
|
|||
|
|
xmlns:xlink="http://www.w3.org/1999/xlink"
|
|||
|
|
xml:id="sec-language-java">
|
|||
|
|
|
|||
|
|
<title>Java</title>
|
|||
|
|
|
|||
|
|
<para>Ant-based Java packages are typically built from source as follows:
|
|||
|
|
|
|||
|
|
<programlisting>
|
|||
|
|
stdenv.mkDerivation {
|
|||
|
|
name = "...";
|
|||
|
|
src = fetchurl { ... };
|
|||
|
|
|
|||
|
|
buildInputs = [ jdk ant ];
|
|||
|
|
|
|||
|
|
buildPhase = "ant";
|
|||
|
|
}
|
|||
|
|
</programlisting>
|
|||
|
|
|
|||
|
|
Note that <varname>jdk</varname> is an alias for the OpenJDK.</para>
|
|||
|
|
|
|||
|
|
<para>JAR files that are intended to be used by other packages should
|
|||
|
|
be installed in <filename>$out/share/java</filename>. The OpenJDK has
|
|||
|
|
a stdenv setup hook that adds any JARs in the
|
|||
|
|
<filename>share/java</filename> directories of the build inputs to the
|
|||
|
|
<envar>CLASSPATH</envar> environment variable. For instance, if the
|
|||
|
|
package <literal>libfoo</literal> installs a JAR named
|
|||
|
|
<filename>foo.jar</filename> in its <filename>share/java</filename>
|
|||
|
|
directory, and another package declares the attribute
|
|||
|
|
|
|||
|
|
<programlisting>
|
|||
|
|
buildInputs = [ jdk libfoo ];
|
|||
|
|
</programlisting>
|
|||
|
|
|
|||
|
|
then <envar>CLASSPATH</envar> will be set to
|
|||
|
|
<filename>/nix/store/...-libfoo/share/java/foo.jar</filename>.</para>
|
|||
|
|
|
|||
|
|
<para>Private JARs
|
|||
|
|
should be installed in a location like
|
|||
|
|
<filename>$out/share/<replaceable>package-name</replaceable></filename>.</para>
|
|||
|
|
|
|||
|
|
<para>If your Java package provides a program, you need to generate a
|
|||
|
|
wrapper script to run it using the OpenJRE. You can use
|
|||
|
|
<literal>makeWrapper</literal> for this:
|
|||
|
|
|
|||
|
|
<programlisting>
|
|||
|
|
buildInputs = [ makeWrapper ];
|
|||
|
|
|
|||
|
|
installPhase =
|
|||
|
|
''
|
|||
|
|
mkdir -p $out/bin
|
|||
|
|
makeWrapper ${jre}/bin/java $out/bin/foo \
|
|||
|
|
--add-flags "-cp $out/share/java/foo.jar org.foo.Main"
|
|||
|
|
'';
|
|||
|
|
</programlisting>
|
|||
|
|
|
|||
|
|
Note the use of <literal>jre</literal>, which is the part of the
|
|||
|
|
OpenJDK package that contains the Java Runtime Environment. By using
|
|||
|
|
<literal>${jre}/bin/java</literal> instead of
|
|||
|
|
<literal>${jdk}/bin/java</literal>, you prevent your package from
|
|||
|
|
depending on the JDK at runtime.</para>
|
|||
|
|
|
|||
|
|
<para>It is possible to use a different Java compiler than
|
|||
|
|
<command>javac</command> from the OpenJDK. For instance, to use the
|
|||
|
|
Eclipse Java Compiler:
|
|||
|
|
|
|||
|
|
<programlisting>
|
|||
|
|
buildInputs = [ jre ant ecj ];
|
|||
|
|
</programlisting>
|
|||
|
|
|
|||
|
|
(Note that here you don’t need the full JDK as an input, but just the
|
|||
|
|
JRE.) The ECJ has a stdenv setup hook that sets some environment
|
|||
|
|
variables to cause Ant to use ECJ, but this doesn’t work with all Ant
|
|||
|
|
files. Similarly, you can use the GNU Java Compiler:
|
|||
|
|
|
|||
|
|
<programlisting>
|
|||
|
|
buildInputs = [ gcj ant ];
|
|||
|
|
</programlisting>
|
|||
|
|
|
|||
|
|
Here, Ant will automatically use <command>gij</command> (the GNU Java
|
|||
|
|
Runtime) instead of the OpenJRE.</para>
|
|||
|
|
|
|||
|
|
</section>
|
|||
|
|
|