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Diffstat (limited to 'doc/languages-frameworks/java.xml')
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diff --git a/doc/languages-frameworks/java.xml b/doc/languages-frameworks/java.xml deleted file mode 100644 index 881d492b5bff..000000000000 --- a/doc/languages-frameworks/java.xml +++ /dev/null @@ -1,77 +0,0 @@ -<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 { ... }; - - nativeBuildInputs = [ jdk ant ]; - - buildPhase = "ant"; -} -</programlisting> - Note that <varname>jdk</varname> is an alias for the OpenJDK (self-built where available, or pre-built via Zulu). Platforms with OpenJDK not (yet) in Nixpkgs (<literal>Aarch32</literal>, <literal>Aarch64</literal>) point to the (unfree) <literal>oraclejdk</literal>. - </para> - - <para> - JAR files that are intended to be used by other packages should be installed in <filename>$out/share/java</filename>. JDKs have a stdenv setup hook that add any JARs in the <filename>share/java</filename> directories of the build inputs to the <envar>CLASSPATH</envar> environment variable. For instance, if the package <literal>libfoo</literal> installs a JAR named <filename>foo.jar</filename> in its <filename>share/java</filename> directory, and another package declares the attribute -<programlisting> -buildInputs = [ libfoo ]; -nativeBuildInputs = [ jdk ]; -</programlisting> - then <envar>CLASSPATH</envar> will be set to <filename>/nix/store/...-libfoo/share/java/foo.jar</filename>. - </para> - - <para> - Private JARs should be installed in a location like <filename>$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 a JRE. You can use <literal>makeWrapper</literal> for this: -<programlisting> -nativeBuildInputs = [ 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> -Since the introduction of the Java Platform Module System in Java 9, Java distributions typically no longer ship with a general-purpose JRE: instead, they allow generating a JRE with only the modules required for your application(s). Because we can't predict what modules will be needed on a general-purpose system, the default <package>jre</package> package is the full JDK. When building a minimal system/image, you can override the <literal>modules</literal> parameter on <literal>jre_minimal</literal> to build a JRE with only the modules relevant for you: -<programlisting> -let - my_jre = pkgs.jre_minimal.override { - modules = [ - # The modules used by 'something' and 'other' combined: - "java.base" - "java.logging" - ]; - }; - something = (pkgs.something.override { jre = my_jre; }); - other = (pkgs.other.override { jre = my_jre; }); -in - ... -</programlisting> - </para> - - <para> - Note all JDKs passthru <literal>home</literal>, so if your application requires environment variables like <envar>JAVA_HOME</envar> being set, that can be done in a generic fashion with the <literal>--set</literal> argument of <literal>makeWrapper</literal>: -<programlisting> ---set JAVA_HOME ${jdk.home} -</programlisting> - </para> - - <para> - It is possible to use a different Java compiler than <command>javac</command> from the OpenJDK. For instance, to use the GNU Java Compiler: -<programlisting> -nativeBuildInputs = [ gcj ant ]; -</programlisting> - Here, Ant will automatically use <command>gij</command> (the GNU Java Runtime) instead of the OpenJRE. - </para> -</section> |