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-rw-r--r--doc/languages-frameworks/java.xml77
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diff --git a/doc/languages-frameworks/java.xml b/doc/languages-frameworks/java.xml
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@@ -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>