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These guidelines are laid out in order of relevance to packaging.




== Introduction ==
This page represents Fedora guidelines for packaging libraries and applications written in Java and related languages using Java Virtual Machine as bytecode interpreter. It '''DOES NOT''' aim to extensively describe packaging techniques and tips. RPM macros and commands used here are documented in man pages. Furthermore a separate [https://fedorahosted.org/released/javapackages/doc/ Java Packaging HOWTO] describes Java packaging techniques in detail and includes examples, templates and documentation aimed at packagers and Java developers who are taking their first steps in Java RPM packaging.


These guidelines are laid out in order of relevance to packaging.
Fedora Java packaging is originally based on [http://www.jpackage.org JPackage Project] standards. Over time we have diverged in packaging tools in most areas but we mostly keep backward compatibility with older packages that make use of JPackage standards.


== Introduction ==


=== The Basics ===
== Package naming ==
The term Java means many things to many people:  a class library, a bytecode interpreter, a JIT compiler, a language specification, etc.  For the vast majority of users and developers, Java is a programming language and runtime environment that is architecture- and OS-agnostic.  The normal flow of code is <code>.java</code> (source file) <code>.class</code> (Java bytecode) <code>.jar</code> (a zip archive).  In the majority of cases, a user executes a Java program by specifying a class name containing a main method (just like C and C++).  Often, this is done by invoking the <code>java</code> binary with a list of JAR files specifying the classpath like so:


<code>java [-cp <jar1:jar2:jar3>] <main-class> [<args>] </code>
Packages '''MUST''' follow the standard Fedora [[Packaging/NamingGuidelines | package naming guidelines]].


== Java Packaging ==
Java API documentation '''MUST''' be placed into a sub-package called <code>%{name}-javadoc</code>.
The [http://www.jpackage.org JPackage Project]  has defined standard file system locations and conventions for use in Java packages.  Many distributions have inherited these conventions and in the vast majority of cases, Fedora follows them verbatim.  We include relevant sections of the JPackage guidelines here but caution that the canonical document will always reside upstream:  [http://www.jpackage.org/cgi-bin/viewvc.cgi/src/jpackage-utils/doc/jpackage-1.5-policy.xhtml?revision=HEAD&root=jpackage JPackage Guidelines]  .  Over time, we would like to remove any divergences in these documents, but where they are different, these Fedora guidelines will take precedence for Fedora packages.


TODO: Find the proper jpackage link and fix it.
== Release tags ==
Packages '''MUST''' follow the standard Fedora [[Packaging/NamingGuidelines#Package_Versioning | package versioning guidelines]].


=== Package naming ===
== Pre-built dependencies ==
Packages '''MUST''' follow the standard Fedora [[Packaging:Guidelines#No_inclusion_of_pre-built_binaries_or_libraries | dependency bundling guidelines]].


Packages '''MUST''' follow the standard Fedora [[Packaging/NamingGuidelines]].
In particular <code>*.class</code> and <code>*.jar</code> files from upstream releases '''MUST NOT''' be used during build of Fedora packages and they '''MUST NOT''' be included in binary RPM.


Java API documentation '''MUST''' be placed into a sub-package called <code>%{name}-javadoc</code>.
== JAR file installation ==


==== Release tags ====
The following applies to all JAR files except [[#JNI|JNI-using JAR files]] and application-specific JAR files (ie. JAR files that can only reasonably be used as part of an application and therefore constitute application-private data).
Packages '''MUST''' follow the standard Fedora [[Packaging/NamingGuidelines#Package_Version | Package versioning guidelines]].


=== JAR file installation ===
=== Split JAR files ===


The following applies to all JAR files except [[#JNI|JNI-using JAR files]], [[#GCJ|GCJ files]] and application-specific JAR files (ie. JAR files that can only reasonably be used as part of an application and therefore constitute application-private data).
If a project offers the choice of packaging it as a single monolithic JAR or several ones, the split packaging '''SHOULD''' be preferred.


==== Split JAR files ====
=== Installation directory ===


If a project offers the choice of packaging it as a single monolithic jar or several ones, the split packaging '''should''' be preferred.
* All architecture-independent JAR files '''MUST''' go into <code>%{_javadir}</code> or its subdirectory.


==== Filenames ====
* For installation of architecture dependent JAR files, see [[#Packaging_JAR_files_that_use_JNI|Packaging JAR files that use JNI]].


* If the package provides a '''single''' JAR and the filename provided by the build is <code>%{name}.jar</code> or <code>%{name}-%{version}.jar</code> then filename <code>%{name}.jar</code> '''MUST''' be used.
=== Filenames ===
* If the package provides a '''single''' JAR and the filename provided by the build is neither <code>%{name}-%{version}.jar</code> nor <code>%{name}.jar</code> then this file '''MUST''' be installed as <code>%{name}.jar</code> and a symbolic link with the usual name must be provided. Alternatively, the file can be installed to the subdirectory <code>%{_javadir}/%{name}/</code>.
* If the package provides more than '''one''' JAR file, the filenames assigned by the build '''MUST''' be used (without versions).
* If the project usually provides alternative JAR file names by installing symbolic links then such symlinks '''MAY''' be installed in the same directory as the JAR files.


{{admon/note|Note|Here %{name} refers either to package name, or name of subpackage where the jar is installed.}}
* If the package provides a '''single''' JAR file installed filename '''SHOULD''' be <code>%{name}.jar</code>.
* If the package provides '''multiple''' JAR file, files '''SHOULD''' be installed in a <code>%{name}</code> subdirectory
* Versioned JAR files (<code>*-%{version}.jar</code>) '''MUST NOT''' be installed unless the package is a compatibility package
* Packages '''CAN''' provide alternative filenames as long as they do not conflict with other packages


==== Installation directory ====


* All architecture-independent JAR files '''MUST''' go into <code>%{_javadir}</code> or a Java-version specific directory <code>%{_javadir}-<i>*</i></code> as appropriate[http://lists.fedoraproject.org/pipermail/packaging/2010-January/006792.html]. Packages '''CAN''' place JAR files into subdirectories.
{{admon/note|Note|Here %{name} refers either to package name, or name of subpackage where the jar is installed.}}


* For installation of architecture dependent jar files, see [[#Packaging_JAR_files_that_use_JNI|Packaging JAR files that use JNI]]
== BuildRequires and Requires ==
Java packages '''MUST''' BuildRequire their respective build system:
* <code>BuildRequires: maven-local</code> for packages built with Maven
* <code>BuildRequires: ant</code> for packages built with ant
* <code>BuildRequires: java-devel</code> for packages built with javac


=== Compatibility packages ===
Java binary packages or their dependencies '''MUST''' have Requires (generated by RPM or manual) on:
In certain cases it might be necessary to create compatibility packages that provide older API/ABI level of the same library. However creating these compatibility packages is strongly discouraged. To standardize and simplify packaging of such compatibility packages following rules apply:
* <code>java-headless</code> or <code>java-headless >= 1:minimal_required_version</code>
* <code>jpackage-utils</code>


* Compatibility packages are named in the same way as original except addition of version to package name
If java-headless requirement is insufficient package '''MUST''' have Requires:
* Jar and pom files '''MUST''' be versioned
* <code>java</code> or <code>java >= 1:minimal_required_version</code>


{{admon/note|Ant and Maven compatibility|build-classpath and related tools will resolve versioned jar files if versioned jar is asked for. Maven will use dependency information from main package and will return versioned jar if it matches the version asked for in the pom file.}}
== Javadoc installation ==


=== Javadoc installation ===
* javadoc documentation '''CAN''' be generated
 
* If javadoc documentation is generated it '''MUST''' be installed into a directory of <code>%{_javadocdir}/%{name}</code> as part of javadoc subpackage
* Java API documentation uses a system known as javadoc.  All javadocs '''MUST''' be created and installed into a directory of <code>%{_javadocdir}/%{name}</code>.
* Directory or symlink <code>%{_javadocdir}/%{name}-%{version}</code> '''SHOULD NOT''' exist.
* Directory or symlink <code>%{_javadocdir}/%{name}-%{version}</code> '''SHOULD NOT''' exist.
* The javadoc subpackage '''MUST''' be declared <code>noarch</code> even if main package is architecture specific.
* The javadoc subpackage '''MUST''' be declared <code>noarch</code> even if main package is architecture specific.


=== BuildRequires and Requires ===
== No class-path in MANIFEST.MF ==
At a minimum, Java packages '''MUST''':
* JAR files '''MUST NOT''' include <code>classh-path</code> entry inside META-INF/MANIFEST.MF


<pre>BuildRequires: java-devel [>= specific_version]
== Hardcoded paths ==
BuildRequires: jpackage-utils
Packages '''MUST NOT''' hardcode paths to JAR files they use. When package needs to reference a JAR file, packager '''SHOULD''' use one of tools designed to locating JAR files in the system.


Requires:  java [>= specific_version]
== Maven pom.xml files ==
Requires:  jpackage-utils</pre>
If upstream project is shipping Maven <code>pom.xml</code> files, these '''MUST''' be installed. Additionally package '''MUST''' install mapping between upstream artifact and filesystem by using either <code>%mvn_install</code> or <code>%add_maven_depmap</code> macros.


For historical reasons, when specifying versions 1.6.0 or greater, an epoch of 1 must be included.  Example:
{{admon/note|Additional documentation|Usage of %add_maven_depmap macro is documented in detail in [https://fedorahosted.org/released/javapackages/doc/#_add_maven_depmap_macro Java Packaging HOWTO].}}


<pre>Requires: java >= 1:1.6.0
</pre>


=== build-classpath ===
If upstream project does not ship Maven <code>pom.xml</code> file, official [http://mvnrepository.com/ maven repository] should be searched and if there are <code>pom.xml</code> files they '''SHOULD''' be installed.
<code>build-classpath</code> is a script that can be used to generate classpaths from generic names of JAR files. Example:


<pre>export CLASSPATH=$(build-classpath commons-logging commons-net xbean/xbean-reflect)
If modifications to Maven pom.xml files are needed <code>%pom_*</code> family of macros '''SHOULD''' be used
</pre>
{{admon/note|Additional information|You can use either jar filename or directory name relative to %{_javadir}, %{_jnidir} or %{_javajnidir} (all jar files will be included).}}


=== build-jar-repository ===
{{admon/note|Additional documentation|Usage of %pom_* macros is documented in detail in [https://fedorahosted.org/released/javapackages/doc/#helper_macros Java Packaging HOWTO].}}
<code>build-jar-repository</code> is similar to <code>build-classpath</code> but instead of producing a classpath entry, it creates symlinks in a given directory.  Example:
<pre>$ mkdir lib
$ build-jar-repository -s -p lib commons-logging commons-net
$ ls -l lib
commons-logging.jar -> /usr/share/java/commons-logging.jar
commons-net.jar -> /usr/share/java/commons-net.jar
</pre>


=== ant ===
== Wrapper Scripts ==
<code>ant</code> is a build tool used by many Java packages. Packages built using <code>ant</code> ship with <code>build.xml</code> files which contain build targets similar to <code>Makefiles</code>. Packages built using <code>ant</code> must:
Applications wishing to provide a convenient method of execution '''SHOULD''' provide a wrapper script in <code>%{_bindir}</code>. Packages '''SHOULD''' use <code>%jpackage_script</code> to create these wrapper scripts.


<pre>BuildRequires: ant
{{admon/note|Additional documentation|Usage of %jpackage_script macro is documented in [https://fedorahosted.org/released/javapackages/doc/#_generating_application_shell_scripts Java Packaging HOWTO].}}
...
%build
...
ant
</pre>


=== Maven pom.xml files and depmaps ===
== Compatibility packages ==
If upstream project is shipping Maven <code>pom.xml</code> files, these '''MUST''' be installed. Additionally they '''MUST''' install corresponding depmaps.
In certain cases it might be necessary to create compatibility packages that provide older API/ABI level of the same library. However creating these compatibility packages is strongly discouraged. To standardize and simplify packaging of such compatibility packages following rules apply:
 
If upstream project does not ship pom.xml file [[http://repo1.maven.org/maven2/ official maven repo]] should be checked and if there are pom.xml files they '''SHOULD''' be installed.
 
{{admon/tip|Tip|[http://mvnrepository.com/ Mvnrepository site] can be used to ease}}
 
=== add_maven_depmap macro ===
{{Anchor|depmap_macro}}
 
This macro '''SHOULD''' only be used by packages which don't use Maven to build.
 
Maven identifies jar files by a set of strings: groupId, artifactId and version (mostly). To let mvn-rpmbuild know what groupId:artifactId corresponds to which pom or jar file, we use the <code>%add_maven_depmap</code> macro. <code>%add_maven_depmap</code> reads the groupId and artifactId from the pom file and creates a file in <code>%{_mavendepmapfragdir}</code> that maps groupId:artifactId pairs to jar files under <code>%{_javadir}</code>. All fragments in this directory are read by mvn-rpmbuild during startup, allowing the locally installed jar files and poms to be used as a maven repository.
 
Note that -- unless you use the <code>-f</code> option as shown below -- all depmap fragments for a given package are written to the same file, <code>%{_mavendepmapfragdir}/%{name}</code>. You should be sure to include this file in the <code>%files</code> section of your RPM.
 
For the macro to work properly, all jar files must be copied into <code>%{_javadir}</code> (see [[#JAR_file_installation|JAR file installation]]), and all pom files must be copied into <code>%{_mavenpomdir}</code> and given file names of the following form, where <code>jarname</code> is the name of the jar without the .jar suffix:
<pre>%{_mavenpomdir}/JPP[.subdirectory]-jarname.pom</pre>
Note that the subdirectory is only necessary if the jar file is put into a subdirectory of <code>%{_javadir}</code>. For example:
* For junit, the jar is <code>%{_javadir}/junit.jar</code>, so the pom would be <code>%{_mavenpomdir}/JPP-junit.pom</code>.
* For plexus-ant-factory, the jar is <code>%{_javadir}/plexus/ant-factory.jar</code>, so the pom would named <code>%{_mavenpomdir}/JPP.plexus-ant-factory.pom</code>.
If a pom is installed with no corresponding jar file -- for example, for parent poms -- the same convention should be followed:
* The Apache commons parent pom is installed in <code>%{_mavenpomdir}/JPP-commons-parent.pom</code>.
 
In its simplest form (a pom without a jar file), <code>%add_maven_depmap</code> looks like this:
<pre>%add_maven_depmap JPP-%{name}.pom</pre>
This will read the pom file in question and provide a mapping between the groupId and artifactId inside the pom file and the pom file placed into <code>%{_mavenpomdir}</code>.
 
For a pom that maps directly to a jar file, the following is the correct form:
<pre>%add_maven_depmap JPP-%{name}.pom %{name}.jar</pre>
In addition to creating the pom mapping, this will also ensure that the correct jar is associated with the groupId and artifactId from the pom.
 
<pre>%add_maven_depmap JPP-%{name}.pom %{name}.jar -a "org.apache.commons:commons-lang"</pre>
This form also adds additional mappings for given pom/jar file. For example, if the pom file indicates that it contains groupId commons-lang, artifactId commons-lang, this form ensures that we also add a mapping between groupId org.apache.commons and the installed jar/pom files. This is necessary in cases where the groupId or artifactId may have changed, and other packages might require different IDs than those reflected in the installed pom.
 
<pre>%add_maven_depmap JPP-%{name}.pom %{name}.jar -f "XXX"</pre>
This form stores dependency mapping inside <code>%{_mavendepmapfragdir}/%{name}-XXX</code> instead of standard location. This is useful for packages with multiple subpackages where each has its own jar files.
 
<pre>%add_maven_depmap JPP.%{name}-sub.pom %{name}/sub.jar</pre>
This form should be used when a package consists of multiple jar files that are installed into a subdirectory of <code>%{_javadir}</code>. Note that in this case, the pom file name includes the optional subdirectory field.
 
=== Apache Maven ===
In Fedora 15 and newer, Maven 3 is used. Packages built using Maven ship with <code>pom.xml</code> files. They '''SHOULD''' contain common sections such as the following:
 
<pre>
BuildRequires:  maven-local
...
%build
%mvn_build
...
 
%install
%mvn_install
...
 
 
%files -f .mfiles
</pre>
 
The macros <code>%mvn_build</code> and <code>%mvn_install</code> automatically handle building of the JAR files and their subsequent installation to the correct directory. The corresponding POM and depmap files are also installed.
 
==== Additional mappings ====
{{Anchor|pom_jar_mapping}}
 
The macro <code>%mvn_alias</code> can be used to add additional mappings for given POM/JAR file. For example, if the POM file indicates that it contains groupId commons-lang, artifactId commons-lang, this macro ensures that we also add a mapping between groupId org.apache.commons and the installed JAR/POM files. This is necessary in cases where the groupId or artifactId may have changed, and other packages might require different IDs than those reflected in the installed POM.
 
<pre>%mvn_alias "commons-lang:commons-lang" "org.apache.commons:commons-lang"</pre>
 
==== Alternative JAR file names ====
In some cases, it may be important to be able to provide symlinks to actual JAR files. This can be achieved with <code>%mvn_file</code> macro. This macro allows packager to specify names of the JAR files, their location in <code>%{_javadir}</code> directory and also can create symlinks to the JAR files. These symlinks can be possibly located outside of the <code>%{_javadir}</code> directory.
 
Example of usage of <code>%mvn_file</code> macro:
 
<pre>
%prep
...
%mvn_file :guice google/guice guice
</pre>
 
This means that JAR file for artifact with ID "guice" (and any groupId) will be installed in <code>%{_javadir}/google/guice.jar</code> and there also will be a symlink to this JAR file located in <code>%{_javadir}/guice.jar</code>. Note the macro will add ".jar" extensions automatically.
 
==== Single artifact per package ====
If the project consists of multiple artifacts, it is recommended to install each artifact to the separate subpackage. The macro <code>%mvn_build -s</code> will generate separate <code>.mfiles</code> file for every artifact in the project. This file contains list of files related to specific artifact (typically JAR file, POM file and depmap). It can be later used in <code>%files</code> section of the spec file.
 
Example:
<pre>
...
%description
The Maven Plugin Tools contains...
 
%package -n maven-plugin-annotations
Summary:        Maven Plugin Java 5 Annotations
 
%description -n maven-plugin-annotations
This package contains Java 5 annotations to use in Mojos.
 
%package -n maven-plugin-plugin
Summary:        Maven Plugin Plugin
 
%description -n maven-plugin-plugin
The Plugin Plugin is used to...
...
 
%build
%mvn_build -s
 
%install
%mvn_install
 
%files -f .mfiles-maven-plugin-tools
%doc LICENSE NOTICE
%files -n maven-plugin-annotations -f .mfiles-maven-plugin-annotations
%files -n maven-plugin-plugin      -f .mfiles-maven-plugin-plugin
%files -f .mfiles-javadoc
...
</pre>
 
==== Assigning Maven artifacts to the subpackages ====
The package layout can be customized with <code>%mvn_package</code> macro. This macro allows maintainer to specify exact package in which the selected artifact will end up.
 
Example:
<pre>
...
%prep
%mvn_package ":plexus-compiler-jikes"  plexus-compiler-extras
%mvn_package ":plexus-compiler-eclipse" plexus-compiler-extras
%mvn_package ":plexus-compiler-csharp"  plexus-compiler-extras
 
%build
%mvn_build
 
%mvn_install
 
%files -f .mfiles
%files -f .mfiles-plexus-compiler-extras
%files -f .mfiles-javadoc
</pre>
 
In above example, the artifacts <code>plexus-compiler-jikes</code>, <code>plexus-compiler-eclipse</code>, <code>plexus-compiler-csharp</code> will end up in package named <code>plexus-compiler-extras</code>. If there are some other artifacts beside these three mentioned (e.g. some parent POMs), then these will all end up in package named <code>%{name}</code>.
 
{{admon/tip|Tip|<code>%mvn_package</code> macro supports brace expansions, so whole <code>%prep</code> section from previous example can be replaced with single line:
<code>%mvn_package ":plexus-compiler-{jikes,eclipse,csharp}" plexus-compiler-extras</code> }}
 
=== Patching Maven <code>pom.xml</code> files ===
 
Sometimes Maven <code>pom.xml</code> files need to be patched before they are used to build packages. One could use traditional patches to maintain changes, but package maintainers '''SHOULD''' use <code>%pom_*</code> macros developed specially to ease this task.
 
These macros are designed to be called from <code>%prep</code> section of spec files. There are documented in <code>/etc/rpm/macros.fjava</code> configuration file, which is also [http://git.fedorahosted.org/git/?p=javapackages.git;a=blob_plain;f=macros.fjava available online]. See the documentation for technical details how to use these macros. Below are some examples added for convenience.
 
Often dependencies specified in Maven <code>pom.xml</code> files need to be removed because of different reasons. <code>%pom_remove_dep</code> macro can be used to ease this task:
 
<pre>
# Removes dependency on groupId:artifactId from ./pom.xml
%pom_remove_dep groupId:artifactId
 
# Removes dependency on groupId:artifactId from ./submodule/pom.xml
%pom_remove_dep groupId:artifactId submodule
 
# Removes dependency on groupId:artifactId from ./full/path/to/file.pom
%pom_remove_dep groupId:artifactId full/path/to/file.pom
 
# Removes dependency on all artifacts in group groupId from ./pom.xml
%pom_remove_dep groupId:
 
# Removes all dependencies from ./pom.xml
%pom_remove_dep :
</pre>
 
<code>%pom_remove_plugin</code> macro works exactly as <code>%pom_remove_dep</code>, except it removes Maven plugin invocations. Some examples:
 
<pre>
# Disables maven-jar-plugin so that classpath isn't included in manifests
%pom_remove_plugin :maven-jar-plugin
 
# Disable a proprietary plugin that isn't packaged for Fedora
%pom_remove_plugin com.example.mammon:useless-proprietary-plugin submodule
</pre>
 
Sometimes some submodules of upstream project cannot be built for various reasons and there is a need to disable them. This can be achieved by using <code>%pom_disable_module</code>, for example:
 
<pre>
# Disables child-module-1, a submodule of the main pom.xml file
%pom_disable_module child-module-1
 
# Disables grandchild-module, a submodule of child-module-2/pom.xml
%pom_disable_module grandchild-module child-module-2
</pre>
 
The above macros cover the most common cases of modifying <code>pom.xml</code> files, however if there is a need to apply some less-common patches there are also two generic macros for modifying <code>pom.xml</code> files. <code>%pom_xpath_remove</code> can be used to remove arbitrary XML nodes, described by [http://www.w3.org/TR/xpath/ XPath] expressions. <code>%pom_xpath_inject</code> macro is capable of injecting arbitrary [http://www.w3.org/TR/xml/ XML] code to any <code>pom.xml</code> file. Below you can find some examples for these macros.
 
<pre>
# Removes parent definition
%pom_xpath_remove "pom:parent"
 
# Removes extensions from the build
%pom_xpath_remove "pom:build/pom:extensions" module/pom.xml
 
# Adds new dependency
%pom_xpath_inject "pom:dependencies" "<dependency><groupId>org.example.project</groupId><artifactId>awesomeproject</artifactId><version>1.0.0.GA</version></dependency>"
</pre>
 
{{admon/note|Note|POM files use a specific namespace - http://maven.apache.org/POM/4.0.0. The easiest way to respect this namespace in XPath expressions is prefixing all node names with <code>pom:</code>. For example, <code>pom:environment/pom:os</code> will work because it selects nodes from <code>pom</code> namespace, but <code>environment/os</code> won't find anything because it looks for nodes that don't belong to any XML namespace.}}
 
Using <code>%pom_*</code> macros not only increases readability of the spec file, but also improves maintainability of the package as there are no patches that would need to be rebased with each upstream release.
 
=== Wrapper Scripts ===
Applications wishing to provide a convenient method of execution '''SHOULD''' provide a wrapper script in <code>%{_bindir}</code>. 
 
The jpackage-utils package contains a convenience <code>%jpackage_script</code> macro that can be used to create scripts that work for the majority of packages.  See its definition and documentation in <code>/etc/rpm/macros.jpackage</code>.  One thing to pay attention to is the 6th argument to it - whether to prefer a JRE over a full SDK when looking up a JVM to invoke - most packages that don't require the full Java SDK will want to set that to <code>true</code> to avoid unexpected results when looking up a JVM when some of the installed JRE's don't have the corresponding SDK (*-devel package) installed.
 
<pre>
%install
...
%jpackage_script com.sun.msv.driver.textui.Driver "" "" msv-msv:msv-xsdlib:relaxngDatatype:isorelax msv true
...
</pre>
The previous example installs the "msv" script (5th argument) with main class being com.sun.msv.driver.textui.Driver (1st argument). No optional flags (2nd argument) or options (3rd argument) are used. This script will add several libraries to classpath before executing main class (4th argument, jars separated with ":"). <code>build-classpath</code> is run on every part of 4th argument to create full classpaths.
 
=== GCJ ===
Building GCJ AOT bits is discouraged unless you have a very strong reason to include them in the packages.
Even when AOT bits are built and included in packages it is recommended to not require java-1.5.0-gcj because this will force every single user to install it even if one wants to use another JVM.
 
Please refer to [[Packaging/GCJGuidelines]]  for GCJ-specific guidelines.
 
=== -devel packages ===
<code>-devel</code> packages don't really make sense for Java packages.  Header files do not exist for Java packages.
 
== Specfile Template ==
=== ant ===
 
<pre>
Name:          # see normal package guidelines
Version:        # see normal package guidelines
Release:        1%{?dist}
Summary:        # see normal package guidelines
 
Group:          # see normal package guidelines
License:        # see normal package guidelines
URL:            # see normal package guidelines
Source0:        # see normal package guidelines
BuildArch:      noarch
 
BuildRequires:  jpackage-utils
 
BuildRequires:  java-devel
 
BuildRequires:  ant
 
Requires:      jpackage-utils
 
Requires:      java
 
%description
 
%package javadoc
Summary:        Javadocs for %{name}
Group:          Documentation
Requires:      jpackage-utils
 
%description javadoc
This package contains the API documentation for %{name}.
 
%prep
%setup -q
 
find -name '*.class' -exec rm -f '{}' \;
find -name '*.jar' -exec rm -f '{}' \;
 
%build
ant
 
%install
 
mkdir -p $RPM_BUILD_ROOT%{_javadir}
cp -p [build path to jar] $RPM_BUILD_ROOT%{_javadir}/%{name}.jar
 
mkdir -p $RPM_BUILD_ROOT%{_javadocdir}/%{name}
cp -rp [javadoc directory] $RPM_BUILD_ROOT%{_javadocdir}/%{name}
 
%files
%{_javadir}/*
%doc
 
%files javadoc
%{_javadocdir}/%{name}
 
 
%changelog
</pre>
 
 
 
=== Apache Maven ===
<pre>
Name:          # see normal package guidelines
Version:        # see normal package guidelines
Release:        1%{?dist}
Summary:        # see normal package guidelines
 
License:        # see normal package guidelines
URL:            # see normal package guidelines
Source0:        # see normal package guidelines
BuildArch:      noarch
 
BuildRequires:  java-devel [>= java version]
BuildRequires:  maven-local
 
%description
some smart and long description.
 
%package javadoc
Summary:        API documentation for %{name}
 
%description javadoc
This package contains %{symmary}.
 
%prep
%setup -q
 
%build
%mvn_build
 
%install
%mvn_install
 
%files -f .mfiles
%doc
 
%files javadoc -f .mfiles-javadoc
%doc
 
%changelog
 
</pre>
 
== Packaging and using EE APIs ==
There are a number of various project providing implementations for Java EE APIs. To simplify packaging and use of these APIs certain standardization is necessary.
 
=== EE API List ===
Following is a list of EE APIs as of Java EE 6[http://docs.oracle.com/javaee/6/api/] with chosen packages that provide implementations:
* javax.activation - JDK
* javax.annotation - JDK
* javax.el - tomcat-el-2.2-api
* javax.enterprise.inject - cdi-api
* javax.inject - atinject
* javax.jws - JDK
* javax.mail - javamail 
* javax.management - JDK
* javax.management.remote - JDK
* javax.persistence - geronimo-jpa
* javax.security.auth.message - geronimo-jaspic-spec
* javax.servlet - tomcat-servlet-3.0-api
* javax.servlet.jsp - glassfish-jsp/glassfish-jsp-api
* javax.servlet.jsp.jstl - jakarta-taglibs-standard
* javax.transaction - JDK
* javax.ws.rs - jsr-311
* javax.wsdl - wsdl4j
* javax.xml - JDK
* javax.xml.bind - JDK
* javax.xml.rpc - axis
* javax.xml.soap - JDK
* javax.xml.stream - JDK
* javax.xml.ws - JDK
 
=== Packages providing APIs ===
In addition to following generic guidelines they '''MUST''':
* Add '''Provides: javax.XXX''' from the [[#EE_API_List|EE API list]]
* Add directory %{_javadir}/javax.XXX that will contain symlinks to all implementation jar files and their dependencies
 
At one time there '''CAN BE''' multiple API implementations but there '''MUST''' be at most one package having specific '''javax.XXX''' virtual provide.


=== Packages using APIs ===
* Compatibility packages '''MUST''' be named in the same way as original except addition of version to package name,
Packages that need to use EE API '''SHOULD''' use:
* Any JAR and POM files '''MUST''' be versioned.
* '''Requires: javax.XXX''' from the [[#EE_API_List|EE API list]]
* '''build-classpath javax.XXX''' or equivalent instead of relying on package-specific jar name.


{{admon/note|Ant and Maven compatibility|build-classpath and related tools will resolve versioned jar files if versioned jar is asked for. Maven will use dependency information will return versioned jar if it matches the version asked for in the pom file.}}


== Packaging JAR files that use JNI ==
== Packaging JAR files that use JNI ==
Line 493: Line 111:
* JNI shared objects '''MUST''' be placed in <code>%{_libdir}/%{name}</code>  
* JNI shared objects '''MUST''' be placed in <code>%{_libdir}/%{name}</code>  


{{admon/note|Note|If the JNI-using code calls <code>System.loadLibrary</code> you'll have to patch it to use <code>System.load</code>, passing it the full path to the dynamic shared object.}}
{{admon/note|Note|If the JNI-using code calls <code>System.loadLibrary</code> you'll have to patch it to use <code>System.load</code>, passing it the full path to the dynamic shared object. You can look at the [[JavaSystemLoadExample|example]].}}
 
{{admon/note|Macro expansions|<code>%{_jnidir}</code> usually expands into <code>%{_prefix}/lib/java</code>. <code>%{_prefix}/lib64/java</code> will cease its existence and will be decomissioned}}
 
=== Example ===
To satisfy this Fedora requirement of using "System.load()" instead of "System.loadLibrary()" while still providing 32-bit versus 64-bit usability as well as complying with Java's write-once-run-anywhere goal, most JNI jar file should contain code similar to the following (as used in the pki-symkey JNI package):
<pre>
    static boolean tryLoad(String filename) {
        try {
            System.load(filename);
        } catch (Exception e) {
            return false;
        } catch (UnsatisfiedLinkError e) {
            return false;
        }
 
        return true;
    }
 
    // Load native library
    static {
        boolean mNativeLibrariesLoaded = false;
        String os = System.getProperty("os.name");
        if ((os.equals("Linux"))) {
            // Check for 64-bit library availability
            // prior to 32-bit library availability.
            mNativeLibrariesLoaded =
                    tryLoad("/usr/lib64/symkey/libsymkey.so");
            if (mNativeLibrariesLoaded) {
                System.out.println("64-bit symkey library loaded");
            } else {
                // REMINDER:  May be trying to run a 32-bit app
                //            on 64-bit platform.
                mNativeLibrariesLoaded =
                        tryLoad("/usr/lib/symkey/libsymkey.so");
                if (mNativeLibrariesLoaded) {
                    System.out.println("32-bit symkey library loaded");
                } else {
                    System.out.println("FAILED loading symkey library!");
                    System.exit(-1);
                }
            }
        } else {
            try {
                System.loadLibrary("symkey");
                System.out.println("symkey library loaded");
                mNativeLibrariesLoaded = true;
            } catch (Throwable t) {
                // This is bad news, the program is doomed at this point
                t.printStackTrace();
            }
        }
    }
</pre>
 
Packages utilizing approach of bundling so files as resources within JAR files themselves do not have these issues and are more self-contained.
 
=== Notes on multiarch ===
 
Our guidelines have never been completely multiarch-aware. So it was never really possible to install both i686 and x86_64 JNI-using java libraries. However guidelines complicated things by introducing usage of %{_libdir} and other directories. This version makes it clear we do not support multiarch for JNI-using packages.
 
Some of the complications with multiarch for JNI packages are:
* build-classpath and related tools would need to be aware what will be architecture of executing JVM
* build-jar-classpath would still not work for creating symlinks because it would create them on build architecture instead of runtime architecture
* Previous reasons cause creating of /usr/bin wrappers impractical
* Handling proper requires in RPM is impossible. For example package Z-native.i686 and JDK.x86_64 are installed. As far as RPM is concerned this would be enough to provide Z.noarch with needed "Requires: Z-native", but it would not work during runtime.
 
== Things to avoid ==
=== Pre-built JAR files / Other bundled software ===
Many Java projects re-ship their dependencies in their own releases.  This is unacceptable in Fedora.  All packages '''MUST''' be built from source and '''MUST''' enumerate their dependencies with <code>Requires</code>.  They '''MUST NOT''' build against or re-ship the pre-included JAR files but instead symlink out to the JAR files provided by dependencies.  There may arise rare cases that an upstream project is distributing JAR files that are actually not re-distributable
by Fedora.  In this situation, the JAR files themselves should not be redistributed -- even in the source zip.  A modified source zip should be created with some sort of modifier in the name (ex. -CLEAN) along with instructions for reproducing.  It is a good idea to have something similar to the following at the end of <code>%prep</code> (courtesy David Walluck):
 
<pre>
JAR files=""
for j in $(find -name \*.jar); do
if [ ! -L $j ] ; then
JAR files="$JAR files $j"
fi
done
if [ ! -z "$JAR files" ] ; then
echo "These JAR files should be deleted and symlinked to system JAR files: $JAR files"
exit 1
fi
</pre>
 
=== Javadoc scriptlets ===
Older JPackage packages contained <code>%post</code> scriptlets creating <code>%ghost</code> symlinks.  These '''MUST''' not appear in Fedora Java packages and are actively being removed at JPackage.
 
=== Selected rpmlint issues ===
==== class-path-in-manifest ====
Use <code>sed</code> to remove <code>class-path</code> elements in <code>MANIFEST.MF</code> (or whatever file is being used as the JAR manifest) prior to JAR creation.  Example:
 
<pre>
sed -i '/class-path/I d' META-INF/MANIFEST.MF
</pre>
 
=== Older packaging techniques ===
If possible, the packagers '''MUST''' use new techniques described previously in this document. However, there are situations where those cannot be applied. For example, if older, but still supported Fedora release doesn't support the recommended macros, it is still possible to use older techniques of building and installing of JAR/POM files.
 
==== Maven 3 ====
From Fedora 15 to Fedora 18, maven 3 is used and the package is called <code>maven</code>.  Packages built using <code>maven</code> ship with <code>pom.xml</code> files.  They '''SHOULD''' contain common sections such as the following:
 
<pre>
...
%build
mvn-rpmbuild package javadoc:aggregate
...
 
%install
install -d -m 755 $RPM_BUILD_ROOT%{_javadir}
install -d -m 755 $RPM_BUILD_ROOT%{_mavenpomdir}
install -pm 644 pom.xml $RPM_BUILD_ROOT/%{_mavenpomdir}/JPP-%{name}.pom
install -pm 644 target/%{name}-%{version}.jar $RPM_BUILD_ROOT/%{_javadir}/%{name}.jar


# second argument is optional (parent poms have no jars)
{{admon/note|Macro expansions|<code>%{_jnidir}</code> expands into <code>%{_prefix}/lib/java</code>, even on 64-bit systems. Java packages using JNI do not support multiarch installation.}}
%add_maven_depmap JPP-%{name}.pom %{name}.jar
...


%check
mvn-rpmbuild verify


%files
%{_mavendepmapfragdir}/%{name}
%{_mavenpomdir}/JPP-%{name}.pom
</pre>


Useful mvn-rpmbuild customisations:
* -Dmaven.local.depmap.file=FILE.xml - xml file that defines alternative dependency maps
* -Dmaven.local.debug=true makes custom resolver output more debugging information


{{admon/important|Important|For detailed instructions on use of add_maven_depmap macro see [[#depmap_macro|macro documentation]]}}
[[Category:Java]]
[[Category:Packaging guidelines drafts]]

Latest revision as of 19:22, 14 October 2016

These guidelines are laid out in order of relevance to packaging.


Introduction

This page represents Fedora guidelines for packaging libraries and applications written in Java and related languages using Java Virtual Machine as bytecode interpreter. It DOES NOT aim to extensively describe packaging techniques and tips. RPM macros and commands used here are documented in man pages. Furthermore a separate Java Packaging HOWTO describes Java packaging techniques in detail and includes examples, templates and documentation aimed at packagers and Java developers who are taking their first steps in Java RPM packaging.

Fedora Java packaging is originally based on JPackage Project standards. Over time we have diverged in packaging tools in most areas but we mostly keep backward compatibility with older packages that make use of JPackage standards.


Package naming

Packages MUST follow the standard Fedora package naming guidelines.

Java API documentation MUST be placed into a sub-package called %{name}-javadoc.

Release tags

Packages MUST follow the standard Fedora package versioning guidelines.

Pre-built dependencies

Packages MUST follow the standard Fedora dependency bundling guidelines.

In particular *.class and *.jar files from upstream releases MUST NOT be used during build of Fedora packages and they MUST NOT be included in binary RPM.

JAR file installation

The following applies to all JAR files except JNI-using JAR files and application-specific JAR files (ie. JAR files that can only reasonably be used as part of an application and therefore constitute application-private data).

Split JAR files

If a project offers the choice of packaging it as a single monolithic JAR or several ones, the split packaging SHOULD be preferred.

Installation directory

  • All architecture-independent JAR files MUST go into %{_javadir} or its subdirectory.

Filenames

  • If the package provides a single JAR file installed filename SHOULD be %{name}.jar.
  • If the package provides multiple JAR file, files SHOULD be installed in a %{name} subdirectory
  • Versioned JAR files (*-%{version}.jar) MUST NOT be installed unless the package is a compatibility package
  • Packages CAN provide alternative filenames as long as they do not conflict with other packages


Note
Here %{name} refers either to package name, or name of subpackage where the jar is installed.

BuildRequires and Requires

Java packages MUST BuildRequire their respective build system:

  • BuildRequires: maven-local for packages built with Maven
  • BuildRequires: ant for packages built with ant
  • BuildRequires: java-devel for packages built with javac

Java binary packages or their dependencies MUST have Requires (generated by RPM or manual) on:

  • java-headless or java-headless >= 1:minimal_required_version
  • jpackage-utils

If java-headless requirement is insufficient package MUST have Requires:

  • java or java >= 1:minimal_required_version

Javadoc installation

  • javadoc documentation CAN be generated
  • If javadoc documentation is generated it MUST be installed into a directory of %{_javadocdir}/%{name} as part of javadoc subpackage
  • Directory or symlink %{_javadocdir}/%{name}-%{version} SHOULD NOT exist.
  • The javadoc subpackage MUST be declared noarch even if main package is architecture specific.

No class-path in MANIFEST.MF

  • JAR files MUST NOT include classh-path entry inside META-INF/MANIFEST.MF

Hardcoded paths

Packages MUST NOT hardcode paths to JAR files they use. When package needs to reference a JAR file, packager SHOULD use one of tools designed to locating JAR files in the system.

Maven pom.xml files

If upstream project is shipping Maven pom.xml files, these MUST be installed. Additionally package MUST install mapping between upstream artifact and filesystem by using either %mvn_install or %add_maven_depmap macros.

Additional documentation
Usage of %add_maven_depmap macro is documented in detail in Java Packaging HOWTO.


If upstream project does not ship Maven pom.xml file, official maven repository should be searched and if there are pom.xml files they SHOULD be installed.

If modifications to Maven pom.xml files are needed %pom_* family of macros SHOULD be used

Additional documentation
Usage of %pom_* macros is documented in detail in Java Packaging HOWTO.

Wrapper Scripts

Applications wishing to provide a convenient method of execution SHOULD provide a wrapper script in %{_bindir}. Packages SHOULD use %jpackage_script to create these wrapper scripts.

Additional documentation
Usage of %jpackage_script macro is documented in Java Packaging HOWTO.

Compatibility packages

In certain cases it might be necessary to create compatibility packages that provide older API/ABI level of the same library. However creating these compatibility packages is strongly discouraged. To standardize and simplify packaging of such compatibility packages following rules apply:

  • Compatibility packages MUST be named in the same way as original except addition of version to package name,
  • Any JAR and POM files MUST be versioned.
Ant and Maven compatibility
build-classpath and related tools will resolve versioned jar files if versioned jar is asked for. Maven will use dependency information will return versioned jar if it matches the version asked for in the pom file.

Packaging JAR files that use JNI

Applicability

Java programs that wish to make calls into native libraries do so via the Java Native Interface (JNI). A Java package uses JNI if it contains a .so file. Note that this file can be embedded within JAR files themselves.

Note that GCJ packages contain .sos in %{_libdir}/gcj/%{name} but they are not JNI .sos.

Guideline

  • JNI packages MUST follow guidelines of ordinary Java packages with exceptions listed here
  • JAR files using JNI or containing JNI shared objects themselves MUST be placed in %{_jnidir} and CAN BE symlinked to %{_libdir}/%{name}.
  • JNI shared objects MUST be placed in %{_libdir}/%{name}
Note
If the JNI-using code calls System.loadLibrary you'll have to patch it to use System.load, passing it the full path to the dynamic shared object. You can look at the example.
Macro expansions
%{_jnidir} expands into %{_prefix}/lib/java, even on 64-bit systems. Java packages using JNI do not support multiarch installation.
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