glfs/general/prog/java.xml
2023-11-02 00:57:56 -05:00

195 lines
6.7 KiB
XML

<?xml version="1.0" encoding="ISO-8859-1"?>
<!DOCTYPE sect1 PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
"http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd" [
<!ENTITY % general-entities SYSTEM "../../general.ent">
%general-entities;
<!-- Maintainer: before making the tarball, remove all .debuginfo files from
the directory: this saves more than 70 MB. -->
<!ENTITY anduin-download "&sources-anduin-http;/OpenJDK/OpenJDK-&openjdk-version;">
<!ENTITY openjdk-download-binary-x86 "&sources-anduin-http;/OpenJDK/OpenJDK-&openjdk-version;/OpenJDK-&openjdk-version;+&openjdk-build;-i686-bin.tar.xz">
<!ENTITY openjdk-bin-md5sum-x86 "d36dc78d9e27298e71766b2c23b673ec">
<!ENTITY openjdk-bin-size-x86 "161 MB">
<!ENTITY openjdk-bin-buildsize-x86 "314 MB">
<!-- Not uploaded to anduin, since this file is now available under GNU GPLv2
licence.-->
<!-- Reuploaded to anduin due to the complexity of the download URL, per Bruce's
request. - Doug -->
<!ENTITY openjdk-download-binary-x64 "&sources-anduin-http;/OpenJDK/OpenJDK-&openjdk-version;/OpenJDK-&openjdk-version;+&openjdk-build;-x86_64-bin.tar.xz">
<!ENTITY openjdk-bin-md5sum-x64 "d490971868549581475df007cae1ee6b">
<!ENTITY openjdk-bin-size-x64 "169 MB">
<!ENTITY openjdk-bin-buildsize-x64 "343 MB">
]>
<sect1 id="java" xreflabel="Java-&openjdk-version;">
<?dbhtml filename="java.html"?>
<title>Java-&openjdk-version;</title>
<indexterm zone="java">
<primary sortas="a-java">JDK Binary</primary>
</indexterm>
<sect2>
<title>About Java</title>
<para>
Java is different from most of the packages in LFS and BLFS. It
is a programming language that works with files of bytecode to obtain
instructions and executes them in a Java Virtual Machine (JVM). An
introductory java program looks like:
</para>
<screen><literal>public class HelloWorld
{
public static void main(String[] args)
{
System.out.println("Hello, World");
}
}</literal></screen>
<para>
This program is saved as <filename>HelloWorld.java</filename>. The
file name, <emphasis>HelloWorld</emphasis>, must match the class name.
It is then converted into byte code with
<command>javac HelloWorld.java</command>. The output file is
<filename>HelloWorld.class</filename>. The program is executed with
<command>java HelloWorld</command>. This creates a JVM and runs the
code. The 'class' extension must not be specified.
</para>
<para>
Several class files can be combined into one file with the
<command>jar</command> command. This is similar to the standard
<command>tar</command> command. For instance, the command
<command>jar cf myjar.jar *.class</command> will combine all class files
in a directory into one jar file. These act as library files.
</para>
<para>
The JVM can search for and use classes in jar files automatically.
It uses the <envar>CLASSPATH</envar> environment variable to search for
jar files. This is a standard list of colon-separated directory names
similar to the <envar>PATH</envar> environment variable.
</para>
</sect2>
<sect2 id="java-bin" xreflabel="Java Binary" role="package">
<title>Binary JDK Information</title>
<para>
Creating a JVM from source requires a set of circular dependencies.
The first thing that's needed is a set of programs called a Java
Development Kit (JDK). This set of programs includes
<command>java</command>, <command>javac</command>,
<command>jar</command>, and several others. It also includes several
base <emphasis>jar</emphasis> files.
</para>
<para>
To start, we set up a binary installation of the JDK created
by the BLFS editors. It is installed in the <filename>/opt</filename>
directory to allow for multiple installations, including a source based
version.
</para>
&lfs120_checked;
<bridgehead renderas="sect3">Binary Package Information</bridgehead>
<itemizedlist spacing="compact">
<listitem>
<para>
Binary download (x86): <ulink url="&openjdk-download-binary-x86;"/>
</para>
</listitem>
<listitem>
<para>
Download MD5 sum: &openjdk-bin-md5sum-x86;
</para>
</listitem>
<listitem>
<para>
Download size (binary): &openjdk-bin-size-x86;
</para>
</listitem>
<listitem>
<para>
Estimated disk space required: &openjdk-bin-buildsize-x86;
</para>
</listitem>
</itemizedlist>
<itemizedlist spacing="compact">
<listitem>
<para>
Binary download (x86_64): <ulink url="&openjdk-download-binary-x64;"/>
</para>
</listitem>
<listitem>
<para>
Download MD5 sum: &openjdk-bin-md5sum-x64;
</para>
</listitem>
<listitem>
<para>
Download size (binary): &openjdk-bin-size-x64;
</para>
</listitem>
<listitem>
<para>
Estimated disk space required: &openjdk-bin-buildsize-x64;
</para>
</listitem>
</itemizedlist>
<bridgehead renderas="sect3">Java Binary Runtime Dependencies</bridgehead>
<para role="required">
<xref role="runtime" linkend="alsa-lib"/>,
<xref role="runtime" linkend="cups"/>,
<xref role="runtime" linkend="giflib"/>, and
<xref role="runtime" linkend="xorg7-lib"/>
</para>
</sect2>
<sect2 role="installation">
<title>Installation of the Java BinaryJDK </title>
<!--
<note>
<para>
The tarball
<emphasis>openjdk-&openjdk-version;_linux-x64_bin.tar.gz</emphasis> will
untar to the <emphasis>jdk-&openjdk-version;</emphasis> directory.
</para>
</note>
-->
<para>
Begin by extracting the appropriate binary tarball for your
architecture and changing to the extracted directory. Install the binary
<application>OpenJDK</application> with the following commands as the
<systemitem class="username">root</systemitem> user:
</para>
<screen role="root"><userinput>install -vdm755 /opt/OpenJDK-&openjdk-version;-bin &amp;&amp;
mv -v * /opt/OpenJDK-&openjdk-version;-bin &amp;&amp;
chown -R root:root /opt/OpenJDK-&openjdk-version;-bin</userinput></screen>
<para>
The binary version is now installed. You may create a symlink to that
version by issuing, as the <systemitem class="username">root</systemitem>
user:
</para>
<screen role="root"><userinput>ln -sfn OpenJDK-&openjdk-version;-bin /opt/jdk</userinput></screen>
<para>
You may now proceed to <xref linkend="ojdk-conf"/>, where the
instructions assume that the above link exists.
</para>
</sect2>
</sect1>