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1	<?xml version='1.0'?>	1	<?xml version="1.0" encoding="UTF-8"?>
2	<?xml-stylesheet href="/xsl/guide.xsl" type="text/xsl"?>	2	<!DOCTYPE guide SYSTEM "/dtd/guide.dtd">
		3	<!-- $Header: /var/cvsroot/gentoo/xml/htdocs/doc/en/java.xml,v 1.52 2011/11/08 23:38:12 nightmorph Exp $ -->
		4
3	<guide>	5	<guide>
4	<title>Gentoo Java Guide</title>	6	<title>Gentoo Java Guide</title>
		7
5	<author title="Author and Editor">	8	<author title="Author">
6	<mail link="karltk@gentoo.org">Karl Trygve Kalleberg</mail>	9	<mail link="nichoj@gentoo.org">Joshua Nichols</mail>
7	</author>	10	</author>
		11	<author title="Author">
		12	<mail link="karltk@gentoo.org">Karl Trygve Kalleberg</mail>
		13	</author>
		14	<author title="Editor">
		15	<mail link="nightmorph@gentoo.org">Joshua Saddler</mail>
		16	</author>
8		17
9	<abstract>	18	<abstract>
10	Users' and Developers' Guide to Java in Gentoo	19	This guide will introduce you to Java and explain how to use Java with Gentoo
		20	Linux.
11	</abstract>	21	</abstract>
12		22
		23	<!-- The content of this document is licensed under the CC-BY-SA license -->
		24	<!-- See http://creativecommons.org/licenses/by-sa/2.5 -->
		25	<license/>
		26
13	<version>0.1.1</version>	27	<version>3</version>
14	<date>June 25, 2002</date>	28	<date>2011-11-08</date>
15		29
16	<chapter>	30	<chapter>
17		31	<title>What is Java?</title>
18	<title>Installing a JDK/JRE</title>
19	<section>	32	<section>
20	<title>Overview</title>	33	<title>Overview</title>
21	<body>	34	<body>
22	<p>Gentoo provides numerous JDKs and JREs. The default is the
23	Blackdown JDK/JRE pair, as it is freely (beer) available without any
24	registration fuss.</p>
25		35
26	<note>As kaffe becomes a JRE/JDK drop-in replacement, that will most	36	<p>
27	likely become our default.</note>	37	Java is a programming language developed by engineers of Sun Microsystems. The
		38	language is object-oriented and designed to run on multiple platforms without
		39	the need of recompiling code for each platform. Although Java can be compiled
		40	as a native program, much of Java's popularity can be attributed to its
		41	portability, along with other features such as garbage collection. To make
		42	platform independence possible the Java compiler compiles the Java code to an
		43	intermediate representation called "Java bytecode" that runs on a JRE (Java
		44	Runtime Environment) and not directly on the operating system.
		45	</p>
28		46
29	<p>Both the Sun JDK/JRE and the IBM JDK/JRE are generally faster, but	47	<p>
30	getting them is a bit more work, as you are required to read and	48	In order to run Java bytecode, one needs to have a JRE (Java Runtime
31	accept their license before downloading (IBM additionally requires you	49	Environment) installed. A JRE provides core libraries, a platform dependent
32	to register).</p>	50	Java Virtual Machine, plugins for browsers, among other things. A JDK (Java
		51	Development Kit) adds programming tools, such as a bytecode compiler and a
		52	debugger.
		53	</p>
33		54
34	<p>Our ebuilds for the Sun and IBM JDK/JREs will notify you of where
35	to go to download them.</p>
36	</body>	55	</body>
37	</section>
38
39	<section>	56	</section>
40	<title>Installing the Sun/IBM JDK/JREs</title>	57	</chapter>
		58
		59	<chapter>
		60	<title>Installing a Virtual Machine</title>
		61	<section>
		62	<title>The choices</title>
		63	<body>
		64
		65	<p>
		66	Gentoo provides numerous Runtime Environments (JREs) and Development Kits
		67	(JDKs). Among the current choices, we have:
		68	</p>
		69
		70	<table>
		71	<tr>
		72	<th>Vendor</th>
		73	<th>JDK</th>
		74	<th>JRE</th>
		75	</tr>
		76	<tr>
		77	<ti>Sun's Java Kit</ti>
		78	<ti>dev-java/sun-jdk</ti>
		79	<ti>dev-java/sun-jre-bin</ti>
		80	</tr>
		81	<tr>
		82	<ti>The IBM Java Kit</ti>
		83	<ti>dev-java/ibm-jdk-bin</ti>
		84	<ti>dev-java/ibm-jre-bin</ti>
		85	</tr>
		86	<tr>
		87	<ti>BEA WebLogic's J2SE Development Kit</ti>
		88	<ti>dev-java/jrockit-jdk-bin</ti>
		89	</tr>
		90	<tr>
		91	<ti>The IcedTea Open Java Kit</ti>
		92	<ti>dev-java/icedtea-bin</ti>
		93	</tr>
		94	</table>
		95
		96	<!--
		97	TODO: list free implementations?
		98	note about not drop-in replacements
		99	kaffe/sablevm/gcj/jamvm
		100	-->
41	<body>	101	</body>
42	<p>If you run <c>emerge dev-java/sun-jdk-1.3.1</c> or <c>emerge	102	</section>
43	dev-java/ibm-jdk-1.3.1</c>, you will be notified that you are required	103	<section>
44	to download the actual tarballs yourself. This has to do with license	104	<title>Installing a JRE/JDKs</title>
45	restrictions for the Sun JDK/JRE (online click-wrap license) and	105	<body>
46	registration issues with the IBM JDK/JRE.</p>
47		106
48	<note>There is also a dev-java/sun-jdk-1.4.0, but not all packages	107	<p>
49	work nicely with Java 1.4, so you're on your own if you use the 1.4.0	108	To install your profile's default JDK, you can run <c>emerge virtual/jdk</c>.
		109	Or to install your profile's default JRE, you can <c>emerge virtual/jre</c>.
		110	</p>
		111
		112	<p>
		113	Some JDKs and JREs, including the Sun packages, require accepting an End User
		114	License Agreement, or EULA. If its license (such as dlj-1.1) is not listed in
		115	ACCEPT_LICENSE in <path>/etc/make.conf</path>, then you won't be able to install
		116	the JDK/JRE. For more information on how to add acceptable licenses to
		117	<path>make.conf</path>, please read the <uri
		118	link="/doc/en/handbook/handbook-x86.xml?part=2&chap=1#doc_chap4">Portage
		119	Handbook</uri>.
		120	</p>
		121
		122	<p>
		123	To avoid any restrictive license hassle, consider installing
		124	<c>icedtea-bin</c>, which is an open Java implementation from the OpenJDK
		125	project.
		126	</p>
		127
		128	<note>
		129	A JDK also includes a JRE, so if you install a JDK you shouldn't have to also
		130	have to install a JRE.
50	JDK.</note>	131	</note>
51		132
		133	</body>
		134	</section>
		135	<section>
		136	<title>Installing fetch-restricted virtual machines</title>
		137	<body>
		138
		139	<p>
		140	Some of the JDKs and JREs require you to jump through a few hoops before
		141	installing. Simply emerge the packages as you normally would. The ebuilds will
		142	then instruct you where to go and what to download.
		143	</p>
		144
		145	<p>
52	<p>You should download the indicated file(s) into	146	You should download the indicated file(s) into
53	<path>/usr/portage/distfiles</path>. Once that is done, you can rerun	147	<path>/usr/portage/distfiles</path>. Once there, you can rerun the emerge
54	the emerge command, then the JDK/JRE will be installed properly into	148	command, at which point the JRE/JDK will be begin to install.
55	<path>/opt</path>.</p>	149	</p>
56	</body>
57	</section>
58	</chapter>
59		150
		151	</body>
		152	</section>
60	<chapter>	153	</chapter>
61	<title>Configuring your JDK/JRE</title>	154
		155	<chapter>
		156	<title>Configuring your virtual machine</title>
62	<section>	157	<section>
63	<title>Overview</title>	158	<title>Overview</title>
64	<body>	159	<body>
		160
		161	<p>
65	<p>Gentoo has the ability to have multiple JDKs and JREs installed	162	Gentoo has the ability to have multiple JDKs and JREs installed without causing
66	without them conflicting. There are a few caveats to this, as noted	163	conflicts.
67	below.</p>	164	</p>
68		165
		166	<p>
69	<p>Using the <c>java-config</c> tool, you can set the system-wide	167	Using the <c>java-config</c> tool, you can set the system-wide default
70	default if you have root access. Users can also use <c>java-config</c>	168	(provided you have root access). Users can also use <c>java-config</c> to set
71	to set up their own personal default, that is different from the	169	up their own personal default.
72	system-wide default.</p>	170	</p>
73	</body>
74	</section>
75		171
		172	<note>
		173	You can also use <e>eselect</e> to change the system and user vm. See
		174	<c>eselect java-vm help</c>.
		175	</note>
		176
		177	</body>
76	<section>	178	</section>
		179	<section>
77	<title>Setting a default JDK/JRE</title>	180	<title>Setting a default virtual machine</title>
78	<body>	181	<body>
		182
		183	<p>
79	<p>Running the command <c>java-config --list-available-vms</c> will	184	Running the command <c>java-config --list-available-vms</c> will give you a
80	give you a list of all availble JREs and JDKs on your system, thus:</p>	185	list of all JREs and JDKs installed on your system. Here is an example of
		186	output:
		187	</p>
		188
		189	<pre caption="Listing available VMs">
		190	# <i>java-config --list-available-vms</i>
		191	The following VMs are available for generation-2:
		192	1) IcedTea-bin 1.10.4 [icedtea-bin]
		193	2) Sun JDK 1.5.0.20 [sun-jdk-1.5] <comment>(Build Only)</comment>
		194	*) Sun JDK 1.6.0.16 [sun-jdk-1.6]
81	<pre>	195	</pre>
82	[%1 ~] java-config --list-available-vms	196
83	[blackdown-jdk-1.3.1] Blackdown JDK 1.3.1 (/etc/env.d/java/20blackdown-jdk-1.3.1)	197	<note>
84	[blackdown-jre-1.3.1] Blackdown JRE 1.3.1 (/etc/env.d/java/20blackdown-jre-1.3.1)	198	VMs marked as Build Only may contain security vulnerabilities and/or be EOL.
85	[ibm-jdk-1.3.0] IBM JDK 1.3.0 (/etc/env.d/java/20ibm-jdk-1.3.0)	199	Gentoo recommends not setting these VMs as either your system or user VM.
86	[ibm-jdk-1.3.1] IBM JDK 1.3.1 (/etc/env.d/java/20ibm-jdk-1.3.1)	200	Please see <uri link="java.xml#build-only">Build Only VM</uri> for more
87	[ibm-jre-1.3.1] IBM JRE 1.3.1 (/etc/env.d/java/20ibm-jre-1.3.1)	201	information.
88	[sun-jdk-1.4.0] Sun JDK 1.4.0 (/etc/env.d/java/20sun-jdk-1.4.0)	202	</note>
89	</pre>	203
		204	<p>
		205	The <e>*</e> indicates this is the current active vm (system-vm or user-vm when
90	<p>The name in the brackets <path>"[]"</path> is the handle or ID for	206	set). The name in the brackets (<e>[]</e>) is the handle or ID for that
91	that particular VM. You use pass that ID to <c>java-config	207	particular VM. You use the handle or the number to <c>java-config
92	--set-system-vm</c>, thus:</p>	208	--set-system-vm</c>. Here is an example of how to set the system VM.
		209	</p>
		210
		211	<pre caption="Setting the System VM">
		212	<comment>(By handle (preferred))</comment>
		213	# <i>java-config --set-system-vm sun-jdk-1.6</i>
		214	Now using sun-jdk-1.6 as your generation-2 system JVM
		215	<comment>(By number)</comment>
		216	# <i>java-config --set-system-vm 3</i>
		217	Now using sun-jdk-1.6 as your generation-2 system JVM
93	<pre>	218	</pre>
94	[#1 ~] java-config --set-system-vm=ibm-jdk-1.3.1
95	Now using IBM JDK 1.3.1 (/etc/env.d/java/20ibm-jdk-1.3.1)
96	</pre>
97		219
98	<note>You will have to be root to run --set-system-vm</note>
99
100	<p>Once you have issued <c>java-config --set-system-vm</c> with a
101	particular VM ID, you will need to regenerate your /etc/profile.env,
102	thus:</p>
103	<pre>	220	<p>
104	[#1 ~] env-update
105	</pre>
106
107	<p>After this, you will either want to relogin, or resource
108	<path>/etc/profile</path> into your environment.</p>
109
110	<p>As a regular user, you can use <c>java-config --set-user-vm</c>,	221	As a regular user, you can use <c>java-config --set-user-vm</c>.
111	which will create <path>$HOME/.gentoo/java-env</path> with all	222	</p>
112	required env vars. You would normally source this from your shell's
113	startup script (<path>$HOME/.zshenv</path> in my case).</p>
114	</body>
115	</section>
116		223
		224	<note>
		225	You no longer have to <c>source</c> the profile for updates to the user/system
		226	VM take place.
		227	</note>
		228
		229	</body>
117	<section>	230	</section>
		231	<section id="build-only">
		232	<title>Build Only VM</title>
		233	<body>
		234
		235	<p>
		236	Some virtual machines are flagged as build-only due to being EOL and/or
		237	containing security vulnerabilities. These virtual machines will not
		238	automatically be used by Gentoo for the running of applications using Gentoo
		239	launchers but will still be available for use by Gentoo's build environment as
		240	some packages may require them for building. The setting of these virtual
		241	machines as either your system or user VM is strongly discouraged as these VMs
		242	will then be used when running the <path>/usr/bin/{java,javac,..}</path>
		243	executables and will also be used by any packages not using Gentoo's launcher
		244	scripts.
		245	</p>
		246
		247	</body>
		248	</section>
		249	<section id="preferred-vm">
		250	<title>Preferred Build VM</title>
		251	<body>
		252
		253	<p>
		254	While merging Java packages, the VM used for building can sometimes be different
		255	from the one currently set as the system VM.
		256	</p>
		257
		258	<p>
		259	This merge time VM switching is needed when, for example, your system-vm is
		260	set to a 1.6 VM and the package you are merging requires a 1.5 VM. While merging
		261	it will select and use a 1.5 VM, leaving your system-vm choice intact.
		262	</p>
		263
		264	<p>
		265	To define which VM is selected when a switch is needed, we have created a list of <e>default/supported
		266	VMs</e> per arch. You can find them in
		267	<path>/usr/share/java-config-2/config/jdk-defaults.conf</path>.
		268	</p>
		269
		270	<p>
		271	You can override these defaults (and even your selected system VM) in
		272	<path>/etc/java-config-2/build/jdk.conf</path> and have complete control over
		273	which VM will get used for merging. Some examples:
		274	</p>
		275
		276	<pre caption="Example /etc/java-config-2/build/jdk.conf">
		277	<comment>(I always want it to use a sun-jdk, ie sun-jdk-1.4 for 1.4, sun-jdk-1.5 for 1.5, etc)</comment>
		278	*=sun-jdk
		279	</pre>
		280
		281	<pre caption="Example /etc/java-config-2/build/jdk.conf">
		282	<comment>(Always use sun-jdk-1.5 wherever possible, except for when a 1.4 or 1.3 VM is explicitly required)</comment>
		283	*=sun-jdk-1.5
		284	</pre>
		285
		286	<pre caption="Example /etc/java-config-2/build/jdk.conf">
		287	<comment># For 1.3 I prefer sun-jdk 1.4 but when it is not available, use ibm-jdk-bin,
		288	# For 1.5, use sun-jdk </comment>
		289	1.3=sun-jdk-1.4 ibm-jdk-bin
		290	1.5=sun-jdk
		291	</pre>
		292
		293	<warn>
		294	You do not <e>have</e> to edit this file. If you change these options to use a
		295	unsupported VM, things could possibly break. Because of the wide variety of
		296	available VMs, we do not have the resources to test and verify every package
		297	works on all of them. Bugs reported with a unsupported VM won't be prioritized
		298	as much as bugs present within supported VMs.
		299	</warn>
		300
		301	</body>
		302	</section>
		303	</chapter>
		304
		305	<chapter>
		306	<title>Compilers</title>
		307	<section>
		308	<body>
		309
		310	<p>
		311	The standard Java compiler used for building is <c>javac</c>, which comes with
		312	each JDK. In addition to configuring the VM used at build time, it is also
		313	possible configure which compiler is used. Essentially, you define a list your
		314	preference for which compiler to use in
		315	<path>/etc/java-config-2/build/compilers.conf</path>.
		316	</p>
		317
		318	<pre caption="/etc/java-config-2/build/compilers.conf">
		319	# If the ebuild supports it
		320	# it will check the COMPILERS var front to back and
		321	# use the first compiler that is installed
		322
		323	COMPILERS="ecj-X.Y jikes javac"
		324	</pre>
		325
		326	<p>
		327	Some compilers don't support all possible -target and -source arguments.
		328	Therefore, each compiler in the list is checked to see if it can support the
		329	desired -source/-target. javac will work in all cases, so if no other suitable
		330	compiler is found, it will be used instead.
		331	</p>
		332
		333	<p>
		334	More details about each compiler are provided below:
		335	</p>
		336
		337	<table>
		338	<tr>
		339	<th>Name</th>
		340	<th>Handle</th>
		341	<th>Package</th>
		342	<th>Description</th>
		343	</tr>
		344	<tr>
		345	<ti>javac</ti>
		346	<ti>javac</ti>
		347	<ti>N/A</ti>
		348	<ti>
		349	This is the default compiler that will be used, and comes with each JDK.
		350	</ti>
		351	</tr>
		352	<tr>
		353	<ti>jikes</ti>
		354	<ti>jikes</ti>
		355	<ti>dev-java/jikes</ti>
		356	<ti>
		357	Jikes was originally developed by IBM. Anecdotally, it is generally quicker
		358	than javac. Note however, that it is more pedantic, and will fail under a
		359	few circumstances where javac has no issue. It also does not support Java
		360	1.5 syntax yet.
		361	</ti>
		362	</tr>
		363	<tr>
		364	<ti>Eclipse Compiler for Java</ti>
		365	<ti>ecj</ti>
		366	<ti>dev-java/eclipse-ecj</ti>
		367	<ti>
		368	ECJ is the compiler used by the Eclipse software development kit. It is
		369	very full featured, and is pretty fast. It does support Java 1.5 syntax.
		370	</ti>
		371	</tr>
		372	</table>
		373
		374	</body>
		375	</section>
		376	</chapter>
		377
		378	<chapter>
118	<title>Setting a default CLASSPATH</title>	379	<title>Setting a default CLASSPATH</title>
		380	<section>
119	<body>	381	<body>
		382
		383	<warn>
		384	The options explained in this section should be considered deprecated and will
		385	most likely be removed in the future. We strongly recommend against using
		386	these, because your Java projects or application should ideally manage their
		387	own classpaths. If you choose to specify a default CLASSPATH, some applications
		388	may behave unexpectedly, because classes they weren't expecting would be on the
		389	classpath.
		390	</warn>
		391
		392	<p>
120	<p><c>java-config</c> can also be used to set a system-wide default	393	<c>java-config</c> can also be used to set a system-wide default CLASSPATH, as
121	CLASSPATH, and of course a user-specific default CLASSPATH.</p>	394	well a user-specific default CLASSPATH.
		395	</p>
122		396
123	<p>First you want to list available java libraries that might be	397	<p>
124	interesting to put in your CLASSPATH, thus:</p>	398	First, you will want to list available Java libraries installed on your system
		399	that might want to be put in your CLASSPATH. Here is an example of output:
		400	</p>
		401
		402	<pre caption="Listing classes">
		403	# <i>java-config --list-available-packages</i>
		404	[xerces-2] The next generation of high performance, fully compliant XML parsers in the Apache Xerces family (/usr/share/xerces-2/package.env)
		405	[junit] Simple framework to write repeatable tests (/usr/share/junit/package.env)
		406	[bsh] BeanShell: A small embeddable Java source interpreter (/usr/share/bsh/package.env)
		407	[bcel] The Byte Code Engineering Library: analyze, create, manipulate Java class files (/usr/share/bcel/package.env)
		408	[log4j] A low-overhead robust logging package for Java (/usr/share/log4j/package.env)
		409	...
125	<pre>	410	</pre>
126	[%1 ~] java-config --list-available-packages	411
127	[ant] No description (/usr/share/ant/classpath.env)	412	<p>
128	[java-gnome] No description (/usr/share/java-gnome/classpath.env)	413	Again, the names in brackets (<e>[]</e>) are the IDs that you have to pass to
129	[java-gtk] No description (/usr/share/java-gtk/classpath.env)	414	<c>java-config --set-system-classpath</c>. Here is an example:
130	[log4j] "" (/usr/share/log4j/package.env)
131	</pre>	415	</p>
132		416
133	<note>None of these packages have a proper description. That is	417	<pre caption="Setting classpaths">
134	something that will be implemented in the not-so-distant	418	# <i>java-config --set-system-classpath log4j,xerces-2</i>
135	future.</note>
136
137	<p>Again, the name in brackets <path>"[]"</path> are the IDs that you
138	have to pass to <c>java-config --set-system-classpath</c>, thus:</p>
139	<pre>	419	</pre>
140	java-config --set-system-classpath=log4j,java-gtk,java-gnome	420
		421	<note>
		422	The current directory (<path>.</path>) will not be part of the system
		423	classpath, as that should be added in your system's login profile.
		424	</note>
		425
		426	<p>
		427	You will have to update your environment by logging out, then in again or
		428	sourcing <path>/etc/profile</path>.
141	</pre>	429	</p>
142	<note>The current directory (.) will not be part of the system classpath,	430
143	as that should be added in root's login profile.</note>	431	<p>
144	<p>Again, you will want to run <c>env-update</c> to update your
145	system's environment, and you might also want to relogin or resource
146	the <path>/etc/profile</path>.</p>
147	<p>For users, <c>java-config --set-user-classpath</c> will create	432	For users, <c>java-config --set-user-classpath</c> will create
148	<path>$HOME/.gentoo/java-env-classpath</path>, which is automatically	433	<path>~/.gentoo/java-env-classpath</path>, which you should then source from
149	included by <path>$HOME/.gentoo/java-env</path>.</p>	434	your shell's profile.
		435	</p>
		436
		437	<pre caption="Sourcing user specific classpath">
		438	<i>if [[ -f "${HOME}/.gentoo/java-env-classpath" ]]; then
		439	source ${HOME}/.gentoo/java-env-classpath
		440	fi</i>
		441	</pre>
		442
		443	<p>
		444	If you really want a system wide or user default classpath you can add
		445	something like the following to your shell's profile. But we would advise
		446	against it.
		447	</p>
		448
		449	<pre caption="Setting classpath">
		450	# <i>export CLASSPATH="${CLASSPATH}:$(java-config --classpath log4j,xerces-2)"</i>
		451	</pre>
		452
		453	</body>
		454	</section>
		455	</chapter>
		456
		457	<chapter>
		458	<title>Java Browser Plugins</title>
		459	<section>
		460	<title>Installing a plugin</title>
		461	<body>
		462
		463	<p>
		464	You can install a Java plugin for your web browser by emerging a Java VM with
		465	the <c>nsplugin</c> USE flag set.
		466	</p>
		467
		468	<note>
		469	<c>nsplugin</c> is not available for all architectures. Check for available
		470	plugins on your arch before trying to install a VM by running <c>emerge -pv
		471	<java-vm></c>.
		472	</note>
		473
		474	<p>
		475	Portage will allow you to install multiple versions of Java plugins, though
		476	only one will be used by your browser. You can check the list of available
		477	plugins by running:
		478	</p>
		479
		480	<pre caption="Viewing available plugins">
		481	# <i>eselect java-nsplugin list</i>
		482	[1] sun-jre-bin-1.6
		483	[2] icedtea-bin
		484	</pre>
		485
		486	<p>
		487	In this example, <c>sun-jre-bin</c> is selected for the browser plugin.
		488	</p>
		489
		490	<pre caption="Selecting a plugin">
		491	# <i>eselect java-nsplugin set sun-jre-bin-1.6</i>
		492	</pre>
		493
		494	<p>
		495	Verify that the correct plugin was selected:
		496	</p>
		497
		498	<pre caption="Verifying the correct plugin">
		499	# <i>eselect java-nsplugin list</i>
		500	[1] sun-jre-bin-1.6 current
		501	[2] icedtea-bin
		502	</pre>
		503
		504	<p>
		505	Java.com also provides a link to <uri
		506	link="http://java.com/en/download/installed.jsp">verify your installed
		507	plugin</uri>. Additionally, if you are using a Mozilla-based browser, you can
		508	verify your Java plugin by typing <c>about:plugins</c> into the address bar.
		509	</p>
		510
		511	</body>
		512	</section>
		513	<section>
		514	<title>Plugins on multilib systems</title>
		515	<body>
		516
		517	<p>
		518	If you are running a mixed 64-bit and 32-bit multilib system (for example, on
		519	AMD64), you can use 64-bit and 32-bit Java plugins. Unless you have a pressing
		520	need to run 32-bit Java applications, we recommend using native 64-bit plugins
		521	on 64-bit web browsers.
		522	</p>
		523
		524	<p>
		525	There are several native 64-bit browser plugins available. The default JDK/JRE
		526	pair, <c>sun-jdk</c> and <c>sun-jre-bin</c>, both include browser plugins. Just
		527	emerge one of them with the <c>nsplugin</c> USE flag enabled.
		528	</p>
		529
		530	<pre caption="Installing a 64-bit plugin">
		531	# <i>echo "dev-java/sun-jre-bin nsplugin" >> /etc/portage/package.use</i>
		532	# <i>emerge sun-jre-bin</i>
		533	</pre>
		534
		535	<p>
		536	To use a 32-bit plugin on a 32-bit browser, you will need to emerge
		537	<c>emul-linux-x86-java</c> with the <c>nsplugin</c> USE flag enabled.
		538	</p>
		539
		540	<pre caption="Installing a 32-bit plugin">
		541	# <i>echo "app-emulation/emul-linux-x86-java nsplugin" >> /etc/portage/package.use</i>
		542	# <i>emerge emul-linux-x86-java</i>
		543	</pre>
		544
		545	<p>
		546	Next, check which plugins are available:
		547	</p>
		548
		549	<pre caption="Viewing available plugins">
		550	# <i>eselect java-nsplugin list</i>
		551	Available 32-bit Java browser plugins
		552	[1] emul-linux-x86-java-1.5
		553	[2] emul-linux-x86-java-1.6
		554	Available 64-bit Java browser plugins
		555	[1] icedtea-bin
		556	[2] sun-jre-bin-1.6
		557	</pre>
		558
		559	<p>
		560	Now select the right plugin for your browsers:
		561	</p>
		562
		563	<pre caption="Selecting plugins">
		564	<comment>(Choose the plugins for 32-bit and 64-bit browsers)</comment>
		565	# <i>eselect java-nsplugin set 32bit emul-linux-x86-java-1.6</i>
		566	# <i>eselect java-nsplugin set 64bit sun-jre-bin-1.6</i>
		567	</pre>
		568
		569	<p>
		570	Verify the correct plugin was selected:
		571	</p>
		572
		573	<pre caption="Verifying the correct plugin">
		574	# <i>eselect java-nsplugin list</i>
		575	Available 32-bit Java browser plugins
		576	[1] emul-linux-x86-java-1.5
		577	[2] emul-linux-x86-java-1.6 current
		578	Available 64-bit Java browser plugins
		579	[1] icedtea-bin
		580	[2] sun-jre-bin-1.6 current
		581	</pre>
		582
		583	</body>
		584	</section>
		585	</chapter>
		586
		587	<chapter>
		588	<title>USE flags for use with Java</title>
		589	<section>
		590	<title>Setting USE flags</title>
		591	<body>
		592
		593	<p>
		594	For more information regarding USE flags, refer to the <uri
		595	link="/doc/en/handbook/handbook-x86.xml?part=2&chap=2">USE flags</uri>
		596	chapter from the Gentoo Handbook.
		597	</p>
		598
		599	</body>
		600	</section>
		601	<section>
		602	<title>The flags</title>
		603	<body>
		604
		605	<ul>
		606	<li>The <b>java</b> flag adds support for Java in a variety of programs</li>
		607	<li>
		608	The <b>nsplugin</b> flag adds support for Mozilla-like browsers (including
		609	Firefox). You will need this for viewing Java applets in your Mozilla-like
		610	browser.
		611	</li>
		612	<li>
		613	The <b>source</b> flag installs a zip of the source code of a package.
		614	This is traditionally used for IDEs to 'attach' source to the libraries you
		615	are using.
		616	</li>
		617	<li>The <b>jce</b> flag adds support for the Java Cryptography Engine</li>
		618	<li>
		619	For Java packages, the <b>doc</b> flag will build API documentation using
		620	javadoc.
		621	</li>
		622	</ul>
		623
150	</body>	624	</body>
151	</section>	625	</section>
152	</chapter>	626	</chapter>
153		627
154	<chapter>	628	<chapter>
155	<title>Additional resources</title>	629	<title>Additional resources</title>
156	<section>	630	<section>
157	<title>Off-line resources</title>	631	<title>Off-line resources</title>
158	<body>	632	<body>
		633
159	<ul>	634	<ul>
160	<li>java-config man page</li>	635	<li>java-config man page</li>
161	<li><c>java-config --help</c></li>	636	<li><c>java-config --help</c></li>
162	<li>The <path>/usr/bin/java-config</path> script itself</li>
163	</ul>	637	</ul>
		638
164	</body>	639	</body>
165	</section>	640	</section>
166	<section>	641	<section>
167	<title>Online resources</title>	642	<title>Online resources</title>
168	<body>	643	<body>
		644
169	<ul>	645	<ul>
170	<li>The <uri link="http://lists.gentoo.org/pipermail/gentoo-dev/">	646	<li>
171	gentoo-dev </uri>,	647	The <uri link="http://www.gentoo.org/proj/en/java/">Java Project
172	<uri link="http://lists.gentoo.org/pipermail/gentoo-user/"> gentoo-user	648	Page</uri>
		649	</li>
		650	<li>
		651	The <uri
		652	link="http://news.gmane.org/gmane.linux.gentoo.java">gentoo-java</uri>,
		653	<uri
		654	link="http://news.gmane.org/gmane.linux.gentoo.user">gentoo-user</uri>, and
		655	<uri
		656	link="http://news.gmane.org/gmane.linux.gentoo.devel">gentoo-dev</uri>
173	</uri> mailing list archives</li>	657	mailing list archives
174	<li>#gentoo on irc.openprojects.net</li>	658	</li>
		659	<li>
		660	<uri link="irc://irc.gentoo.org/gentoo">#gentoo</uri> and <uri
		661	link="irc://irc.gentoo.org/gentoo-java">#gentoo-java</uri> on IRC
		662	</li>
		663	<li>
		664	<uri
		665	link="http://en.wikipedia.org/wiki/Java_programming_language">Wikipedia's
		666	entry for Java</uri>
		667	</li>
		668	<li>
		669	If you have suggestions or questions regarding this document, please email
		670	the Gentoo Java team: <mail>java@gentoo.org</mail>
		671	</li>
175	</ul>	672	</ul>
176	</body>
177	</section>
178	</chapter>
179	<chapter>
180	<title>Caveats</title>
181	<section>
182	<title>General</title>
183	<body>
184	<p>If you select a JRE as your default VM, you may not have a
185	<c>javac</c> command handy at all times, unless you have manually
186	installed a symlink to take care of that.</p>
187		673
188	<p>Jikes will be used to compile some of the largest packages, if it
189	is available. With time, we hope to be able to compile all
190	java-dependent packages with Jikes, so some dependencies on the JDK
191	can be replaced with a dependency on the JRE.</p>
192
193	<p>With some versions of Portage, doing an <c>emerge --world
194	update</c> will install the JDK regardless if whether you have it
195	installed before or not. This is a known bug addressed in later
196	versions of Portage.</p>
197	</body>	674	</body>
198	</section>	675	</section>
199	</chapter>	676	</chapter>
200	</guide>	677	</guide>

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