/[gentoo]/xml/htdocs/doc/en/java.xml

Diff of /xml/htdocs/doc/en/java.xml

Parent Directory | Revision Log | View Patch Patch

Revision 1.4		Revision 1.44
1	<?xml version='1.0' encoding="UTF-8"?>	1	<?xml version="1.0" encoding="UTF-8"?>
2	<?xml-stylesheet href="/xsl/guide.xsl" type="text/xsl"?>	2	<!-- $Header: /var/cvsroot/gentoo/xml/htdocs/doc/en/java.xml,v 1.44 2009/10/07 18:14:31 nightmorph Exp $ -->
		3	<!DOCTYPE guide SYSTEM "/dtd/guide.dtd">
3		4
4	<guide link = "/doc/en/java.xml">	5	<guide link="/doc/en/java.xml">
5	<title>Gentoo Java Guide</title>	6	<title>Gentoo Java Guide</title>
		7
6	<author title="Author and Editor">	8	<author title="Author">
		9	<mail link="nichoj@gentoo.org">Joshua Nichols</mail>
		10	</author>
		11	<author title="Author">
7	<mail link="karltk@gentoo.org">Karl Trygve Kalleberg</mail>	12	<mail link="karltk@gentoo.org">Karl Trygve Kalleberg</mail>
8	</author>	13	</author>
		14	<author title="Editor">
		15	<mail link="nightmorph@gentoo.org">Joshua Saddler</mail>
		16	</author>
9		17
10	<abstract>	18	<abstract>
11	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.
12	</abstract>	21	</abstract>
13		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
14	<version>0.1.1</version>	27	<version>0.19</version>
15	<date>June 25, 2002</date>	28	<date>2009-10-07</date>
16		29
17	<chapter>	30	<chapter>
18	<title>Installing a JDK/JRE</title>	31	<title>What is Java?</title>
19	<section>	32	<section>
20	<title>Overview</title>	33	<title>Overview</title>
21	<body>	34	<body>
22
23	<p>Gentoo provides numerous JDKs and JREs. The default is the
24	Blackdown JDK/JRE pair, as it is freely (beer) available without any
25	registration fuss.
26	</p>
27		35
28	<note>As kaffe becomes a JRE/JDK drop-in replacement, that will most	36	<p>
29	likely become our default.	37	Java is a programming language developed by engineers of Sun Microsystems. The
30	</note>	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>
31		46
32	<p>Both the Sun JDK/JRE and the IBM JDK/JRE are generally faster, but	47	<p>
33	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
34	accept their license before downloading (IBM additionally requires you	49	Environment) installed. A JRE provides core libraries, a platform dependent
35	to register).	50	Java Virtual Machine, plugins for browsers, among other things. A JDK (Java
36	</p>	51	Development Kit) adds programming tools, such as a bytecode compiler and a
		52	debugger.
		53	</p>
37		54
38	<p>Our ebuilds for the Sun and IBM JDK/JREs will notify you of where
39	to go to download them.
40	</p>
41
42	</body>	55	</body>
43	</section>	56	</section>
44
45	<section>
46	<title>Installing the Sun/IBM JDK/JREs</title>
47	<body>
48
49	<p>If you run <c>emerge sun-jdk-1.3.1</c> or <c>emerge
50	ibm-jdk-1.3.1</c>, you will be notified that you are required
51	to download the actual tarballs yourself. This has to do with license
52	restrictions for the Sun JDK/JRE (online click-wrap license) and
53	registration issues with the IBM JDK/JRE.
54	</p>
55
56	<note>There is also a sun-jdk-1.4.0, but not all packages
57	work nicely with Java 1.4, so you're on your own if you use the 1.4.0
58	JDK.
59	</note>
60
61	<p>You should download the indicated file(s) into
62	<path>/usr/portage/distfiles</path>. Once that is done, you can rerun
63	the emerge command, then the JDK/JRE will be installed properly into
64	<path>/opt</path>.
65	</p>
66
67	</body>
68	</section>
69	</chapter>	57	</chapter>
70		58
71	<chapter>	59	<chapter>
72	<title>Configuring your JDK/JRE</title>	60	<title>Before You Begin</title>
73
74	<section>	61	<section>
		62	<title>Existing installs</title>
		63	<body>
		64
		65	<p>
		66	For existing installs, regardless of if you have installed anything Java
		67	before, make sure you have followed the <uri
		68	link="/proj/en/java/java-upgrade.xml">Java Upgrade Guide</uri>.
		69	</p>
		70
		71	</body>
		72	</section>
		73	<section>
		74	<title>New installs</title>
		75	<body>
		76
		77	<p>
		78	New installs should require no further preparation.
		79	</p>
		80
		81	</body>
		82	</section>
		83	</chapter>
		84
		85	<chapter>
		86	<title>Installing a Virtual Machine</title>
		87	<section>
		88	<title>The choices</title>
		89	<body>
		90
		91	<p>
		92	Gentoo provides numerous Runtime Environments (JREs) and Development Kits
		93	(JDKs). Among the current choices, we have:
		94	</p>
		95
		96	<table>
		97	<tr>
		98	<th>Vendor</th>
		99	<th>JDK</th>
		100	<th>JRE</th>
		101	</tr>
		102	<tr>
		103	<ti>The Blackdown Java Kit</ti>
		104	<ti>dev-java/blackdown-jdk</ti>
		105	<ti>dev-java/blackdown-jre</ti>
		106	</tr>
		107	<tr>
		108	<ti>Sun's Java Kit</ti>
		109	<ti>dev-java/sun-jdk</ti>
		110	<ti>dev-java/sun-jre-bin</ti>
		111	</tr>
		112	<tr>
		113	<ti>The IBM Java Kit</ti>
		114	<ti>dev-java/ibm-jdk-bin</ti>
		115	<ti>dev-java/ibm-jre-bin</ti>
		116	</tr>
		117	<tr>
		118	<ti>BEA WebLogic's J2SE Development Kit</ti>
		119	<ti>dev-java/jrockit-jdk-bin</ti>
		120	</tr>
		121	</table>
		122
		123	<!--
		124	TODO: list free implementations?
		125	note about not drop-in replacements
		126	kaffe/sablevm/gcj/jamvm
		127	-->
		128	<p>
		129	The default for Java 1.6 is the Sun JRE/JDK pair.
		130	</p>
		131
		132	</body>
		133	</section>
		134	<section>
		135	<title>Installing a JRE/JDKs</title>
		136	<body>
		137
		138	<p>
		139	To install your profile's default JDK, you can run <c>emerge virtual/jdk</c>.
		140	Or to install your profile's default JRE, you can <c>emerge virtual/jre</c>.
		141	</p>
		142
		143	<p>
		144	In recent events, Sun has relicensed their JDK and JRE under a more Linux
		145	distro friendly license. As a result, Sun releases Java 1.5 and onwards are
		146	freely downloadable, without any further hassle.
		147	</p>
		148
		149	<note>
		150	A JDK also includes a JRE, so if you install a JDK you shouldn't have to also
		151	have to install a JRE.
		152	</note>
		153
		154	</body>
		155	</section>
		156	<section>
		157	<title>Installing fetch-restricted virtual machines</title>
		158	<body>
		159
		160	<p>
		161	Some of the JDKs and JREs require you to jump through a few hoops before
		162	installing. Simply emerge the packages as you normally would. The ebuilds will
		163	then instruct you where to go and what to download.
		164	</p>
		165
		166	<p>
		167	You should download the indicated file(s) into
		168	<path>/usr/portage/distfiles</path>. Once there, you can rerun the emerge
		169	command, at which point the JRE/JDK will be begin to install.
		170	</p>
		171
		172	</body>
		173	</section>
		174	</chapter>
		175
		176	<chapter>
		177	<title>Configuring your virtual machine</title>
		178	<section>
75	<title>Overview</title>	179	<title>Overview</title>
76
77	<body>	180	<body>
78		181
		182	<p>
79	<p>Gentoo has the ability to have multiple JDKs and JREs installed	183	Gentoo has the ability to have multiple JDKs and JREs installed without causing
80	without them conflicting. There are a few caveats to this, as noted	184	conflicts.
81	below.	185	</p>
82	</p>
83		186
		187	<p>
84	<p>Using the <c>java-config</c> tool, you can set the system-wide	188	Using the <c>java-config</c> tool, you can set the system-wide default
85	default if you have root access. Users can also use <c>java-config</c>	189	(provided you have root access). Users can also use <c>java-config</c> to set
86	to set up their own personal default, that is different from the	190	up their own personal default.
87	system-wide default.	191	</p>
88	</p>	192
89		193	<note>
		194	You can also use <e>eselect</e> to change the system and user vm. See
		195	<c>eselect java-vm help</c>.
		196	</note>
		197
90	</body>	198	</body>
91	</section>	199	</section>
92
93	<section>	200	<section>
94	<title>Setting a default JDK/JRE</title>	201	<title>Setting a default virtual machine</title>
95	<body>	202	<body>
96		203
		204	<p>
97	<p>Running the command <c>java-config --list-available-vms</c> will	205	Running the command <c>java-config --list-available-vms</c> will give you a
98	give you a list of all availble JREs and JDKs on your system, thus:</p>	206	list of all JREs and JDKs installed on your system. Here is an example of
99		207	output:
		208	</p>
		209
100	<pre caption = "Listing available VMs">	210	<pre caption="Listing available VMs">
101	[%1 ~] java-config --list-available-vms	211	# <i>java-config --list-available-vms</i>
102	[blackdown-jdk-1.3.1] Blackdown JDK 1.3.1 (/etc/env.d/java/20blackdown-jdk-1.3.1)	212	The following VMs are available for generation-2:
103	[blackdown-jre-1.3.1] Blackdown JRE 1.3.1 (/etc/env.d/java/20blackdown-jre-1.3.1)	213	1) Blackdown JDK 1.4.2.03 [blackdown-jdk-1.4.2] <comment>(Build Only)</comment>
104	[ibm-jdk-1.3.0] IBM JDK 1.3.0 (/etc/env.d/java/20ibm-jdk-1.3.0)	214	2) Blackdown JRE 1.4.2.03 [blackdown-jre-1.4.2] <comment>(Build Only)</comment>
105	[ibm-jdk-1.3.1] IBM JDK 1.3.1 (/etc/env.d/java/20ibm-jdk-1.3.1)	215	3) IcedTea6-bin 1.4.1 [icedtea6-bin]
106	[ibm-jre-1.3.1] IBM JRE 1.3.1 (/etc/env.d/java/20ibm-jre-1.3.1)	216	4) Sun JDK 1.5.0.20 [sun-jdk-1.5] <comment>(Build Only)</comment>
107	[sun-jdk-1.4.0] Sun JDK 1.4.0 (/etc/env.d/java/20sun-jdk-1.4.0)	217	*) Sun JDK 1.6.0.16 [sun-jdk-1.6]
108	</pre>	218	</pre>
109		219
		220	<note>
		221	VMs marked as Build Only may contain security vulnerabilities and/or be EOL.
		222	Gentoo recommends not setting these VMs as either your system or user VM.
		223	Please see <uri link="java.xml#build-only">Build Only VM</uri> for more
		224	information.
		225	</note>
		226
		227	<p>
		228	The <e>*</e> indicates this is the current active vm (system-vm or user-vm when
110	<p>The name in the brackets <path>"[]"</path> is the handle or ID for	229	set). The name in the brackets (<e>[]</e>) is the handle or ID for that
111	that particular VM. You use pass that ID to <c>java-config	230	particular VM. You use the handle or the number to <c>java-config
112	--set-system-vm</c>, thus:	231	--set-system-vm</c>. Here is an example of how to set the system VM.
113	</p>	232	</p>
114		233
115	<pre caption = "Setting the System VM">	234	<pre caption="Setting the System VM">
116	[#1 ~] java-config --set-system-vm=ibm-jdk-1.3.1	235	<comment>(By handle (preferred))</comment>
117	Now using IBM JDK 1.3.1 (/etc/env.d/java/20ibm-jdk-1.3.1)	236	# <i>java-config --set-system-vm blackdown-jdk-1.4</i>
		237	Now using blackdown-jdk-1.4 as your generation-2 system JVM
		238	WARNING: blackdown-jdk-1.4 is marked as a build-only JVM. Using this vm is not recommended.
		239	<comment>(By number)</comment>
		240	# <i>java-config --set-system-vm 5</i>
		241	Now using sun-jdk-1.6 as your generation-2 system JVM
118	</pre>	242	</pre>
119		243
120	<note>You will have to be root to run --set-system-vm	244	<p>
121	</note>
122
123	<p>Once you have issued <c>java-config --set-system-vm</c> with a
124	particular VM ID, you will need to regenerate your /etc/profile.env,
125	thus:
126	</p>
127
128	<pre caption = "Regenerating /etc/profile.env" >
129	[#1 ~] env-update
130	</pre>
131
132	<p>After this, you will either want to relogin, or resource
133	<path>/etc/profile</path> into your environment.
134	</p>
135
136	<p>As a regular user, you can use <c>java-config --set-user-vm</c>,	245	As a regular user, you can use <c>java-config --set-user-vm</c>.
137	which will create <path>$HOME/.gentoo/java-env</path> with all	246	</p>
138	required env vars. You would normally source this from your shell's	247
139	startup script (<path>$HOME/.zshenv</path> in my case).</p>	248	<note>
140		249	You no longer have to <c>source</c> the profile for updates to the user/system
		250	VM take place.
		251	</note>
		252
141	</body>	253	</body>
142	</section>	254	</section>
		255	<section id="build-only">
		256	<title>Build Only VM</title>
		257	<body>
143		258
		259	<p>
		260	Some virtual machines are flagged as build-only due to being EOL and/or
		261	containing security vulnerabilities. These virtual machines will not
		262	automatically be used by Gentoo for the running of applications using Gentoo
		263	launchers but will still be available for use by Gentoo's build environment as
		264	some packages may require them for building. The setting of these virtual
		265	machines as either your system or user VM is strongly discouraged as these VMs
		266	will then be used when running the <path>/usr/bin/{java,javac,..}</path>
		267	executables and will also be used by any packages not using Gentoo's launcher
		268	scripts.
		269	</p>
		270
		271	</body>
		272	</section>
		273	<section id="preferred-vm">
		274	<title>Preferred VM</title>
		275	<body>
		276
		277	<p>
		278	While merging Java packages, the VM can and will be switched as necessary.
		279	</p>
		280
		281	<p>
		282	Because of the wide variety of available VMs, we do not have the resources to
		283	test and verify every package works on all of them. So to ensure that every
		284	packages merges smoothly, we have defined a list of <e>default/supported
		285	VMs</e> per arch. You can find them in
		286	<path>/usr/share/java-config-2/config/jdk-defaults.conf</path>. When you are
		287	merging a Java package, and it detects one of the VM in that file is installed,
		288	it will automatically use that VM, instead of the system-vm.
		289	</p>
		290
		291	<p>
		292	The merge time VM switching is also needed when, for example, your system-vm is
		293	set a 1.4 VM and the package you are merging requires a 1.5 VM. While merging
		294	it will use the preferred 1.5 VM, leaving your system-vm choice intact.
		295	</p>
		296
		297	<p>
		298	Of course, Gentoo is all about choice, so you can override these defaults in
		299	<path>/etc/java-config-2/build/jdk.conf</path> and have complete control over
		300	which VM will get used. Some examples:
		301	</p>
		302
		303	<pre caption="Example /etc/java-config-2/build/jdk.conf">
		304	<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>
		305	*=sun-jdk
		306	</pre>
		307
		308	<pre caption="Example /etc/java-config-2/build/jdk.conf">
		309	<comment>(Always use sun-jdk-1.5 wherever possible, except for when a 1.4 or 1.3 VM is explicitly required)</comment>
		310	*=sun-jdk-1.5
		311	</pre>
		312
		313	<pre caption="Example /etc/java-config-2/build/jdk.conf">
		314	<comment># For 1.3 I prefer sun-jdk 1.4 but when it is not available, use ibm-jdk-bin,
		315	# For 1.4, use blackdown-jdk, and for 1.5, use sun-jdk </comment>
		316	1.3=sun-jdk-1.4 ibm-jdk-bin
		317	1.4=blackdown-jdk
		318	1.5=sun-jdk
		319	</pre>
		320
		321	<warn>
		322	You do not have to edit this file. If you change these options to use a
		323	unsupported VM, things could possibly break. Bugs reported with a unsupported
		324	VM won't be prioritized as much as bugs present within supported VMs.
		325	</warn>
		326
		327	</body>
		328	</section>
		329	</chapter>
		330
		331	<chapter>
		332	<title>Compilers</title>
144	<section>	333	<section>
		334	<body>
		335
		336	<p>
		337	The standard Java compiler used for building is javac, which comes with each
		338	JDK. In addition to configuring the VM used at build time, it is also possible
		339	configure which compiler is used. Essentially, you define a list your
		340	preference for which compiler to use in
		341	<path>/etc/java-config-2/build/compilers.conf</path>.
		342	</p>
		343
		344	<pre caption="/etc/java-config-2/build/compilers.conf">
		345	# If the ebuild supports it
		346	# it will check the COMPILERS var front to back and
		347	# use the first compiler that is installed
		348
		349	COMPILERS="ecj-3.1 jikes javac"
		350	</pre>
		351
		352	<p>
		353	Some compilers don't support all possible -target and -source arguments.
		354	Therefore, each compiler in the list is checked to see if it can support the
		355	desired -source/-target. javac will work in all cases, so if no other suitable
		356	compiler is found, it will be used instead.
		357	</p>
		358
		359	<p>
		360	More details about each compiler are provided below:
		361	</p>
		362
		363	<table>
		364	<tr>
		365	<th>Name</th>
		366	<th>Handle</th>
		367	<th>Package</th>
		368	<th>Description</th>
		369	</tr>
		370	<tr>
		371	<ti>javac</ti>
		372	<ti>javac</ti>
		373	<ti>N/A</ti>
		374	<ti>
		375	This is the default compiler that will be used, and comes with each JDK.
		376	</ti>
		377	</tr>
		378	<tr>
		379	<ti>jikes</ti>
		380	<ti>jikes</ti>
		381	<ti>dev-java/jikes</ti>
		382	<ti>
		383	Jikes was originally developed by IBM. Anecdotally, it is generally quicker
		384	than javac. Note however, that it is more pedantic, and will fail under a
		385	few circumstances where javac has no issue. It also does not support Java
		386	1.5 syntax yet.
		387	</ti>
		388	</tr>
		389	<tr>
		390	<ti>Eclipse Compiler for Java</ti>
		391	<ti>ecj-3.1</ti>
		392	<ti>=dev-java/eclipse-ecj-3.1*</ti>
		393	<ti>
		394	ECJ is the compiler used by the Eclipse software development kit. It is
		395	very full featured, and is pretty fast. It does support Java 1.5 syntax.
		396	</ti>
		397	</tr>
		398	</table>
		399
		400	</body>
		401	</section>
		402	</chapter>
		403
		404	<chapter>
145	<title>Setting a default CLASSPATH</title>	405	<title>Setting a default CLASSPATH</title>
		406	<section>
146	<body>	407	<body>
147		408
		409	<warn>
		410	The options explained in this section should be considered deprecated and will
		411	most likely be removed in the future. We strongly recommend against using
		412	these, because your Java projects or application should ideally manage their
		413	own classpaths. If you choose to specify a default CLASSPATH, some applications
		414	may behave unexpectedly, because classes they weren't expecting would be on the
		415	classpath.
		416	</warn>
		417
		418	<p>
148	<p><c>java-config</c> can also be used to set a system-wide default	419	<c>java-config</c> can also be used to set a system-wide default CLASSPATH, as
149	CLASSPATH, and of course a user-specific default CLASSPATH.	420	well a user-specific default CLASSPATH.
150	</p>	421	</p>
151		422
152	<p>First you want to list available java libraries that might be	423	<p>
153	interesting to put in your CLASSPATH, thus:	424	First, you will want to list available Java libraries installed on your system
154	</p>	425	that might want to be put in your CLASSPATH. Here is an example of output:
155		426	</p>
		427
156	<pre caption = "Listing classes">	428	<pre caption="Listing classes">
157	[%1 ~] java-config --list-available-packages	429	# <i>java-config --list-available-packages</i>
158	[ant] No description (/usr/share/ant/classpath.env)	430	[xerces-2] The next generation of high performance, fully compliant XML parsers in the Apache Xerces family (/usr/share/xerces-2/package.env)
159	[java-gnome] No description (/usr/share/java-gnome/classpath.env)	431	[junit] Simple framework to write repeatable tests (/usr/share/junit/package.env)
160	[java-gtk] No description (/usr/share/java-gtk/classpath.env)	432	[bsh] BeanShell: A small embeddable Java source interpreter (/usr/share/bsh/package.env)
161	[log4j] "" (/usr/share/log4j/package.env)	433	[bcel] The Byte Code Engineering Library: analyze, create, manipulate Java class files (/usr/share/bcel/package.env)
		434	[log4j] A low-overhead robust logging package for Java (/usr/share/log4j/package.env)
		435	...
162	</pre>	436	</pre>
163		437
164	<note>None of these packages have a proper description. That is	438	<p>
165	something that will be implemented in the not-so-distant
166	future.
167	</note>
168
169	<p>Again, the name in brackets <path>"[]"</path> are the IDs that you	439	Again, the names in brackets (<e>[]</e>) are the IDs that you have to pass to
170	have to pass to <c>java-config --set-system-classpath</c>, thus:	440	<c>java-config --set-system-classpath</c>. Here is an example:
171	</p>	441	</p>
172		442
173	<pre caption = "Setting classpaths">	443	<pre caption="Setting classpaths">
174	java-config --set-system-classpath=log4j,java-gtk,java-gnome	444	# <i>java-config --set-system-classpath log4j,xerces-2</i>
175	</pre>	445	</pre>
176		446
		447	<note>
177	<note>The current directory (.) will not be part of the system classpath,	448	The current directory (<path>.</path>) will not be part of the system
178	as that should be added in root's login profile.	449	classpath, as that should be added in your system's login profile.
179	</note>	450	</note>
180		451
181	<p>Again, you will want to run <c>env-update</c> to update your	452	<p>
182	system's environment, and you might also want to relogin or resource	453	You will have to update your environment by logging out, then in again or
183	the <path>/etc/profile</path>.	454	sourcing <path>/etc/profile</path>.
184	</p>	455	</p>
185		456
		457	<p>
186	<p>For users, <c>java-config --set-user-classpath</c> will create	458	For users, <c>java-config --set-user-classpath</c> will create
187	<path>$HOME/.gentoo/java-env-classpath</path>, which is automatically	459	<path>~/.gentoo/java-env-classpath</path>, which you should then source from
188	included by <path>$HOME/.gentoo/java-env</path>.	460	your shell's profile.
189	</p>	461	</p>
190		462
		463	<pre caption="Sourcing user specific classpath">
		464	<i>if [[ -f "${HOME}/.gentoo/java-env-classpath" ]]; then
		465	source ${HOME}/.gentoo/java-env-classpath
		466	fi</i>
		467	</pre>
		468
		469	<p>
		470	If you really want a system wide or user default classpath you can add
		471	something like the following to your shell's profile. But we would advise
		472	against it.
		473	</p>
		474
		475	<pre caption="Setting classpath">
		476	# <i>export CLASSPATH="${CLASSPATH}:$(java-config --classpath log4j,xerces-2)"</i>
		477	</pre>
		478
191	</body>	479	</body>
192	</section>	480	</section>
193	</chapter>	481	</chapter>
194		482
195	<chapter>	483	<chapter>
		484	<title>Java Browser Plugins</title>
		485	<section>
		486	<title>Installing a plugin</title>
		487	<body>
		488
		489	<p>
		490	You can install a Java plugin for your web browser by emerging a Java VM with
		491	the <c>nsplugin</c> USE flag set.
		492	</p>
		493
		494	<note>
		495	<c>nsplugin</c> is not available for all architectures. Check for available
		496	plugins on your arch before trying to install a VM by running <c>emerge -pv
		497	<java-vm></c>.
		498	</note>
		499
		500	<p>
		501	Portage will allow you to install multiple versions of Java plugins, though
		502	only one will be used by your browser. You can check the list of available
		503	plugins by running:
		504	</p>
		505
		506	<pre caption="Viewing available plugins">
		507	# <i>eselect java-nsplugin list</i>
		508	[1] sun-jre-bin-1.6
		509	[2] icedtea6-bin
		510	</pre>
		511
		512	<p>
		513	In this example, <c>sun-jre-bin</c> is selected for the browser plugin.
		514	</p>
		515
		516	<pre caption="Selecting a plugin">
		517	# <i>eselect java-nsplugin set sun-jre-bin-1.6</i>
		518	</pre>
		519
		520	<p>
		521	Verify that the correct plugin was selected:
		522	</p>
		523
		524	<pre caption="Verifying the correct plugin">
		525	# <i>eselect java-nsplugin list</i>
		526	[1] sun-jre-bin-1.6 current
		527	[2] icedtea6-bin
		528	</pre>
		529
		530	<p>
		531	Java.com also provides a link to <uri
		532	link="http://java.com/en/download/installed.jsp">verify your installed
		533	plugin</uri>. Additionally, if you are using a Mozilla-based browser, you can
		534	verify your Java plugin by typing <c>about:plugins</c> into the address bar.
		535	</p>
		536
		537	</body>
		538	</section>
		539	<section>
		540	<title>Plugins on multilib systems</title>
		541	<body>
		542
		543	<p>
		544	If you are running a mixed 64-bit and 32-bit multilib system (for example, on
		545	AMD64), you can use 64-bit and 32-bit Java plugins. Unless you have a pressing
		546	need to run 32-bit Java applications, we recommend using native 64-bit plugins
		547	on 64-bit web browsers.
		548	</p>
		549
		550	<p>
		551	There are several native 64-bit browser plugins available. The default JDK/JRE
		552	pair, <c>sun-jdk</c> and <c>sun-jre-bin</c>, both include browser plugins. Just
		553	emerge one of them with the <c>nsplugin</c> USE flag enabled.
		554	</p>
		555
		556	<pre caption="Installing a 64-bit plugin">
		557	# <i>echo "dev-java/sun-jre-bin nsplugin" >> /etc/portage/package.use</i>
		558	# <i>emerge sun-jre-bin</i>
		559	</pre>
		560
		561	<p>
		562	To use a 32-bit plugin on a 32-bit browser, you will need to emerge
		563	<c>emul-linux-x86-java</c> with the <c>nsplugin</c> USE flag enabled.
		564	</p>
		565
		566	<pre caption="Installing a 32-bit plugin">
		567	# <i>echo "app-emulation/emul-linux-x86-java nsplugin" >> /etc/portage/package.use</i>
		568	# <i>emerge emul-linux-x86-java</i>
		569	</pre>
		570
		571	<p>
		572	Next, check which plugins are available:
		573	</p>
		574
		575	<pre caption="Viewing available plugins">
		576	# <i>eselect java-nsplugin list</i>
		577	Available 32-bit Java browser plugins
		578	[1] emul-linux-x86-java-1.5
		579	[2] emul-linux-x86-java-1.6
		580	Available 64-bit Java browser plugins
		581	[1] icedtea6-bin
		582	[2] sun-jre-bin-1.6
		583	</pre>
		584
		585	<p>
		586	Now select the right plugin for your browsers:
		587	</p>
		588
		589	<pre caption="Selecting plugins">
		590	<comment>(Choose the plugins for 32-bit and 64-bit browsers)</comment>
		591	# <i>eselect java-nsplugin set 32bit emul-linux-x86-java-1.6</i>
		592	# <i>eselect java-nsplugin set 64bit sun-jre-bin-1.6</i>
		593	</pre>
		594
		595	<p>
		596	Verify the correct plugin was selected:
		597	</p>
		598
		599	<pre caption="Verifying the correct plugin">
		600	# <i>eselect java-nsplugin list</i>
		601	Available 32-bit Java browser plugins
		602	[1] emul-linux-x86-java-1.5
		603	[2] emul-linux-x86-java-1.6 current
		604	Available 64-bit Java browser plugins
		605	[1] icedtea6-bin
		606	[2] sun-jre-bin-1.6 current
		607	</pre>
		608
		609	</body>
		610	</section>
		611	</chapter>
		612
		613	<chapter>
		614	<title>USE flags for use with Java</title>
		615	<section>
		616	<title>Setting USE flags</title>
		617	<body>
		618
		619	<p>
		620	For more information regarding USE flags, refer to the <uri
		621	link="/doc/en/handbook/handbook-x86.xml?part=2&chap=2">USE flags</uri>
		622	chapter from the Gentoo Handbook.
		623	</p>
		624
		625	</body>
		626	</section>
		627	<section>
		628	<title>The flags</title>
		629	<body>
		630
		631	<ul>
		632	<li>The <b>java</b> flag adds support for Java in a variety of programs</li>
		633	<li>
		634	The <b>nsplugin</b> flag adds support for Mozilla-like browsers (including
		635	Firefox). You will need this for viewing Java applets in your Mozilla-like
		636	browser.
		637	</li>
		638	<li>
		639	The <b>source</b> flag installs a zip of the source code of a package.
		640	This is traditionally used for IDEs to 'attach' source to the libraries you
		641	are using.
		642	</li>
		643	<li>The <b>jce</b> flag adds support for the Java Cryptography Engine</li>
		644	<li>
		645	For Java packages, the <b>doc</b> flag will build API documentation using
		646	javadoc.
		647	</li>
		648	</ul>
		649
		650	</body>
		651	</section>
		652	</chapter>
		653
		654	<chapter>
196	<title>Additional resources</title>	655	<title>Additional resources</title>
197	<section>	656	<section>
198	<title>Off-line resources</title>	657	<title>Off-line resources</title>
199
200	<body>	658	<body>
201		659
202	<ul>	660	<ul>
203	<li>java-config man page</li>	661	<li>java-config man page</li>
204	<li><c>java-config --help</c></li>	662	<li><c>java-config --help</c></li>
205	<li>The <path>/usr/bin/java-config</path> script itself</li>
206	</ul>	663	</ul>
207		664
208	</body>	665	</body>
209	</section>	666	</section>
210
211	<section>	667	<section>
212	<title>Online resources</title>	668	<title>Online resources</title>
213
214	<body>	669	<body>
215		670
216	<ul>	671	<ul>
217	<li>The <uri link="http://lists.gentoo.org/pipermail/gentoo-dev/">	672	<li>
218	gentoo-dev </uri>,	673	The <uri link="http://www.gentoo.org/proj/en/java/">Java Project
219	<uri link="http://lists.gentoo.org/pipermail/gentoo-user/"> gentoo-user	674	Page</uri>
220	</uri> mailing list archives</li>	675	</li>
221	<li>#gentoo on irc.openprojects.net</li>	676	<li>
		677	The <uri
		678	link="http://news.gmane.org/gmane.linux.gentoo.java">gentoo-java</uri>,
		679	<uri
		680	link="http://news.gmane.org/gmane.linux.gentoo.user">gentoo-user</uri>, and
		681	<uri
		682	link="http://news.gmane.org/gmane.linux.gentoo.devel">gentoo-dev</uri>
		683	mailing list archives
		684	</li>
		685	<li>
		686	<uri link="irc://irc.gentoo.org/gentoo">#gentoo</uri> and <uri
		687	link="irc://irc.gentoo.org/gentoo-java">#gentoo-java</uri> on IRC
		688	</li>
		689	<li>
		690	<uri
		691	link="http://en.wikipedia.org/wiki/Java_programming_language">Wikipedia's
		692	entry for Java</uri>
		693	</li>
		694	<li>
		695	If you have suggestions or questions regarding this document, please email
		696	the Gentoo Java team: <mail>java@gentoo.org</mail>
		697	</li>
222	</ul>	698	</ul>
223		699
224	</body>	700	</body>
225	</section>	701	</section>
226	</chapter>	702	</chapter>
227
228	<chapter>
229	<title>Caveats</title>
230	<section>
231	<title>General</title>
232
233	<body>
234
235	<p>If you select a JRE as your default VM, you may not have a
236	<c>javac</c> command handy at all times, unless you have manually
237	installed a symlink to take care of that.
238	</p>
239
240	<p>Jikes will be used to compile some of the largest packages, if it
241	is available. With time, we hope to be able to compile all
242	java-dependent packages with Jikes, so some dependencies on the JDK
243	can be replaced with a dependency on the JRE.</p>
244
245	<p>With some versions of Portage, doing an <c>emerge --world
246	update</c> will install the JDK regardless if whether you have it
247	installed before or not. This is a known bug addressed in later
248	versions of Portage.
249	</p>
250
251	</body>
252	</section>
253	</chapter>
254	</guide>	703	</guide>

 Legend:



Removed from v.1.4
 


changed lines


 
Added in v.1.44
 Legend:



Removed from v.1.4
 


changed lines


 
Added in v.1.44
-Removed from v.1.4
+Added in v.1.44

	ViewVC Help
Powered by ViewVC 1.1.13