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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<!-- $Header: /var/cvsroot/gentoo/xml/htdocs/doc/en/java.xml,v 1.42 2008/09/28 20:29:25 nightmorph Exp $ -->
3<guide> 3<!DOCTYPE guide SYSTEM "/dtd/guide.dtd">
4
5<guide link="/doc/en/java.xml">
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>
10Users' and Developers' Guide to Java in Gentoo 19This guide will introduce you to Java and explain how to use Java with Gentoo
20Linux.
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>0.17</version>
14<date>June 25, 2002</date> 28<date>2008-09-28</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
23Blackdown JDK/JRE pair, as it is freely (beer) available without any
24registration fuss.</p>
25 35
26<note>As kaffe becomes a JRE/JDK drop-in replacement, that will most 36<p>
27likely become our default.</note> 37Java is a programming language developed by engineers of Sun Microsystems. The
38language is object-oriented and designed to run on multiple platforms without
39the need of recompiling code for each platform. Although Java can be compiled
40as a native program, much of Java's popularity can be attributed to its
41portability, along with other features such as garbage collection. To make
42platform independence possible the Java compiler compiles the Java code to an
43intermediate representation called "Java bytecode" that runs on a JRE (Java
44Runtime 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>
30getting them is a bit more work, as you are required to read and 48In order to run Java bytecode, one needs to have a JRE (Java Runtime
31accept their license before downloading (IBM additionally requires you 49Environment) installed. A JRE provides core libraries, a platform dependent
32to register).</p> 50Java Virtual Machine, plugins for browsers, among other things. A JDK (Java
51Development Kit) adds programming tools, such as a bytecode compiler and a
52debugger.
53</p>
33 54
34<p>Our ebuilds for the Sun and IBM JDK/JREs will notify you of where
35to 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>Before You Begin</title>
61<section>
62<title>Existing installs</title>
63<body>
64
65<p>
66For existing installs, regardless of if you have installed anything Java
67before, make sure you have followed the <uri
68link="/proj/en/java/java-upgrade.xml">Java Upgrade Guide</uri>.
69</p>
70
41<body> 71</body>
42<p>If you run <c>emerge dev-java/sun-jdk-1.3.1</c> or <c>emerge 72</section>
43dev-java/ibm-jdk-1.3.1</c>, you will be notified that you are required 73<section>
44to download the actual tarballs yourself. This has to do with license 74<title>New installs</title>
45restrictions for the Sun JDK/JRE (online click-wrap license) and 75<body>
46registration issues with the IBM JDK/JRE.</p>
47 76
48<note>There is also a dev-java/sun-jdk-1.4.0, but not all packages 77<p>
49work nicely with Java 1.4, so you're on your own if you use the 1.4.0 78New 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>
92Gentoo 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<!--
124TODO: list free implementations?
125note about not drop-in replacements
126kaffe/sablevm/gcj/jamvm
127-->
128<p>
129The default for Java 1.4 is the Blackdown JRE/JDK pair, as it is freely
130("free as in beer") available without any registration fuss.
131</p>
132
133<p>
134JREs and JDKs from Sun, IBM, and BEA are generally faster, but getting them
135is a bit more work, as you are required to read and accept their license before
136downloading (IBM additionally requires you to register).
137</p>
138
139</body>
140</section>
141<section>
142<title>Installing a JRE/JDKs</title>
143<body>
144
145<p>
146To install your profile's default JDK, you can run <c>emerge virtual/jdk</c>.
147Or to install your profile's default JRE, you can <c>emerge virtual/jre</c>.
148</p>
149
150<p>
151In recent events, Sun has relicensed their JDK and JRE under a more Linux
152distro friendly license. As a result, Sun releases Java 1.5 and onwards are
153freely downloadable, without any further hassle.
154</p>
155
156<note>
157A JDK also includes a JRE, so if you install a JDK you shouldn't have to also
158have to install a JRE.
50JDK.</note> 159</note>
51 160
161</body>
162</section>
163<section>
164<title>Installing fetch-restricted virtual machines</title>
165<body>
166
167<p>
168As already mentioned, some of the JDKs and JREs require you to jump through a
169few hoops before installing. Simply emerge the packages as you normally would.
170The ebuilds will then instruct you where to go and what to download.
171</p>
172
173<p>
52<p>You should download the indicated file(s) into 174You should download the indicated file(s) into
53<path>/usr/portage/distfiles</path>. Once that is done, you can rerun 175<path>/usr/portage/distfiles</path>. Once there, you can rerun the emerge
54the emerge command, then the JDK/JRE will be installed properly into 176command, at which point the JRE/JDK will be begin to install.
55<path>/opt</path>.</p> 177</p>
56</body>
57</section>
58</chapter>
59 178
179</body>
180</section>
60<chapter> 181</chapter>
61<title>Configuring your JDK/JRE</title> 182
183<chapter>
184<title>Configuring your virtual machine</title>
62<section> 185<section>
63<title>Overview</title> 186<title>Overview</title>
64<body> 187<body>
188
189<p>
65<p>Gentoo has the ability to have multiple JDKs and JREs installed 190Gentoo has the ability to have multiple JDKs and JREs installed without causing
66without them conflicting. There are a few caveats to this, as noted 191conflicts.
67below.</p> 192</p>
68 193
194<p>
69<p>Using the <c>java-config</c> tool, you can set the system-wide 195Using the <c>java-config</c> tool, you can set the system-wide default
70default if you have root access. Users can also use <c>java-config</c> 196(provided you have root access). Users can also use <c>java-config</c> to set
71to set up their own personal default, that is different from the 197up their own personal default.
72system-wide default.</p> 198</p>
73</body>
74</section>
75 199
200<note>
201You can also use <e>eselect</e> to change the system and user vm. See
202<c>eselect java-vm help</c>.
203</note>
204
205</body>
76<section> 206</section>
207<section>
77<title>Setting a default JDK/JRE</title> 208<title>Setting a default virtual machine</title>
78<body> 209<body>
210
211<p>
79<p>Running the command <c>java-config --list-available-vms</c> will 212Running the command <c>java-config --list-available-vms</c> will give you a
80give you a list of all availble JREs and JDKs on your system, thus:</p> 213list of all JREs and JDKs installed on your system. Here is an example of
214output:
215</p>
216
217<pre caption="Listing available VMs">
218# <i>java-config --list-available-vms</i>
219The following VMs are available for generation-2:
2201) Blackdown JDK 1.4.2.03 [blackdown-jdk-1.4.2]
2212) Blackdown JRE 1.4.2.03 [blackdown-jre-1.4.2]
2223) Blackdown 32bit JRE 1.4.2.03 [emul-linux-x86-java-1.4.2]
2234) Sun 32bit JRE 1.5.0.08 [emul-linux-x86-java-1.5]
2245) Kaffe 1.1.7 [kaffe]
225*) Sun JDK 1.5.0.08 [sun-jdk-1.5]
81<pre> 226</pre>
82[%1 ~] java-config --list-available-vms 227
83[blackdown-jdk-1.3.1] Blackdown JDK 1.3.1 (/etc/env.d/java/20blackdown-jdk-1.3.1) 228<p>
84[blackdown-jre-1.3.1] Blackdown JRE 1.3.1 (/etc/env.d/java/20blackdown-jre-1.3.1) 229The <e>*</e> indicates this is the current active vm (system-vm or user-vm when
85[ibm-jdk-1.3.0] IBM JDK 1.3.0 (/etc/env.d/java/20ibm-jdk-1.3.0)
86[ibm-jdk-1.3.1] IBM JDK 1.3.1 (/etc/env.d/java/20ibm-jdk-1.3.1)
87[ibm-jre-1.3.1] IBM JRE 1.3.1 (/etc/env.d/java/20ibm-jre-1.3.1)
88[sun-jdk-1.4.0] Sun JDK 1.4.0 (/etc/env.d/java/20sun-jdk-1.4.0)
89</pre>
90<p>The name in the brackets <path>"[]"</path> is the handle or ID for 230set). The name in the brackets (<e>[]</e>) is the handle or ID for that
91that particular VM. You use pass that ID to <c>java-config 231particular VM. You use the handle or the number to <c>java-config
92--set-system-vm</c>, thus:</p> 232--set-system-vm</c>. Here is an example of how to set the system VM.
233</p>
234
235<pre caption="Setting the System VM">
236<comment>(By handle (preferred))</comment>
237# <i>java-config --set-system-vm blackdown-jdk-1.4</i>
238Now using blackdown-jdk-1.4 as your generation-2 system JVM
239<comment>(By number)</comment>
240# <i>java-config --set-system-vm 6</i>
241Now using sun-jdk-1.5 as your generation-2 system JVM
93<pre> 242</pre>
94[#1 ~] java-config --set-system-vm=ibm-jdk-1.3.1
95Now using IBM JDK 1.3.1 (/etc/env.d/java/20ibm-jdk-1.3.1)
96</pre>
97 243
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
101particular VM ID, you will need to regenerate your /etc/profile.env,
102thus:</p>
103<pre> 244<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>, 245As a regular user, you can use <c>java-config --set-user-vm</c>.
111which will create <path>$HOME/.gentoo/java-env</path> with all 246</p>
112required env vars. You would normally source this from your shell's
113startup script (<path>$HOME/.zshenv</path> in my case).</p>
114</body>
115</section>
116 247
248<note>
249You no longer have to <c>source</c> the profile for updates to the user/system
250VM take place.
251</note>
252
253</body>
117<section> 254</section>
255<section id="preferred-vm">
256<title>Preferred VM</title>
257<body>
258
259<p>
260While merging Java packages, the VM can and will be switched as necessary.
261</p>
262
263<p>
264Because of the wide variety of available VMs, we do not have the resources to
265test and verify every package works on all of them. So to ensure that every
266packages merges smoothly, we have defined a list of <e>default/supported
267VMs</e> per arch. You can find them in
268<path>/usr/share/java-config-2/config/jdk-defaults.conf</path>. When you are
269merging a Java package, and it detects one of the VM in that file is installed,
270it will automatically use that VM, instead of the system-vm.
271</p>
272
273<p>
274The merge time VM switching is also needed when, for example, your system-vm is
275set a 1.4 VM and the package you are merging requires a 1.5 VM. While merging
276it will use the preferred 1.5 VM, leaving your system-vm choice intact.
277</p>
278
279<p>
280Of course, Gentoo is all about choice, so you can override these defaults in
281<path>/etc/java-config-2/build/jdk.conf</path> and have complete control over
282which VM will get used. Some examples:
283</p>
284
285<pre caption="Example /etc/java-config-2/build/jdk.conf">
286<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>
287*=sun-jdk
288</pre>
289
290<pre caption="Example /etc/java-config-2/build/jdk.conf">
291<comment>(Always use sun-jdk-1.5 wherever possible, except for when a 1.4 or 1.3 VM is explicitly required)</comment>
292*=sun-jdk-1.5
293</pre>
294
295<pre caption="Example /etc/java-config-2/build/jdk.conf">
296<comment># For 1.3 I prefer sun-jdk 1.4 but when it is not available, use ibm-jdk-bin,
297# For 1.4, use blackdown-jdk, and for 1.5, use sun-jdk </comment>
2981.3=sun-jdk-1.4 ibm-jdk-bin
2991.4=blackdown-jdk
3001.5=sun-jdk
301</pre>
302
303<warn>
304You do not have to edit this file. If you change these options to use a
305unsupported VM, things could possibly break. Bugs reported with a unsupported
306VM won't be prioritized as much as bugs present within supported VMs.
307</warn>
308
309</body>
310</section>
311</chapter>
312
313<chapter>
314<title>Compilers</title>
315<section>
316<body>
317
318<p>
319The standard Java compiler used for building is javac, which comes with each
320JDK. In addition to configuring the VM used at build time, it is also possible
321configure which compiler is used. Essentially, you define a list your
322preference for which compiler to use in
323<path>/etc/java-config-2/build/compilers.conf</path>.
324</p>
325
326<pre caption="/etc/java-config-2/build/compilers.conf">
327# If the ebuild supports it
328# it will check the COMPILERS var front to back and
329# use the first compiler that is installed
330
331COMPILERS="ecj-3.1 jikes javac"
332</pre>
333
334<p>
335Some compilers don't support all possible -target and -source arguments.
336Therefore, each compiler in the list is checked to see if it can support the
337desired -source/-target. javac will work in all cases, so if no other suitable
338compiler is found, it will be used instead.
339</p>
340
341<p>
342More details about each compiler are provided below:
343</p>
344
345<table>
346<tr>
347 <th>Name</th>
348 <th>Handle</th>
349 <th>Package</th>
350 <th>Description</th>
351</tr>
352<tr>
353 <ti>javac</ti>
354 <ti>javac</ti>
355 <ti>N/A</ti>
356 <ti>
357 This is the default compiler that will be used, and comes with each JDK.
358 </ti>
359</tr>
360<tr>
361 <ti>jikes</ti>
362 <ti>jikes</ti>
363 <ti>dev-java/jikes</ti>
364 <ti>
365 Jikes was originally developed by IBM. Anecdotally, it is generally quicker
366 than javac. Note however, that it is more pedantic, and will fail under a
367 few circumstances where javac has no issue. It also does not support Java
368 1.5 syntax yet.
369 </ti>
370</tr>
371<tr>
372 <ti>Eclipse Compiler for Java</ti>
373 <ti>ecj-3.1</ti>
374 <ti>=dev-java/eclipse-ecj-3.1*</ti>
375 <ti>
376 ECJ is the compiler used by the Eclipse software development kit. It is
377 very full featured, and is pretty fast. It does support Java 1.5 syntax.
378 </ti>
379</tr>
380</table>
381
382</body>
383</section>
384</chapter>
385
386<chapter>
118<title>Setting a default CLASSPATH</title> 387<title>Setting a default CLASSPATH</title>
388<section>
119<body> 389<body>
390
391<warn>
392The options explained in this section should be considered deprecated and will
393most likely be removed in the future. We strongly recommend against using
394these, because your Java projects or application should ideally manage their
395own classpaths. If you choose to specify a default CLASSPATH, some applications
396may behave unexpectedly, because classes they weren't expecting would be on the
397classpath.
398</warn>
399
400<p>
120<p><c>java-config</c> can also be used to set a system-wide default 401<c>java-config</c> can also be used to set a system-wide default CLASSPATH, as
121CLASSPATH, and of course a user-specific default CLASSPATH.</p> 402well a user-specific default CLASSPATH.
403</p>
122 404
123<p>First you want to list available java libraries that might be 405<p>
124interesting to put in your CLASSPATH, thus:</p> 406First, you will want to list available Java libraries installed on your system
407that might want to be put in your CLASSPATH. Here is an example of output:
408</p>
409
410<pre caption="Listing classes">
411# <i>java-config --list-available-packages</i>
412[xerces-2] The next generation of high performance, fully compliant XML parsers in the Apache Xerces family (/usr/share/xerces-2/package.env)
413[junit] Simple framework to write repeatable tests (/usr/share/junit/package.env)
414[bsh] BeanShell: A small embeddable Java source interpreter (/usr/share/bsh/package.env)
415[bcel] The Byte Code Engineering Library: analyze, create, manipulate Java class files (/usr/share/bcel/package.env)
416[log4j] A low-overhead robust logging package for Java (/usr/share/log4j/package.env)
417...
125<pre> 418</pre>
126[%1 ~] java-config --list-available-packages 419
127[ant] No description (/usr/share/ant/classpath.env) 420<p>
128[java-gnome] No description (/usr/share/java-gnome/classpath.env) 421Again, 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) 422<c>java-config --set-system-classpath</c>. Here is an example:
130[log4j] "" (/usr/share/log4j/package.env)
131</pre> 423</p>
132 424
133<note>None of these packages have a proper description. That is 425<pre caption="Setting classpaths">
134something that will be implemented in the not-so-distant 426# <i>java-config --set-system-classpath log4j,xerces-2</i>
135future.</note>
136
137<p>Again, the name in brackets <path>"[]"</path> are the IDs that you
138have to pass to <c>java-config --set-system-classpath</c>, thus:</p>
139<pre> 427</pre>
140java-config --set-system-classpath=log4j,java-gtk,java-gnome 428
429<note>
430The current directory (<path>.</path>) will not be part of the system
431classpath, as that should be added in your system's login profile.
432</note>
433
434<p>
435You will have to update your environment by logging out, then in again or
436sourcing <path>/etc/profile</path>.
141</pre> 437</p>
142<note>The current directory (.) will not be part of the system classpath, 438
143as that should be added in root's login profile.</note> 439<p>
144<p>Again, you will want to run <c>env-update</c> to update your
145system's environment, and you might also want to relogin or resource
146the <path>/etc/profile</path>.</p>
147<p>For users, <c>java-config --set-user-classpath</c> will create 440For users, <c>java-config --set-user-classpath</c> will create
148<path>$HOME/.gentoo/java-env-classpath</path>, which is automatically 441<path>~/.gentoo/java-env-classpath</path>, which you should then source from
149included by <path>$HOME/.gentoo/java-env</path>.</p> 442your shell's profile.
443</p>
444
445<pre caption="Sourcing user specific classpath">
446<i>if [[ -f "${HOME}/.gentoo/java-env-classpath" ]]; then
447 source ${HOME}/.gentoo/java-env-classpath
448fi</i>
449</pre>
450
451<p>
452If you really want a system wide or user default classpath you can add
453something like the following to your shell's profile. But we would advise
454against it.
455</p>
456
457<pre caption="Setting classpath">
458# <i>export CLASSPATH="${CLASSPATH}:$(java-config --classpath log4j,xerces-2)"</i>
459</pre>
460
461</body>
462</section>
463</chapter>
464
465<chapter>
466<title>Java Browser Plugins</title>
467<section>
468<title>Installing a plugin</title>
469<body>
470
471<p>
472You can install a Java plugin for your web browser by emerging a Java VM with
473the <c>nsplugin</c> USE flag set.
474</p>
475
476<note>
477<c>nsplugin</c> is not available for all architectures. Check for available
478plugins on your arch before trying to install a VM by running <c>emerge -pv
479&lt;java-vm&gt;</c>.
480</note>
481
482<p>
483Portage will allow you to install multiple versions of Java plugins, though
484only one will be used by your browser. You can check the list of available
485plugins by running:
486</p>
487
488<pre caption="Viewing available plugins">
489# <i>eselect java-nsplugin list</i>
490 [1] sun-jre-bin-1.5
491 [2] blackdown-jre-1.4.2
492</pre>
493
494<p>
495In this example, <c>sun-jre-bin</c> is selected for the browser plugin.
496</p>
497
498<pre caption="Selecting a plugin">
499# <i>eselect java-nsplugin set sun-jre-bin-1.5</i>
500</pre>
501
502<p>
503Verify that the correct plugin was selected:
504</p>
505
506<pre caption="Verifying the correct plugin">
507# <i>eselect java-nsplugin list</i>
508 [1] sun-jre-bin-1.5 current
509 [2] blackdown-jre-1.4.2
510</pre>
511
512<p>
513Java.com also provides a link to <uri
514link="http://java.com/en/download/installed.jsp">verify your installed
515plugin</uri>. Additionally, if you are using a Mozilla-based browser, you can
516verify your Java plugin by typing <c>about:plugins</c> into the address bar.
517</p>
518
519</body>
520</section>
521<section>
522<title>Plugins on multilib systems</title>
523<body>
524
525<p>
526If you are running a mixed 64-bit and 32-bit multilib system (for example, on
527AMD64), you can only use 32-bit Java plugins.
528</p>
529
530<p>
531To use a 32-bit plugin, you will need to emerge <c>emul-linux-x86-java</c> with
532the <c>nsplugin</c> USE flag enabled.
533</p>
534
535<pre caption="Installing a 32-bit plugin">
536# <i>echo "app-emulation/emul-linux-x86-java nsplugin" >> /etc/portage/package.use</i>
537# <i>emerge emul-linux-x86-java</i>
538</pre>
539
540<p>
541Next, check which plugins are available:
542</p>
543
544<pre caption="Viewing available plugins">
545# <i>eselect java-nsplugin list</i>
546Available 32-bit Java browser plugins
547 [1] emul-linux-x86-java-1.4.2
548 [2] emul-linux-x86-java-1.5
549</pre>
550
551<p>
552Although you must select a 32-bit browser (such as <c>mozilla-firefox-bin</c>)
553to use with your 32-bit plugin, the 64-bit version of <c>konqueror</c> uses your
554Java VM directly, so it's possible to use the 64-bit version of <c>blackdown</c>
555with this browser; no further configuration is necessary.
556</p>
557
558<p>
559Now select the right plugin for your 32-bit browser:
560</p>
561
562<pre caption="Selecting plugins">
563# <i>eselect java-nsplugin set 32bit emul-linux-x86-java-1.5</i>
564</pre>
565
566<p>
567Verify the correct plugin was selected:
568</p>
569
570<pre caption="Verifying the correct plugin">
571# <i>eselect java-nsplugin list</i>
572Available 32-bit Java browser plugins
573 [1] emul-linux-x86-java-1.4.2
574 [2] emul-linux-x86-java-1.5 current
575</pre>
576
577</body>
578</section>
579</chapter>
580
581<chapter>
582<title>USE flags for use with Java</title>
583<section>
584<title>Setting USE flags</title>
585<body>
586
587<p>
588For more information regarding USE flags, refer to the <uri
589link="/doc/en/handbook/handbook-x86.xml?part=2&amp;chap=2">USE flags</uri>
590chapter from the Gentoo Handbook.
591</p>
592
593</body>
594</section>
595<section>
596<title>The flags</title>
597<body>
598
599<ul>
600 <li>The <b>java</b> flag adds support for Java in a variety of programs</li>
601 <li>
602 The <b>nsplugin</b> flag adds support for Mozilla-like browsers (including
603 Firefox). You will need this for viewing Java applets in your Mozilla-like
604 browser.
605 </li>
606 <li>
607 The <b>source</b> flag installs a zip of the source code of a package.
608 This is traditionally used for IDEs to 'attach' source to the libraries you
609 are using.
610 </li>
611 <li>The <b>jce</b> flag adds support for the Java Cryptography Engine</li>
612 <li>
613 For Java packages, the <b>doc</b> flag will build API documentation using
614 javadoc.
615 </li>
616</ul>
617
150</body> 618</body>
151</section> 619</section>
152</chapter> 620</chapter>
153 621
154<chapter> 622<chapter>
155<title>Additional resources</title> 623<title>Additional resources</title>
156<section> 624<section>
157<title>Off-line resources</title> 625<title>Off-line resources</title>
158<body> 626<body>
627
159<ul> 628<ul>
160<li>java-config man page</li> 629 <li>java-config man page</li>
161<li><c>java-config --help</c></li> 630 <li><c>java-config --help</c></li>
162<li>The <path>/usr/bin/java-config</path> script itself</li>
163</ul> 631</ul>
632
164</body> 633</body>
165</section> 634</section>
166<section> 635<section>
167<title>Online resources</title> 636<title>Online resources</title>
168<body> 637<body>
638
169<ul> 639<ul>
170<li>The <uri link="http://lists.gentoo.org/pipermail/gentoo-dev/"> 640 <li>
171gentoo-dev </uri>, 641 The <uri link="http://www.gentoo.org/proj/en/java/">Java Project
172<uri link="http://lists.gentoo.org/pipermail/gentoo-user/"> gentoo-user 642 Page</uri>
643 </li>
644 <li>
645 The <uri
646 link="http://news.gmane.org/gmane.linux.gentoo.java">gentoo-java</uri>,
647 <uri
648 link="http://news.gmane.org/gmane.linux.gentoo.user">gentoo-user</uri>, and
649 <uri
650 link="http://news.gmane.org/gmane.linux.gentoo.devel">gentoo-dev</uri>
173</uri> mailing list archives</li> 651 mailing list archives
174<li>#gentoo on irc.openprojects.net</li> 652 </li>
653 <li>
654 <uri link="irc://irc.gentoo.org/gentoo">#gentoo</uri> and <uri
655 link="irc://irc.gentoo.org/gentoo-java">#gentoo-java</uri> on IRC
656 </li>
657 <li>
658 <uri
659 link="http://en.wikipedia.org/wiki/Java_programming_language">Wikipedia's
660 entry for Java</uri>
661 </li>
662 <li>
663 If you have suggestions or questions regarding this document, please email
664 the Gentoo Java team: <mail>java@gentoo.org</mail>
665 </li>
175</ul> 666</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
186installed a symlink to take care of that.</p>
187 667
188<p>Jikes will be used to compile some of the largest packages, if it
189is available. With time, we hope to be able to compile all
190java-dependent packages with Jikes, so some dependencies on the JDK
191can be replaced with a dependency on the JRE.</p>
192
193<p>With some versions of Portage, doing an <c>emerge --world
194update</c> will install the JDK regardless if whether you have it
195installed before or not. This is a known bug addressed in later
196versions of Portage.</p>
197</body> 668</body>
198</section> 669</section>
199</chapter> 670</chapter>
200</guide> 671</guide>

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