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

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

Parent Directory Parent Directory | Revision Log Revision Log


Revision 1.9 - (show annotations) (download) (as text)
Sat Nov 15 00:35:19 2003 UTC (10 years, 10 months ago) by neysx
Branch: MAIN
Changes since 1.8: +1 -0 lines
File MIME type: application/xml
Added $Header$ cvs tag -- NO CONTENT CHANGE

1 <?xml version='1.0' encoding="UTF-8"?>
2 <!-- $Header$ -->
3 <!DOCTYPE guide SYSTEM "/dtd/guide.dtd">
4
5 <guide link = "/doc/en/java.xml">
6 <title>Gentoo Java Guide</title>
7 <author title="Author and Editor">
8 <mail link="karltk@gentoo.org">Karl Trygve Kalleberg</mail>
9 </author>
10
11 <abstract>
12 Users' and Developers' Guide to Java in Gentoo
13 </abstract>
14
15 <license/>
16
17 <version>0.1.2</version>
18 <date>September 4, 2002</date>
19
20 <chapter>
21 <title>Installing a JDK/JRE</title>
22 <section>
23 <title>Overview</title>
24 <body>
25
26 <p>Gentoo provides numerous JDKs and JREs. The default is the
27 Blackdown JDK/JRE pair, as it is freely (beer) available without any
28 registration fuss.
29 </p>
30
31 <note>As kaffe becomes a JRE/JDK drop-in replacement, that will most
32 likely become our default.
33 </note>
34
35 <p>Both the Sun JDK/JRE and the IBM JDK/JRE are generally faster, but
36 getting them is a bit more work, as you are required to read and
37 accept their license before downloading (IBM additionally requires you
38 to register).
39 </p>
40
41 <p>Our ebuilds for the Sun and IBM JDK/JREs will notify you of where
42 to go to download them.
43 </p>
44
45 </body>
46 </section>
47
48 <section>
49 <title>Installing the Sun/IBM JDK/JREs</title>
50 <body>
51
52 <p>If you run <c>emerge sun-jdk-1.3.1</c> or <c>emerge
53 ibm-jdk-1.3.1</c>, you will be notified that you are required
54 to download the actual tarballs yourself. This has to do with license
55 restrictions for the Sun JDK/JRE (online click-wrap license) and
56 registration issues with the IBM JDK/JRE.
57 </p>
58
59 <note>There is also a sun-jdk-1.4.0, but not all packages
60 work nicely with Java 1.4, so you're on your own if you use the 1.4.0
61 JDK.
62 </note>
63
64 <p>You should download the indicated file(s) into
65 <path>/usr/portage/distfiles</path>. Once that is done, you can rerun
66 the emerge command, then the JDK/JRE will be installed properly into
67 <path>/opt</path>.
68 </p>
69
70 </body>
71 </section>
72 </chapter>
73
74 <chapter>
75 <title>Configuring your JDK/JRE</title>
76
77 <section>
78 <title>Overview</title>
79
80 <body>
81
82 <p>Gentoo has the ability to have multiple JDKs and JREs installed
83 without them conflicting. There are a few caveats to this, as noted
84 below.
85 </p>
86
87 <p>Using the <c>java-config</c> tool, you can set the system-wide
88 default if you have root access. Users can also use <c>java-config</c>
89 to set up their own personal default, that is different from the
90 system-wide default.
91 </p>
92
93 </body>
94 </section>
95
96 <section>
97 <title>Setting a default JDK/JRE</title>
98 <body>
99
100 <p>Running the command <c>java-config --list-available-vms</c> will
101 give you a list of all availble JREs and JDKs on your system, thus:</p>
102
103 <pre caption = "Listing available VMs">
104 [%1 ~] java-config --list-available-vms
105 [blackdown-jdk-1.3.1] Blackdown JDK 1.3.1 (/etc/env.d/java/20blackdown-jdk-1.3.1)
106 [blackdown-jre-1.3.1] Blackdown JRE 1.3.1 (/etc/env.d/java/20blackdown-jre-1.3.1)
107 [ibm-jdk-1.3.0] IBM JDK 1.3.0 (/etc/env.d/java/20ibm-jdk-1.3.0)
108 [ibm-jdk-1.3.1] IBM JDK 1.3.1 (/etc/env.d/java/20ibm-jdk-1.3.1)
109 [ibm-jre-1.3.1] IBM JRE 1.3.1 (/etc/env.d/java/20ibm-jre-1.3.1)
110 [sun-jdk-1.4.0] Sun JDK 1.4.0 (/etc/env.d/java/20sun-jdk-1.4.0)
111 </pre>
112
113 <p>The name in the brackets <path>"[]"</path> is the handle or ID for
114 that particular VM. You use pass that ID to <c>java-config
115 --set-system-vm</c>, thus:
116 </p>
117
118 <pre caption = "Setting the System VM">
119 [#1 ~] java-config --set-system-vm=ibm-jdk-1.3.1
120 Now using IBM JDK 1.3.1 (/etc/env.d/java/20ibm-jdk-1.3.1)
121 </pre>
122
123 <note>You will have to be root to run --set-system-vm
124 </note>
125
126 <p>Once you have issued <c>java-config --set-system-vm</c> with a
127 particular VM ID, you will need to regenerate your /etc/profile.env,
128 thus:
129 </p>
130
131 <pre caption = "Regenerating /etc/profile.env" >
132 [#1 ~] env-update
133 </pre>
134
135 <p>After this, you will either want to relogin, or resource
136 <path>/etc/profile</path> into your environment.
137 </p>
138
139 <p>As a regular user, you can use <c>java-config --set-user-vm</c>,
140 which will create <path>$HOME/.gentoo/java-env</path> with all
141 required env vars. You would normally source this from your shell's
142 startup script (<path>$HOME/.zshenv</path> in my case).</p>
143
144 </body>
145 </section>
146
147 <section>
148 <title>Setting a default CLASSPATH</title>
149 <body>
150
151 <p><c>java-config</c> can also be used to set a system-wide default
152 CLASSPATH, and of course a user-specific default CLASSPATH.
153 </p>
154
155 <p>First you want to list available java libraries that might be
156 interesting to put in your CLASSPATH, thus:
157 </p>
158
159 <pre caption = "Listing classes">
160 [%1 ~] java-config --list-available-packages
161 [ant] No description (/usr/share/ant/classpath.env)
162 [java-gnome] No description (/usr/share/java-gnome/classpath.env)
163 [java-gtk] No description (/usr/share/java-gtk/classpath.env)
164 [log4j] "" (/usr/share/log4j/package.env)
165 </pre>
166
167 <note>None of these packages have a proper description. That is
168 something that will be implemented in the not-so-distant
169 future.
170 </note>
171
172 <p>Again, the name in brackets <path>"[]"</path> are the IDs that you
173 have to pass to <c>java-config --set-system-classpath</c>, thus:
174 </p>
175
176 <pre caption = "Setting classpaths">
177 java-config --set-system-classpath=log4j,java-gtk,java-gnome
178 </pre>
179
180 <note>The current directory (.) will not be part of the system classpath,
181 as that should be added in root's login profile.
182 </note>
183
184 <p>Again, you will want to run <c>env-update</c> to update your
185 system's environment, and you might also want to relogin or resource
186 the <path>/etc/profile</path>.
187 </p>
188
189 <p>For users, <c>java-config --set-user-classpath</c> will create
190 <path>$HOME/.gentoo/java-env-classpath</path>, which is automatically
191 included by <path>$HOME/.gentoo/java-env</path>.
192 </p>
193
194 </body>
195 </section>
196 </chapter>
197
198 <chapter>
199 <title>Additional resources</title>
200 <section>
201 <title>Off-line resources</title>
202
203 <body>
204
205 <ul>
206 <li>java-config man page</li>
207 <li><c>java-config --help</c></li>
208 <li>The <path>/usr/bin/java-config</path> script itself</li>
209 </ul>
210
211 </body>
212 </section>
213
214 <section>
215 <title>Online resources</title>
216
217 <body>
218
219 <ul>
220 <li>The <uri link="http://news.gmane.org/gmane.linux.gentoo.devel">
221 gentoo-dev </uri>,
222 <uri link="http://news.gmane.org/gmane.linux.gentoo.user"> gentoo-user
223 </uri> mailing list archives</li>
224 <li>#gentoo on irc.openprojects.net</li>
225 </ul>
226
227 </body>
228 </section>
229 </chapter>
230
231 <chapter>
232 <title>Caveats</title>
233 <section>
234 <title>General</title>
235
236 <body>
237
238 <p>If you select a JRE as your default VM, you may not have a
239 <c>javac</c> command handy at all times, unless you have manually
240 installed a symlink to take care of that.
241 </p>
242
243 <p>Jikes will be used to compile some of the largest packages, if it
244 is available. With time, we hope to be able to compile all
245 java-dependent packages with Jikes, so some dependencies on the JDK
246 can be replaced with a dependency on the JRE.</p>
247
248 <p>With some versions of Portage, doing an <c>emerge --update world</c>
249 will install the JDK regardless if whether you have it
250 installed before or not. This is a known bug addressed in later
251 versions of Portage.
252 </p>
253
254 </body>
255 </section>
256 </chapter>
257 </guide>

  ViewVC Help
Powered by ViewVC 1.1.20