doc/en/java.xml

<?xml version='1.0' encoding="UTF-8"?>
<!DOCTYPE guide SYSTEM "/dtd/guide.dtd">

<guide link = "/doc/en/java.xml">
        <title>Gentoo Java Guide</title>
        <author title="Author and Editor">
        <mail link="karltk@gentoo.org">Karl Trygve Kalleberg</mail>
        </author>

        <abstract>
        Users' and Developers' Guide to Java in Gentoo
        </abstract>

    <license/>

        <version>0.1.2</version>
        <date>September 4, 2002</date>

                <chapter>
                <title>Installing a JDK/JRE</title>
                        <section>
                                <title>Overview</title>
                                <body>
                                
                        <p>Gentoo provides numerous JDKs and JREs. The default is the
                        Blackdown JDK/JRE pair, as it is freely (beer) available without any
                        registration fuss.
                        </p>

                        <note>As kaffe becomes a JRE/JDK drop-in replacement, that will most
                        likely become our default.
                        </note>

                        <p>Both the Sun JDK/JRE and the IBM JDK/JRE are generally faster, but
                        getting them is a bit more work, as you are required to read and
                        accept their license before downloading (IBM additionally requires you
                        to register).
                        </p>

                        <p>Our ebuilds for the Sun and IBM JDK/JREs will notify you of where
                        to go to download them.
                        </p>
                        
                        </body>
                </section>

                <section>
                        <title>Installing the Sun/IBM JDK/JREs</title>
                        <body>

                        <p>If you run <c>emerge sun-jdk-1.3.1</c> or <c>emerge
                        ibm-jdk-1.3.1</c>, you will be notified that you are required
                        to download the actual tarballs yourself. This has to do with license
                        restrictions for the Sun JDK/JRE (online click-wrap license) and
                        registration issues with the IBM JDK/JRE.
                        </p>

                        <note>There is also a sun-jdk-1.4.0, but not all packages
                        work nicely with Java 1.4, so you're on your own if you use the 1.4.0
                        JDK.
                        </note>

                        <p>You should download the indicated file(s) into
                        <path>/usr/portage/distfiles</path>. Once that is done, you can rerun
                        the emerge command, then the JDK/JRE will be installed properly into
                        <path>/opt</path>.
                        </p>
                        
                        </body>
                </section>
        </chapter>

        <chapter>
                <title>Configuring your JDK/JRE</title>
                
                <section>
                        <title>Overview</title>
                        
                        <body>
                        
                        <p>Gentoo has the ability to have multiple JDKs and JREs installed
                        without them conflicting. There are a few caveats to this, as noted
                        below.
                        </p>

                        <p>Using the <c>java-config</c> tool, you can set the system-wide
                        default if you have root access. Users can also use <c>java-config</c>
                        to set up their own personal default, that is different from the
                        system-wide default.
                        </p>
                        
                        </body>
                </section>

                <section>
                        <title>Setting a default JDK/JRE</title>
                        <body>

                        <p>Running the command <c>java-config --list-available-vms</c> will
                        give you a list of all availble JREs and JDKs on your system, thus:</p>
                        
                        <pre caption = "Listing available VMs">
[%1 ~] java-config --list-available-vms
[blackdown-jdk-1.3.1] Blackdown JDK 1.3.1 (/etc/env.d/java/20blackdown-jdk-1.3.1)
[blackdown-jre-1.3.1] Blackdown JRE 1.3.1 (/etc/env.d/java/20blackdown-jre-1.3.1)
[ibm-jdk-1.3.0] IBM JDK 1.3.0 (/etc/env.d/java/20ibm-jdk-1.3.0)
[ibm-jdk-1.3.1] IBM JDK 1.3.1 (/etc/env.d/java/20ibm-jdk-1.3.1)
[ibm-jre-1.3.1] IBM JRE 1.3.1 (/etc/env.d/java/20ibm-jre-1.3.1)
[sun-jdk-1.4.0] Sun JDK 1.4.0 (/etc/env.d/java/20sun-jdk-1.4.0)
                        </pre>
                        
                        <p>The name in the brackets <path>"[]"</path> is the handle or ID for
                        that particular VM. You use pass that ID to <c>java-config
                        --set-system-vm</c>, thus:
                        </p>

                        <pre caption = "Setting the System VM">
[#1 ~] java-config --set-system-vm=ibm-jdk-1.3.1
Now using IBM JDK 1.3.1 (/etc/env.d/java/20ibm-jdk-1.3.1)
                        </pre>

                        <note>You will have to be root to run --set-system-vm
                        </note>

                        <p>Once you have issued <c>java-config --set-system-vm</c> with a
                        particular VM ID, you will need to regenerate your /etc/profile.env,
                        thus:
                        </p>
                        
                        <pre caption = "Regenerating /etc/profile.env" >
[#1 ~] env-update
                        </pre>

                        <p>After this, you will either want to relogin, or resource
                        <path>/etc/profile</path> into your environment.
                        </p>

                        <p>As a regular user, you can use <c>java-config --set-user-vm</c>,
                        which will create <path>$HOME/.gentoo/java-env</path> with all
                        required env vars. You would normally source this from your shell's
                        startup script (<path>$HOME/.zshenv</path> in my case).</p>
                        
                        </body>
                </section>

                <section>
                        <title>Setting a default CLASSPATH</title>
                        <body>

                        <p><c>java-config</c> can also be used to set a system-wide default
                        CLASSPATH, and of course a user-specific default CLASSPATH.
                        </p>

                        <p>First you want to list available java libraries that might be
                        interesting to put in your CLASSPATH, thus:
                        </p>
                        
                        <pre caption = "Listing classes">
[%1 ~] java-config --list-available-packages
[ant] No description (/usr/share/ant/classpath.env)
[java-gnome] No description (/usr/share/java-gnome/classpath.env)
[java-gtk] No description (/usr/share/java-gtk/classpath.env)
[log4j] "" (/usr/share/log4j/package.env)
                        </pre>

                        <note>None of these packages have a proper description. That is
                        something that will be implemented in the not-so-distant
                        future.
                        </note>

                        <p>Again, the name in brackets <path>"[]"</path> are the IDs that you
                        have to pass to <c>java-config --set-system-classpath</c>, thus:
                        </p>

                        <pre caption = "Setting classpaths">
java-config --set-system-classpath=log4j,java-gtk,java-gnome
                        </pre>
                        
                        <note>The current directory (.) will not be part of the system classpath,
                        as that should be added in root's login profile.
                        </note>

                        <p>Again, you will want to run <c>env-update</c> to update your
                        system's environment, and you might also want to relogin or resource
                        the <path>/etc/profile</path>.
                        </p>
                        
                        <p>For users, <c>java-config --set-user-classpath</c> will create
                        <path>$HOME/.gentoo/java-env-classpath</path>, which is automatically
                        included by <path>$HOME/.gentoo/java-env</path>.
                        </p>
                        
                        </body>
                </section>
        </chapter>

        <chapter>
                <title>Additional resources</title>
                <section>
                        <title>Off-line resources</title>
                        
                        <body>

                        <ul>
                                <li>java-config man page</li>
                                <li><c>java-config --help</c></li>
                                <li>The <path>/usr/bin/java-config</path> script itself</li>
                        </ul>
                        
                        </body>
                </section>

                <section>
                        <title>Online resources</title>

                        <body>

                        <ul>
                        <li>The <uri link="http://news.gmane.org/gmane.linux.gentoo.devel">
                                gentoo-dev </uri>, 
                                <uri link="http://news.gmane.org/gmane.linux.gentoo.user"> gentoo-user
                                </uri> mailing list archives</li>
                        <li>#gentoo on irc.openprojects.net</li>
                        </ul>
                        
                        </body>
                </section>
        </chapter>

        <chapter>
                <title>Caveats</title>
                <section>
                        <title>General</title>

                        <body>
                        
                        <p>If you select a JRE as your default VM, you may not have a
                        <c>javac</c> command handy at all times, unless you have manually
                        installed a symlink to take care of that.
                        </p>

                        <p>Jikes will be used to compile some of the largest packages, if it
                        is available. With time, we hope to be able to compile all
                        java-dependent packages with Jikes, so some dependencies on the JDK
                        can be replaced with a dependency on the JRE.</p>

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