[ Pobierz całość w formacie PDF ]
you can download. Select the file format, provide an email address, hit next, and then fill out their lengthy
form. Be sure to supply a valid email address on the first page as you will be emailed a URL from which you
can download the software.
215
Installation
Warning ObjectSpace's Web site has a serious security problem. That is, you can enter anyone's email
address if that person has already registered, a phone number and address will appear prefilled
within the form. So, when filling out the form, don't enter any information you don't mind giving out
publicly aside from your own valid email address. Without it, you will not get the download URL.
After receiving the email, follow the link to download the software. Depending on which format you choose,
the size will vary. Expect about a 2 MB download, although the gzip version is less than 1 MB.
Installation
How you install the software depends upon which file type you download. Basically, you need to unpack it. If
you download either the Generic Zip, the Unix Tarred & Compressed, or the Unix Tarred & GZipped, you'll
need the appropriate tools to unpack it. For instance, for the Generic Zip format, you can use the jar utility that
comes with the JDK. This will unpack the files into a directory named jgl3.1.0:
jar xvf jgl3_1_0.zip
The self-extracting version is meant for the Windows platforms only. If you don't mind the extra bandwidth
required to download (it's the largest of the bunch), you can go through a common set of InstallShield prompts
to install the JGL Libraries as shown in Figures 17-1 through 17-5.
Figure 17-1: The JGL Libraries installation startup screen.
216
Installation
Figure 17-2: The JGL Libraries license agreement screen.
Figure 17-3: The JGL Libraries information screen.
Figure 17-4: The JGL Libraries installation destination screen.
217
Installation
Figure 17-5: The JGL Libraries component selection screen.
Just select "Next" or "Yes" on each screen. If you don't want to install onto the default device or directory
(usually C:\jgl3.1.0), you'll need to choose a different location on the fourth screen (see Figure 17-5). After
selecting "Next" on the fifth screen, the installation occurs.
Note Given the complexity of the libraries, you'll probably want to select the
Documentation option shown in Figure 17-5. However, if disk space is tight, you
can read it online at http://support.objectspace.com/. You don't really need the
source files unless you like digging through code to better understand things.
Before the self-extractor completes, you'll be prompted to update your CLASSPATH. If you select "Yes,"
your CLASSPATH will be adjusted to contain the JGL Libraries (along with the main JGL directory, which is
superfluously added into your CLASSPATH). On Windows 95/98 platforms, the following is added to a line
at the end of your AUTOEXEC.BAT file:
%CLASSPATH%;.;c:\jgl3.1.0;c:\jgl3.1.0\lib\jgl3.1.0.jar
On Windows NT/2000 platforms, the setting will be added or appended to your existing CLASSPATH in the
user's System Environment.
Warning Not everyone prefers to have the current directory (.) in their CLASSPATH. If you didn't have it
there before, it will be added whether you like it or not. Also, the automated setting of CLASSPATH
does not always preserve the current CLASSPATH, sometimes not prepending %CLASSPATH% in
the AUTOEXEC.BAT file.
The safest precaution is to manually set the CLASSPATH. If you select "No" during the running of the
self-extractor, or you manually unpacked one of the other installation formats, you must manually place the
JGL Libraries into your CLASSPATH. When programming with the Java 2 platform, it is easiest to place the
jgl3.1.0.jar file (found in the lib directory) into an appropriate directory for the Java Extensions Framework, in
order to load the .jar file without mucking with the CLASSPATH environment variable. You will need to
place the .jar file in the /jre/lib/ext directory of your Java Runtime Environment (JRE) so that the standard
Java extension mechanism can find the file. In the case of a Win32 user with the JDK 1.3 installed in
[ Pobierz całość w formacie PDF ]