Installation guide

3. SERVLETEXEC/NSAPI: NES/IWS/SUN ONE PLUGIN (WINDOWS)
Important
The JDK or JRE must be installed on a local drive and not on a mapped network drive. If the
JDK/JRE has been installed on a mapped network drive, ServletExec/NSAPI will not be able
to load and initialize the Java VM.
3.2.3.1 Multiple JDK/JRE Versions Installed
You may have multiple versions of the JDK/JRE installed on your system.
ServletExec/NSAPI (including the installer) uses registry entries to determine which
installed JDK/JRE to use. It will look for an installed JDK first and if it doesn’t find one
it will look for a JRE. It will look for JDK/JREs from vendors in the following order: Sun
Microsystems, and then IBM. Study the complete algorithm that follows.
How ServletExec selects an installed JDK/JRE
1. Look for a Sun JDK using the following registry key:
HKEY_LOCAL_MACHINE\SOFTWARE\JavaSoft\Java Development Kit
 If Sun JDK found, go to Step 2. Otherwise, look for a Sun JRE using the
following key:
HKEY_LOCAL_MACHINE\SOFTWARE\JavaSoft\Java Runtime Environment
 If Sun JRE found, go to Step 2. Otherwise, look for an IBM JDK or JRE using
the following keys .
HKEY_LOCAL_MACHINE\SOFTWARE\IBM\Java Development Kit
or…
HKEY_LOCAL_MACHINE\SOFTWARE\IBM\Java Runtime Environment
 If no Sun or IBM JDK/JRE found using the above registry keys, then abort
ServletExec installer.
2. Read the
CurrentVersion variable from the key found in Step 1. Currently, the
only valid values for this variable start with “1.3” or “1.4” (including, for example
“
1.4.2”).
3. Append the value of the CurrentVersion variable from Step 2 to the key from
Step 1 to create a new key. For example:
HKEY_LOCAL_MACHINE\SOFTWARE\JavaSoft\Java Development Kit\1.4
or…
HKEY_LOCAL_MACHINE\SOFTWARE\JavaSoft\Java Runtime Environment\1.4
4. Read the value of the JavaHome variable for the key from Step 3 to find the
location of the JDK or JRE.
If you launch the
DBMON debugging tool and then restart your web server,
ServletExec/NSAPI displays the Java VM settings in the
DBMON console window during
initialization. You can examine the classpath displayed by ServletExec/NSAPI in the
DBMON console window to see which version of the JDK is being used.
See Section 12.4 of the ServletExec 5.0 User Guide for a discussion of
DBMON.
ServletExec 5.0 Installation Guide 21