The JDK Package is located on 10.7.5.1 in the directory /opt/eq-ORIG/dist/distro.
It's filename is 1.2.1_03_jdk_sparc.tar.Z
Further information are in jdk-1.2.1_03.README
Installation is simplest if the JDK tar file is downloaded into an empty current working directory.
 

Extract the contents of the compressed tar file:

$ zcat 1.2.1_03_jdk_sparc.tar.Z | tar -xf -

This will create a set of six files and four packages:

README.sparc
LICENSE.ps
COPYRIGHT
1.2.1_03_Developer-Guide.ps
1.2.1_03_Release-Notes.ps
1.2.1_03_Release-Notes.html
SUNWj2rt
SUNWj2dev
SUNWj2man
SUNWj2dem

README.sparc is this README file; the LICENSE file is a copy of the license agreement.

Become root:

$ su

Run the pkgadd command to install the packages:

# pkgadd -d . SUNWj2rt SUNWj2dev SUNWj2man SUNWj2dem

This will install the JDK into /usr/java1.2; see the pkgadd(1) and admin(4) man pages for information on installing the JDK in an alternate location.

Change to directory /usr/bin:

# cd /usr/bin

Check if the link java exists:

# ls -l java

if it exists delete it:

# rm java

Create a new link:

# ln -s /usr/java1.2 java

Check if there is the right version of the JDK1.2:

# java -version

The ouput should looks like:

java version "1.2.1"
Solaris VM (build Solaris_JDK_1.2.1_03, native threads, sunwjit)

If there is shown another java version check step from beginning

Delete the tar files and extracted directories.

Now the JDK1.2 is installed.