This week's book giveaway is in the OCAJP 8 forum. We're giving away four copies of OCA Java SE 8 Programmer I Study Guide and have Edward Finegan & Robert Liguori on-line! See this thread for details.
There is no such thing as a "32-bit JAR file". Java code is independent of the underlying platform. It doesn't matter whether you compile your Java source code on a 32-bit or on a 64-bit JDK - you'll get the same byte code out of it.
The 32-bit or 64-bit is only relevant when your program contains native code, not written in Java, but for example in C or C++.