what does b in java -fullversion indicates?

Question

When we use java -fullversion, we get output like java full version "1.7.0_45-b18".

what is this b18 in java full version?

I went thorough some oracle java articles which says that it is indicates build versions. So what is this build version supposed to be?

Also I see that some bugs on http://bugs.java.com/ which says that they are backported from higher version. For example : http://bugs.java.com/bugdatabase/view_bug.do?bug_id=8018840

It says that "Affected Versions: 7u45" and "Fixed Versions: 7u45 (b01)".

So what is this Fixed Versions: 7u45 (b01) indicates? Does this mean it is fixed in some later build of same java version?

Also as my current java -fullversion command says : "1.7.0_45-b18". SO does it mean that there are 18 different build for 7u45?

Answer 1

b18 does not refer to having 18 builds in your system. The concept is like:- Once code completion is done by developers on few features of the software, the lines of code is converted to a software or application so that we can use it. Each Build is numbered and it keeps changing with every release of that new version. So b18 has all previous features and new features included i.e an updated version of the software and your OS will update the software(if automatic update is enabled) rather than keeping copy of each build. Hope this clarifies your doubt to some extent... :)

Answer 2

From the Javadoc source:

JRE Family Version  JRE Security Baseline
                    (Full Version String)
7                   1.7.0_45
6                   1.6.0_65
5.0                 1.5.0_55

So as you have already found b means the "build" and 1.7.0_45 is the JRE Security baseline which represents JRE Family Version 7. And b18 is the Build 18.