Java Reference
In-Depth Information
you to the basic concepts required for a fundamental understanding. If you're
new to the idea of version control, we encourage you to explore it further: It's a
critical component of any professional software development project.
Version control systems are designed to manage your project's source code to
provide an accurate accounting of all the changes made to it. Using this informa-
tion, the version control system lets you revisit older revisions of your code and
analyze the differences between them. Doing so ensures that you can reverse any
changes that turn out to be bad ideas and retrieve any code you may lose to file
deletion. Most systems also allow you to maintain multiple concurrent versions of
a project that diverge at a common version in the past. This is known as
branching
the code. You might do this to create a new version of the software with additional
features that you don't want to be included in the main distribution. A summary
of some of the version control terminology you'll encounter is shown in table 8.1.
Table 8.1
A brief glossary of version control terminology
Term
Meaning
Repository
The centralized location where all the master copies of your project's files are kept,
along with their revision histories.
Working directory
The developer's local copy of the source code stored in the repository.
Check out
How you obtain a local copy of your project's files from the repository in order to
make your changes. Each member of the project checks out their own copy of the
project into their own working directory.
Check in
The process of sending any modified project files back to the repository. Checking in
your changes is also known as
committing
your files.
Revision
A snapshot of your file that is created each time you check in your changes. This lets
you return to older versions of the file if necessary.
Update
How you synchronize your copy of the project files with the most recent versions in
the repository, ensuring that you pick up any changes checked in by other members
of the team.
Roll back
To Revert a file back to an earlier revision of itself.
All of your source code is stored in a central location called a
repository
. This is
usually located on a central server, and it holds not only the source code itself but
a database of all the changes made to it, including who made them and when.
The source code repository is usually backed up on a regular basis.
When developers want to work on a source file, they must first check it out
from the repository. The developers' local copy is known as their
working directory
.
