Spring Packaging for
, shown in Figure 6.1, are
conceptual groups of functionality provided by the
of Spring's Java packages and underlying classes.
Figure 6.2 shows the various top-level Spring
packages. (Note:The shaded packages are ones we will use for our
sample application, again demonstrating that Spring does not take
an all-or-nothing approach.)
Figure 6.2. Spring's top-level Java
packages under org.springframework.
Overwhelmed by the Size of the Spring
The Spring Framework contains something along
the lines of 130+ Java packages and 1,200+ Java classes. However,
do not be overwhelmed by this number; here is why.
First, you may want to use only Spring's IoC
features, so you could essentially ignore most of the APIs. Second,
although there are lots of classes and there's lots of Javadoc,
many of these classes are for internal use by the framework itself.
Third, Spring enables you to select the modules you want to use and
ignore the rest. For example, we will use only a handful of these
for our sample application, Time Expressionthis is proof that
Spring's design is highly modular.