Introducing Spring Framework

Chapter 5 ■ Working with Collections and Custom Types
Listing 5-6 Merge Example
In Listing 5-6, you can get anotherTypeDAO and it will contain the six types. But how does the Spring Framework
know about the merging? This is because your typeDAO bean has defined the attribute abstract with a value of true.
This means that it cannot be instantiated; it will be seen as a template by the container. All of the children beans
that make a reference of this parent bean will inherit all of the properties, such as the case of anotherTypeDAO that
inherited all the types properties, in this case the join/merge of the map. Also, you need to see that anotherTypeDAO
uses the attribute parent, making the reference to the parent bean the typeDAO.
If you think that Spring has another way to express collections in the XML based configuration, you are right. The
Spring Framework also supports, based on a namespace, a “shortcut” for declaring collections. Now you have more
options for using collections. See Listing 5-7 for an XML configuration example.
Listing 5-7. mydocuments-util-context.xml
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