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Figure 17.2.
The interaction of classes needed to open a file of any type. |
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Figure 17.3.
The interaction of classes needed to close a file of any type. |
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The File Operations Subsystem Class Hierarchy Model |
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In designing and implementing your own classes for this subsystem, it is important to remember that the classes in it will overlap with the Database Access Subsystem. Both the File Operations Subsystem and the Database Access Subsystem are forms of information persistence mechanisms, and in fact popular databases are nothing more than sophisticated file operation systems. |
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Figure 17.4 shows the hierarchy of classes related to each file. |
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