Design Patterns Java™ Workbook

Beyond Ordinary Construction

Java's constructor features provide many alternatives when you design a new class. However, constructors are effective only if the user of your class knows which class to instantiate and knows the required fields for instantiating an object. For example, the choice of which user interface component to compose may depend on whether the program is running on a handheld device or on a larger display. It can also happen that a developer knows which class to instantiate but does not have all the necessary initial values or has them in the wrong format. For example, the developer may need to create an object from a dormant or a textual version of an object. In such circumstances, you need to go beyond the use of ordinary ...