静态工厂方法的实际用例?

javax.swing.BorderFactory

the javadoc

• createEmptyBorder() createEtchedBorder()
• Border

Integer.valueOf(int) Boolean Short Long Byte Integer

new Integer() new

Guava ImmutableList

• ImmutableList public protected
• ImmutableList.of() EmptyImmutableList
• ImmutableList.of(E) SingletonImmutableList
• RegularImmutableList
• copyOf(Collection) Collection

Calendar.getInstance()

Card:
  suit
  rank

Deck:
  card[]

Printer

   public interface Printer {
       print();
    }

    class CanonPrinter implements Printer {
       print() {
    // ...
       }
    }


    public PrinterFactory {

    Printer createPrinter() {
   if (... ) {
      return new CanonPrinter();
   } else {
      return new EpsonPrinter();
   }
}
}

Printer printer = PrinterFactory.createPrinter();
printer.print();