Joshua Bloch撰写的有效Java：条款1-静态工厂方法

Foo

MyFoo

Foos

 public interface Foo{ //interface without plural \'s\' (question 1)
     public void bar();
 }
 public abstract class Foos(){ // abstract factory with plural \'s\' (question 1)
    public static Foo createFoo(){
        return new MyFoo();
    }
    private class MyFoo implements Foo{ // a non visible implementation (question 2)
       public void bar(){}
    }
 }

List

List

public class ListFactory{
  private ListFactory(){}
  public static List makeArrayList(){...}
  public static List makeLinkedList(){...}
  public static List makeCrazyList(){...}
}

public interface List{
   public static List makeArrayList();
   public static List makeLinkedList();
   public static List makeCrazyList();
}

public interface Foo
    static public class Factory
        public Foo create(){..}

Foo foo = Foo.Factory.create();

Collection

Collections

emptyList

Collection.emptyList

List

List

java.util.Collections.UnmodifiableList