enclosing.java

国外的数据结构与算法分析用书

/**	The enclosing class. */
public class Enclosing
{
	/**	Instance variable known to Enclosing and Inner. */
	private int a;

	/**	A reference to an instance of Inner. */
	private Inner anInner;

	/**	Constructor for Enclosing. */
	public Enclosing(int a)
	{
		this.a = a;
		anInner = new Inner(a * 2);
	}

	/**	A function that uses the members of the inner class. */
	public int foo()
	{
		return anInner.fooInner() + anInner.b;
	}
	
	/**	The inner class. */
	public class Inner
	{
		/**	Instance variable of Inner. */
		private int b;

		public Inner(int b)
		{
			this.b = b;
		}

		/**	Method using the instance variables of Enclosing and Inner. */
		public int fooInner()
		{
			return a + b;
		}
	}

	/**	Starting point of the program. */
	public static void main(String[] args)
	{
		Enclosing test = new Enclosing(5);
		System.out.println(test.foo());
	}
}