java内部类

如下面代码：

 

public class OuterInnerTest
{
	public static void main(String[] args)
	{
		//1
		Outer outer = new Outer();
		outer.show();
		
		//2
		Outer.Inner inner = outer.getInner();
		inner.show();
		
		//3
		Outer.Inner inner2 = outer.new Inner();
		inner2.show();
	}
}

class Outer
{
	private int i = 3;
	
	class Inner
	{
		private int i = 6;
		
		public void show()
		{
			int i = 9;
			
			System.out.println(i);
			System.out.println(this.i);
			System.out.println(Outer.this.i);
		}
	}
	
	public void show()
	{
		Inner inner = new Inner();
		inner.show();
	}
	
	public Inner getInner()
	{
		return new Inner();
	}
}

 

 

输出为：

9
6
3

 

 

如下：

public class OuterInnerTest2 
{
	private int i = 3;
	
	public static void main(String[] args)
	{
		OuterInnerTest2 oit = new OuterInnerTest2();
		oit.show(12);
	}
	
	public void show(final int n)
	{
		class Inner
		{
			private int i = 6;
			
			public void show()
			{
				int i = 9;
				
				System.out.println(i);
				System.out.println(this.i);
				System.out.println(OuterInnerTest2.this.i);
				System.out.println(n);//n必须为final类型的
			}
		}
		
		Inner inner = new Inner();
		inner.show();
	}
}

 

输出为：

9
6
3
12