内部类

package com.seki.base;

public class TESTCLS {

	public void test(){
		T1 t1 = new T1();
		System.out.println(t1.a);
		
		T2 t2 = new T2();
		System.out.println(t2.a);
		
		T3 t3 = new T3();
		System.out.println(t3.a);
		
		T4 t4 = new T4();
		System.out.println(t4.a);
		
	}
	
	public static void main(String[] args) {
		new TESTCLS().test();

		TESTCLS cls = new TESTCLS();
		T1 t1 = cls.new T1();
		System.out.println(t1.a);
		
		T3 t3 = new T3();
		System.out.println(t3.a);
	}
	
	private class T1{
		int a = 1;
	}
	
	public class T2{
		int a = 2;
	}
	
	private static class T3{
		int a = 3;
	}
	
	public static class T4{
		int a = 4;
	}
}

package com.seki.base;

import com.seki.base.TESTCLS.T2;
import com.seki.base.TESTCLS.T4;


public class RR {

	public static void main(String[] args) {
		TESTCLS cls = new TESTCLS();
		T2 t=cls.new T2();
		
		T4 t4 = new T4();
	}

}