浅谈java面向对象中四种权限

package Main;
public class Private {
	private int a;
	private int b;
	Protected (){
		this.a=1;
		this.b=2;
		//a和b只能在Private类中调用
	}
	private void set(){
		System.out.println(""+a+""+b+"\n");
	}
	void Print(){
		this.set();
		//只能在这里用；
	}
}

package Main;
import Protected.*;
public class Main {
	public static void main(String args[]){
		Protected jkl=new Protected();
		jkl.Print();
		//调用jkl父类的protect方法 
		Frindly prot =new Frindly();
		System.out.println(prot.a);
		//在Main类中调用友好型的变量 
		prot.set();
		//在Main类中调用友好型的方法
	}
}
package Main;
public class Frindly {
	int a,b,c,d;
	Frindly(){
		a=b=c=d=1;
	}
	void set (){
		System.out.print(""+a+" "+b+"\n");
	}
}
package Main;
public class Protectedfather{
	protected int a;
	private int b;
	protected Protectedfather (){
		this.a=1;
		this.b=2;
		//a和b只能在Protected中调用
	}
	private void set(){
		System.out.println(""+a+""+b+"\n");
	}
	protected void Print(){
		this.set();
		//只能在这里用；
	}
}
package Protected;
import Main.*;
public class Protected extends Protectedfather{
	public Protected(){
		super();
		//在另一个包中调用里父类中的protect构造方法 
		super.a=12;
		//调用父类的protect变量
	}
}

package Main;
import Public.*;
public class Main {
	public static void main(String args[]){
		int a;
		Public p=new Public();
		//调用public类中的public方法 
		a=p.a;
		//调用Public类中的public变量 
		p.set();
	}
}
package Public;
public class Public {
	public int a=12;
	public void set (){
		System.out.println("OK\n");
	}
}