chap4-13.txt

JAVA 学习资源

// 程序4-13
class point{  
    int x, y;

    point(int a, int b){
        x=a;  
        y=b;
        System.out.println("point constructor:"+getString( ));
    }

    public void finalize( ){             // 增加的方法
        System.out.println("point finalizer:"+getString( ));
    }
    String getString( ){      return "x="+x+"  y="+y;    }
}

class circle extends point{
    int radius;

    circle(int r, int a, int b){
        super(a,b);    
        radius=r;
        System.out.println("circle constructor:"+getString( ));
    }

    public void finalize( ){ 			// 增加的方法
        System.out.println("circle finalizer:"+getString( ));
   }

    String getString( ){    return  super.getString( )+"   radius="+radius;    }
}

public class testFinalize {
    public static void main(String args[ ]) {
        point c1,c2;

        c1=new circle(1,1,1);    
        c2=new circle(2,2,2);    

        c1=null; 		// c1,c2现在可以被垃圾收集器回收
        c2=null;
        System.gc( );    	// 调用垃圾收集器
    }
}