java 包

//第一个

package bzu.info.software;

public class Circle{
prinvate double radius;
Cricle(double r){
radius=r;
}
public void setRadius(double r){
radius=r;
}
public double getRadius(){
return radius;
}
public double getArea(){
double t;
t=Math.PI*radius*radius;
return t;
}

}

//第二个

package bzu.info;
public class A{
public static void main (String args[]){
Complex c;
c=new Complex(4.0,3.0);
c.print();
}
}

注意

javac -d . Complex.java

javac -d . A.java

java bzu.info.A