第1个回答 2011-01-01
class CountClass{
static public int sum=0;
private CountClass(){
}
static public CountClass getCountClass(){
if(CountClass.sum>2) {
System.out.println("对象实例超过3!");
return null;
}
else {
CountClass.sum++;
return new CountClass();
}
}
static public void main(String[] str){
CountClass s1=CountClass.getCountClass();
System.out.println(CountClass.sum+" "+s1);
CountClass s2=CountClass.getCountClass();
System.out.println(CountClass.sum+" "+s2);
CountClass s3=CountClass.getCountClass();
System.out.println(CountClass.sum+" "+s3);
CountClass s4=CountClass.getCountClass();
System.out.println(CountClass.sum+" "+s4);
}
}