protected修饰符仅用于包中以及包外部的子类中。使用对象创建对象时Example ex=new Example();，默认情况下将调用父类的构造函数。
由于父类构造函数受到保护，因此您会遇到编译时错误。您需要根据JSL 6.6.2.2调用受保护的构造函数，如示例2所示。
package Super;
public class SuperConstructorCall {
protected SuperConstructorCall() {
}
}
package Child;
import Super.SuperConstructorCall;
public class ChildCall extends SuperConstructorCall
{
public static void main(String[] args) {
SuperConstructorCall s = new SuperConstructorCall(); // Compile time error saying SuperConstructorCall() has protected access in SuperConstructorCall
}
}
符合JLS 6.6.2.2的示例2 ：
package Super;
public class SuperConstructorCall {
protected SuperConstructorCall() {
}
}
package Child;
import Super.SuperConstructorCall;
public class ChildCall extends SuperConstructorCall
{
public static void main(String[] args) {
SuperConstructorCall s = new SuperConstructorCall(){}; // This will work as the access is by an anonymous class instance creation expression
}
}
602392714
清零编程群