Tom*_*zyk 3 java default interface
我正在学习接口。这里会发生什么?以及为什么我收到一条消息:
“对超级类型SomeInterface2的非法引用,不能绕过更具体的直接超级类型interfejsy.SomeInterface3”
public interface SomeInterface1 {
public default void action(){
System.out.println("default interface1 method");
};
}
public interface SomeInterface2 {
public default void action(){
System.out.println("default interface2 method");
};
}
public interface SomeInterface3 extends SomeInterface2{
public default void action(){
System.out.println("default interface3 method");
}
}
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...
public class ClassImplementingInterface implements SomeInterface1, SomeInterface2, SomeInterface3{
//Every interface has action() method so we have to override it
@Override
public void action() {
SomeInterface1.super.action();
SomeInterface2.super.action(); //---- compiler error
SomeInterface3.super.action();
}
}
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您不能访问SomeInterface2的默认方法,因为它是SomeInterface3的超级接口。作为实现类,ClassImplementingInterface只能访问其直接超级接口的默认方法。从逻辑的角度来看,ClassImplementingInterface既实现了SomeInterface2又实现了SomeInterface3,但是SomeInterface2是超级接口,似乎不合理,如果必须这样做,请尝试以下程序。
public interface SomeInterface1 {
public default void action(){
System.out.println("default interface1 method");
};
}
public interface SomeInterface2 {
public default void action(){
System.out.println("default interface2 method");
};
}
public interface SomeInterface3 extends SomeInterface2{
public default void action(){
System.out.println("default interface3 method");
}
public default void action2(){
SomeInterface2.super.action();
}
}
public class ClassImplementingInterface implements SomeInterface1,SomeInterface2,SomeInterface3{
public void action() {
SomeInterface1.super.action();
SomeInterface3.super.action2();
SomeInterface3.super.action();
}
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}