classB cannot be cast to classC : java.lang.ClassCastException
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-5
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I have three classes:
When I run this code, I got this error:
java.lang.ClassCastException: classB cannot be cast to classC
What is the reason of this error and how to solve it?
public classB extends classA
}
}
public classC extends classB
}
}
public classX extends classD
}
}
...
Not working
public static void main(String args) throws Exception {
aa = new classX<Double>();
((ClassC<Double>) aa).set();
MM MMobj = ((ClassC<Double>) aa).get();
java oop
asked Nov 5 at 17:03
user10608907
42
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user10608907 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
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|
show 5 more comments
up vote
-5
down vote
favorite
I have three classes:
When I run this code, I got this error:
java.lang.ClassCastException: classB cannot be cast to classC
What is the reason of this error and how to solve it?
public classB extends classA
}
}
public classC extends classB
}
}
public classX extends classD
}
}
...
Not working
public static void main(String args) throws Exception {
aa = new classX<Double>();
((ClassC<Double>) aa).set();
MM MMobj = ((ClassC<Double>) aa).get();
java oop
asked Nov 5 at 17:03
user10608907
42
New contributor
user10608907 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
4
You simply can't cast an object to class it isn't an instance of. A direct instance ofRNis not an instance ofRNM, so you can't cast it to one.
– khelwood
Nov 5 at 17:05
@khelwood would you please give an example how it should be?
– user10608907
Nov 5 at 17:07
2
An example of what? I've got no idea what you are trying to do
– khelwood
Nov 5 at 17:08
@khelwood create subclass RNM which extends RN class, then run this((RNM<DoubleSol>) algo).setRF(new ArrayFr(rPF));in the main() method
– user10608907
Nov 5 at 17:13
All you've shown from yourmainis the cast, and no indication whatrPFis, wherealgocomes from, or why you're trying to cast it. Post a Minimal, Complete, and Verifiable example that shows what you're trying to do.
– khelwood
Nov 5 at 17:48
|
show 5 more comments
up vote
-5
down vote
favorite
up vote
-5
down vote
favorite
I have three classes:
When I run this code, I got this error:
java.lang.ClassCastException: classB cannot be cast to classC
What is the reason of this error and how to solve it?
public classB extends classA
}
}
public classC extends classB
}
}
public classX extends classD
}
}
...
Not working
public static void main(String args) throws Exception {
aa = new classX<Double>();
((ClassC<Double>) aa).set();
MM MMobj = ((ClassC<Double>) aa).get();
java oop
asked Nov 5 at 17:03
user10608907
42
New contributor
user10608907 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
I have three classes:
When I run this code, I got this error:
java.lang.ClassCastException: classB cannot be cast to classC
What is the reason of this error and how to solve it?
public classB extends classA
}
}
public classC extends classB
}
}
public classX extends classD
}
}
...
Not working
public static void main(String args) throws Exception {
aa = new classX<Double>();
((ClassC<Double>) aa).set();
MM MMobj = ((ClassC<Double>) aa).get();
java oop
java oop
asked Nov 5 at 17:03
user10608907
42
New contributor
user10608907 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
asked Nov 5 at 17:03
user10608907
42
New contributor
user10608907 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
edited Nov 7 at 13:05
asked Nov 5 at 17:03
user10608907
42
New contributor
user10608907 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
asked Nov 5 at 17:03
user10608907
42
asked Nov 5 at 17:03
user10608907
42
42
New contributor
user10608907 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
New contributor
user10608907 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
user10608907 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
4
You simply can't cast an object to class it isn't an instance of. A direct instance ofRNis not an instance ofRNM, so you can't cast it to one.
– khelwood
Nov 5 at 17:05
@khelwood would you please give an example how it should be?
– user10608907
Nov 5 at 17:07
2
An example of what? I've got no idea what you are trying to do
– khelwood
Nov 5 at 17:08
@khelwood create subclass RNM which extends RN class, then run this((RNM<DoubleSol>) algo).setRF(new ArrayFr(rPF));in the main() method
– user10608907
Nov 5 at 17:13
All you've shown from yourmainis the cast, and no indication whatrPFis, wherealgocomes from, or why you're trying to cast it. Post a Minimal, Complete, and Verifiable example that shows what you're trying to do.
– khelwood
Nov 5 at 17:48
|
show 5 more comments
4
You simply can't cast an object to class it isn't an instance of. A direct instance ofRNis not an instance ofRNM, so you can't cast it to one.
– khelwood
Nov 5 at 17:05
@khelwood would you please give an example how it should be?
– user10608907
Nov 5 at 17:07
2
An example of what? I've got no idea what you are trying to do
– khelwood
Nov 5 at 17:08
@khelwood create subclass RNM which extends RN class, then run this((RNM<DoubleSol>) algo).setRF(new ArrayFr(rPF));in the main() method
– user10608907
Nov 5 at 17:13
All you've shown from yourmainis the cast, and no indication whatrPFis, wherealgocomes from, or why you're trying to cast it. Post a Minimal, Complete, and Verifiable example that shows what you're trying to do.
– khelwood
Nov 5 at 17:48
4
4
You simply can't cast an object to class it isn't an instance of. A direct instance of
RN is not an instance of RNM, so you can't cast it to one.– khelwood
Nov 5 at 17:05
You simply can't cast an object to class it isn't an instance of. A direct instance of
RN is not an instance of RNM, so you can't cast it to one.– khelwood
Nov 5 at 17:05
@khelwood would you please give an example how it should be?
– user10608907
Nov 5 at 17:07
@khelwood would you please give an example how it should be?
– user10608907
Nov 5 at 17:07
2
2
An example of what? I've got no idea what you are trying to do
– khelwood
Nov 5 at 17:08
An example of what? I've got no idea what you are trying to do
– khelwood
Nov 5 at 17:08
@khelwood create subclass RNM which extends RN class, then run this
((RNM<DoubleSol>) algo).setRF(new ArrayFr(rPF)); in the main() method– user10608907
Nov 5 at 17:13
@khelwood create subclass RNM which extends RN class, then run this
((RNM<DoubleSol>) algo).setRF(new ArrayFr(rPF)); in the main() method– user10608907
Nov 5 at 17:13
All you've shown from your
main is the cast, and no indication what rPF is, where algo comes from, or why you're trying to cast it. Post a Minimal, Complete, and Verifiable example that shows what you're trying to do.– khelwood
Nov 5 at 17:48
All you've shown from your
main is the cast, and no indication what rPF is, where algo comes from, or why you're trying to cast it. Post a Minimal, Complete, and Verifiable example that shows what you're trying to do.– khelwood
Nov 5 at 17:48
|
show 5 more comments
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4
You simply can't cast an object to class it isn't an instance of. A direct instance of
RNis not an instance ofRNM, so you can't cast it to one.– khelwood
Nov 5 at 17:05
@khelwood would you please give an example how it should be?
– user10608907
Nov 5 at 17:07
2
An example of what? I've got no idea what you are trying to do
– khelwood
Nov 5 at 17:08
@khelwood create subclass RNM which extends RN class, then run this
((RNM<DoubleSol>) algo).setRF(new ArrayFr(rPF));in the main() method– user10608907
Nov 5 at 17:13
All you've shown from your
mainis the cast, and no indication whatrPFis, wherealgocomes from, or why you're trying to cast it. Post a Minimal, Complete, and Verifiable example that shows what you're trying to do.– khelwood
Nov 5 at 17:48