Avoiding an unchecked cast for deepcopying map
0
I'm trying to implement a deepCopy method for a multi valued map like this:
public static <K, V> ListValuedMap<K, V> deepCopy (ListValuedMap<K, V> a) {
ListValuedMap<K, V> result = new ArrayListValuedHashMap<>();
a.asMap().forEach((key, value) -> {
Object newValue;
if (value instanceof ListValuedMap) {
newValue = deepCopy((ListValuedMap<K, V>) value);
‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾
unchecked cast!
} else if (value instanceof Cloneable) {
try {
Method clone = value.getClass().getDeclaredMethod("clone");
newValue = clone.invoke(value);
} catch (NoSuchMethodException | IllegalAccessException | InvocationTargetException e) {
throw new RuntimeException(e);
}
} else {
newValue = value;
}
result.put(key, (V) newValue);
‾‾‾
unchecked cast !
});
return result;
}
The second Unchecked cast can be avoided by passing the class for the V value type paramater argument and using vClass.cast(newValue), but I have no idea on how to procede for the first error.
java unchecked
asked Nov 16 '18 at 10:17
Vinz243Vinz243
4,18453169
|
show 1 more comment
0
I'm trying to implement a deepCopy method for a multi valued map like this:
public static <K, V> ListValuedMap<K, V> deepCopy (ListValuedMap<K, V> a) {
ListValuedMap<K, V> result = new ArrayListValuedHashMap<>();
a.asMap().forEach((key, value) -> {
Object newValue;
if (value instanceof ListValuedMap) {
newValue = deepCopy((ListValuedMap<K, V>) value);
‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾
unchecked cast!
} else if (value instanceof Cloneable) {
try {
Method clone = value.getClass().getDeclaredMethod("clone");
newValue = clone.invoke(value);
} catch (NoSuchMethodException | IllegalAccessException | InvocationTargetException e) {
throw new RuntimeException(e);
}
} else {
newValue = value;
}
result.put(key, (V) newValue);
‾‾‾
unchecked cast !
});
return result;
}
The second Unchecked cast can be avoided by passing the class for the V value type paramater argument and using vClass.cast(newValue), but I have no idea on how to procede for the first error.
java unchecked
asked Nov 16 '18 at 10:17
Vinz243Vinz243
4,18453169
The first can be avoided by using<?,?>. The second cannot be avoided. Suppress it.
– Michael
Nov 16 '18 at 10:39
@Michael it's the other way around, the second maybe avoided using a class.cast the first one I cant see how
– Vinz243
Nov 16 '18 at 10:43
If you think the second can be avoided, why did you ask the question about it? It can't by the way.
– Michael
Nov 16 '18 at 10:45
result.put(key, vClass.cast(newValue)); doens't throw anything
– Vinz243
Nov 16 '18 at 10:46
You can't get V's class.
– Michael
Nov 16 '18 at 10:47
|
show 1 more comment
0
0
0
I'm trying to implement a deepCopy method for a multi valued map like this:
public static <K, V> ListValuedMap<K, V> deepCopy (ListValuedMap<K, V> a) {
ListValuedMap<K, V> result = new ArrayListValuedHashMap<>();
a.asMap().forEach((key, value) -> {
Object newValue;
if (value instanceof ListValuedMap) {
newValue = deepCopy((ListValuedMap<K, V>) value);
‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾
unchecked cast!
} else if (value instanceof Cloneable) {
try {
Method clone = value.getClass().getDeclaredMethod("clone");
newValue = clone.invoke(value);
} catch (NoSuchMethodException | IllegalAccessException | InvocationTargetException e) {
throw new RuntimeException(e);
}
} else {
newValue = value;
}
result.put(key, (V) newValue);
‾‾‾
unchecked cast !
});
return result;
}
The second Unchecked cast can be avoided by passing the class for the V value type paramater argument and using vClass.cast(newValue), but I have no idea on how to procede for the first error.
java unchecked
asked Nov 16 '18 at 10:17
Vinz243Vinz243
4,18453169
I'm trying to implement a deepCopy method for a multi valued map like this:
public static <K, V> ListValuedMap<K, V> deepCopy (ListValuedMap<K, V> a) {
ListValuedMap<K, V> result = new ArrayListValuedHashMap<>();
a.asMap().forEach((key, value) -> {
Object newValue;
if (value instanceof ListValuedMap) {
newValue = deepCopy((ListValuedMap<K, V>) value);
‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾
unchecked cast!
} else if (value instanceof Cloneable) {
try {
Method clone = value.getClass().getDeclaredMethod("clone");
newValue = clone.invoke(value);
} catch (NoSuchMethodException | IllegalAccessException | InvocationTargetException e) {
throw new RuntimeException(e);
}
} else {
newValue = value;
}
result.put(key, (V) newValue);
‾‾‾
unchecked cast !
});
return result;
}
The second Unchecked cast can be avoided by passing the class for the V value type paramater argument and using vClass.cast(newValue), but I have no idea on how to procede for the first error.
java unchecked
java unchecked
asked Nov 16 '18 at 10:17
Vinz243Vinz243
4,18453169
asked Nov 16 '18 at 10:17
Vinz243Vinz243
4,18453169
asked Nov 16 '18 at 10:17
Vinz243Vinz243
4,18453169
asked Nov 16 '18 at 10:17
Vinz243Vinz243
4,18453169
asked Nov 16 '18 at 10:17
Vinz243Vinz243
4,18453169
4,18453169
The first can be avoided by using<?,?>. The second cannot be avoided. Suppress it.
– Michael
Nov 16 '18 at 10:39
@Michael it's the other way around, the second maybe avoided using a class.cast the first one I cant see how
– Vinz243
Nov 16 '18 at 10:43
If you think the second can be avoided, why did you ask the question about it? It can't by the way.
– Michael
Nov 16 '18 at 10:45
result.put(key, vClass.cast(newValue)); doens't throw anything
– Vinz243
Nov 16 '18 at 10:46
You can't get V's class.
– Michael
Nov 16 '18 at 10:47
|
show 1 more comment
The first can be avoided by using<?,?>. The second cannot be avoided. Suppress it.
– Michael
Nov 16 '18 at 10:39
@Michael it's the other way around, the second maybe avoided using a class.cast the first one I cant see how
– Vinz243
Nov 16 '18 at 10:43
If you think the second can be avoided, why did you ask the question about it? It can't by the way.
– Michael
Nov 16 '18 at 10:45
result.put(key, vClass.cast(newValue)); doens't throw anything
– Vinz243
Nov 16 '18 at 10:46
You can't get V's class.
– Michael
Nov 16 '18 at 10:47
The first can be avoided by using
<?,?>. The second cannot be avoided. Suppress it.– Michael
Nov 16 '18 at 10:39
The first can be avoided by using
<?,?>. The second cannot be avoided. Suppress it.– Michael
Nov 16 '18 at 10:39
@Michael it's the other way around, the second maybe avoided using a class.cast the first one I cant see how
– Vinz243
Nov 16 '18 at 10:43
@Michael it's the other way around, the second maybe avoided using a class.cast the first one I cant see how
– Vinz243
Nov 16 '18 at 10:43
If you think the second can be avoided, why did you ask the question about it? It can't by the way.
– Michael
Nov 16 '18 at 10:45
If you think the second can be avoided, why did you ask the question about it? It can't by the way.
– Michael
Nov 16 '18 at 10:45
result.put(key, vClass.cast(newValue)); doens't throw anything
– Vinz243
Nov 16 '18 at 10:46
result.put(key, vClass.cast(newValue)); doens't throw anything
– Vinz243
Nov 16 '18 at 10:46
You can't get V's class.
– Michael
Nov 16 '18 at 10:47
You can't get V's class.
– Michael
Nov 16 '18 at 10:47
|
show 1 more comment
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The first can be avoided by using
<?,?>. The second cannot be avoided. Suppress it.– Michael
Nov 16 '18 at 10:39
@Michael it's the other way around, the second maybe avoided using a class.cast the first one I cant see how
– Vinz243
Nov 16 '18 at 10:43
If you think the second can be avoided, why did you ask the question about it? It can't by the way.
– Michael
Nov 16 '18 at 10:45
result.put(key, vClass.cast(newValue)); doens't throw anything
– Vinz243
Nov 16 '18 at 10:46
You can't get V's class.
– Michael
Nov 16 '18 at 10:47