Im using the following code that the fieldValue can have simple property , there is a way to check before im doing this code if fieldValue is not contain object that cannot be cast to string ?to avoid dump
keyVal.put(fieldName, (String) fieldValue);
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Is there any class in Java that cannot be casted to String? – Jakub Matczak Jun 10 '13 at 18:11
3 Answers
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if (fieldValue instanceof String)
SLaks
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I cannot use ti since field value is type object and can have there either numbers so the if will not success – James Berners Jun 10 '13 at 17:10
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@James Berners: By type object, are you talking about `Class` type? If so, then you can use `asSubclass()` function to convert it into String class or use `isAssignableFrom()` to check if its a super-class of String. – keelar Jun 10 '13 at 17:17
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@fge I have tried it I for example I got type object and there is value like 10 and the if is not work – James Berners Jun 10 '13 at 17:21
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If by "not work" you mean evaluate to `false` then that is to be expected, since `Integer` cannot be cast to `String`. – arshajii Jun 10 '13 at 17:23
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@JamesBerners: if what you need is a string representation of an Object, then my answer might be a fit for you. – keelar Jun 10 '13 at 17:56
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Since String is a final class (and hence cannot have subclasses), I would consider using getClass over instanceof:
if (fieldValue != null && fieldValue.getClass() == String.class)
arshajii
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if (fieldValue instanceof String) {
keyVal.put(fieldName, (String) fieldValue);
}
Juned Ahsan
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I cannot use it since the if will not work ,the data fieldValue is type object... – James Berners Jun 10 '13 at 17:17