Cast to a literal (ex. "java.math.BigDecimal")

Question

I have an array with 2 columns like:
"java.math.BigDecimal", "2"
"java.lang.String", "Test 01"
"java.math.BigDecimal","120"
"java.math.BigDecimal","148"
"java.lang.String", "Test 02"
Is there way to cast the second string to the correct object type, using the first string.
Something like this:
("java.math.BigDecimal")("2")
("java.lang.String")("Test 01")
thanks in advance,
intovoid

Answer 1

You could do this by reflection for classes which
have a contructor which takes an single string
parameter - which I believe all these classes do.
Lot's of messy expections to field. The sequence
would be something like:
private static Object create(String[] columns) throws
Exception {
Class clazz = Class.forName(columns[0]);  // get
the class
Contstructor cons = clazz.getConstructor(new
Class[]{String.class}); // get constructor from
String
return cons.newInstance(new Object[]{columns[1]});
// construct object
code]Except, the problem remains that the OP can still not cast the Object returned by newInstance() by using the String in columns[0] (even though the Object is a BigDecimal). Even if it could be cast "dynamically", what would it be cast into - you can not dynamically declare the variable type.
The above method could work if all the possible objects returned implemented a common interface. Or maybe instanceof could be used to hard-code the cast to the possible objects.
In the end, I think this type of code can lead to a brittle design.