I have a set of classes that implement a certain interface. I have put all those classes in a Hashtable ht like this:
ht.put(str,backend.instructions.ADC.class); But when I call the get() function of the hashtable and try to cast the object as the Interface's object, I am getting a ClassCastException:
InsInterface4 obj=(InsInterface4) ht.get(str); How can I resolve the same? I have to call functions of the class but, I am not even able to cast properly? What is wrong in this?
Because you are putting a Class and you try to get an Interface4. If you want to have instances, rather than definitions inside the map, use: t.put(str, new ADC()). A few notes:
Hashtable<String, Interface4>.HashMap to Hashtablebackend.instructions.ADC.class is a Class, not an instance of that class.
You can do
Class<InsInterface4> clazz = (Class<InsInterface4>) ht.get(str); // if there is a default constructor InsInterface4 obj = (InsInterface4_ clazz.newInstance(); You have put the definition of the class in the table. You need to put actual instances of the class.
backend.instructions.ADC anAdc = new backend.instructions.ADC(); someOther.instructions.OTH anOth = new someOther.instructions.OTH(); ht.put("adc", anAdc); ht.put("oth", anOth); InsInterface4 obj=(InsInterface4) ht.get("adc"); 