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javaclassloader

How to us a custom ClassLoader to get different and new objects from a library in Java

I want to get new instances of classes that exist inside a library. The library has different classes inherited from one parent class, and I need to get new instances of the child classes. I can provide precisely the class name as a text.

More specifically, I need to create objects of different HL7-v2 messages types from the hapi-base library. It has AbstractMessage class as the parent, while its child classes are ADT_A01, ADT_A02,... etc. I need to create ADT_A01(), ADT_A02()...etc objects from it.

How can I achieve this by using a Class Loader? If not, why?

Solution 
  • Class hl7MessageClass = getClass().getClassLoader().loadClass("package_name"+hl7MessageType);
return (AbstractMessage) hl7MessageClas.newInstance();