How to Instantiate Generic Types in Java: A Guide to Runtime Type Specificity

Instantiating Generic Types in Java: Unveiling a Seemingly Trivial Conundrum

While instantiating generic types in Java may appear straightforward, the underlying mechanisms can be surprisingly nuanced. This article elaborates on the technique to instantiate an object of a generic type, delving into the intricacies of Java's generic system.

Given a generic class declaration like:

public class Abc<T> {
    public T getInstanceOfT() {
       // Instantiate an instance of T and return it.
    }
}

To instantiate an object of type T, the type information needs to be provided explicitly at runtime. This is achieved using the Class object:

public class Abc<T> {
    public T getInstanceOfT(Class<T> aClass) {
       return aClass.newInstance();
    }
}

When calling this method, the actual type parameter must be specified:

Abc<String> abc = new Abc<>();
String instance = abc.getInstanceOfT(String.class);

Note that exception handling is required to manage potential instantiation failures.

This approach allows flexibility in runtime instantiation, as the generic type can vary dynamically based on the calling code.

The above is the detailed content of How to Instantiate Generic Types in Java: A Guide to Runtime Type Specificity. For more information, please follow other related articles on the PHP Chinese website!