Java's Type API sample showing how to obtain the actual type of parameterized type.

gistfile1.java

import java.lang.reflect.Field;
import java.lang.reflect.GenericArrayType;
import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;
import java.util.List;

public class GenericTypeSample {
	public List<Integer>[] testField;
	
	public static void main(String[] args) throws Exception {
		new GenericTypeSample().run();
	}
	
	public void run() throws Exception {
		Field field = getClass().getField("testField");
		
		// Type of an array field is GenericArrayType
		Type fieldType = field.getGenericType();
		assert fieldType instanceof GenericArrayType;
		
		GenericArrayType genericArrayType = (GenericArrayType)fieldType;

		// Array's component type can be obtained.
		Type componentType = genericArrayType.getGenericComponentType();
		
		// In this case, the component type is ParameterizedType (List<Integer>).
		assert componentType instanceof ParameterizedType;

		// You can obtain actual type arguments from a ParameterizedType instance.
		ParameterizedType parameterizedType = (ParameterizedType)componentType;
		Type[] types = parameterizedType.getActualTypeArguments();
		assert types[0] == Integer.class;
	}
}