java, treque, instantiating an array with class t

Question

I have a class which has the constructor

public Treque(Class<T> t) {
}

I need to instantiate an array which has the class t. How do I instantiate it?

• JB Nizet: docs.oracle.com/javase/8/docs/api/java/lang/reflect/…

Answer 1

It depends on what your exact goal is. If you want something arbitrary, go with reflection. If you simply want to pass an object that inherits a class, you can do that with different syntax.

Since your example is using Class, try these reflection examples:

• http://docs.oracle.com/javase/tutorial/reflect/member/methodInvocation.html
• Is there a way to instantiate a class by name in Java?

I think the accepted answer here is what you are looking for. Java Generics Creating Array from Class

And a little bit more:

 public void test(Class<T> t) {
 T[] a=new T[10];//complie error
 Object array = java.lang.reflect.Array.newInstance(t, 10);//lots of ambiguity
 String[] arrT = (String[]) array;//works if you know the final type
 Object[] anyType = new Object[10];
 for(int i=0;i<10;i++)
 anyType[i] = createObject(t.getName());
 //You will need to cast the Object to your desired type
 }
 static Object createObject(String className) {
 //http://www.java2s.com/Code/Java/Reflection/ObjectReflectioncreatenewinstance.htm
 Object object = null;
 try {
 Class classDefinition = Class.forName(className);
 object = classDefinition.newInstance();
 } catch (InstantiationException e) {
 System.out.println(e);
 } catch (IllegalAccessException e) {
 System.out.println(e);
 } catch (ClassNotFoundException e) {
 System.out.println(e);
 }
 return object;
 }