Question

I have a method in a C# project that looks like this

public T AddEC<T>() where T : EntityComponent, new() {
    if (!HasEC<T>())
    {
      T nComponent = new T();
    }
}

Now I have only recently started properly working with Java Generics, but I have no idea how i’d port a method like this, or if its even possible due to the language constraints, can anyone help?

Answer 1

This is a very good article.

http://www.jprl.com/Blog/archive/development/2007/Aug-31.html

From that source

Java type and method constraints are specified using a “mini
expression language” within the ‘<‘ and ‘>’ declaring the generic type
parameters. For each type parameter that has constraints, the syntax
is:

TypeParameter ListOfConstraints 

Where ListOfConstraints is a ‘&’-separated list of one of the
following constraints:

• Specifying a base class or implemented interface on the Generic
  Type Argument by using: extends BaseOrInterfaceType

(‘&’ must be used instead of ‘,’ because ‘,’ separates each generic
type parameter.)