OnJava8-Examples/arrays/ParameterizedArrayType.java

// arrays/ParameterizedArrayType.java
// (c)2017 MindView LLC: see Copyright.txt
// We make no guarantees that this code is fit for any purpose.
// Visit http://OnJava8.com for more book information.

class ClassParameter<T> {
  public T[] f(T[] arg) { return arg; }
}

class MethodParameter {
  public static <T> T[] f(T[] arg) { return arg; }
}

public class ParameterizedArrayType {
  public static void main(String[] args) {
    Integer[] ints = { 1, 2, 3, 4, 5 };
    Double[] doubles = { 1.1, 2.2, 3.3, 4.4, 5.5 };
    Integer[] ints2 =
      new ClassParameter<Integer>().f(ints);
    Double[] doubles2 =
      new ClassParameter<Double>().f(doubles);
    ints2 = MethodParameter.f(ints);
    doubles2 = MethodParameter.f(doubles);
  }
}