Scala, sugar in Java : make a type parametrized factory

2010/09/14 | Published in , ,

The basic code to create an instance from a Type parameter :

(full source on github )

// Scala

  def newOne[T]()(implicit m: Manifest[T]): T = {
    // assume T as a no-args constructor
    m.erasure.newInstance().asInstanceOf[T]
  }

// sample call
  val v = newOne[String]()

// Java

  public <T> T newOne(Class<T> clazz) {
    return clazz.newInstance();
  }
  
// sample call from java
  String v = newOne(String.class);
  
// sample call from scala
  val v = newOne(classOf[String])