如何在Java中使用Scala单例对象？

I have a Scala object that I need to use in a Java class.

我有一个Scala对象,我需要在Java类中使用。

Here's the Scala object

这是Scala对象

object Person {
  val MALE = "m"
  val FEMALE = "f"
}

How can I use this Scala object in Java?

如何在Java中使用此Scala对象?

I have tried the following so far without success (compile errors):

到目前为止我已经尝试了以下但没有成功(编译错误):

• Person.MALE() //returns a String which is useless as I want the actual Person object

Person.MALE()//返回一个无用的String,因为我想要实际的Person对象

2 个解决方案

#1

Use Person$.MODULE$. See also

使用Person $ .MODULE $。也可以看看

• How can I pass a Scala object reference around in Java?

如何在Java中传递Scala对象引用?

• Singletons as Synthetic classes in Scala?

单身作为Scala中的合成类?

---

Edit: A working example (I checked, it compiles and works): Scala:

编辑:一个工作示例(我检查,它编译和工作):Scala:

object Person {
  val MALE = "m";
}

Java counterpart:

public class Test {
    Person$ myvar = Person$.MODULE$;

    public static void main(String argv[]) {
        System.out.println(new Test().myvar.MALE());
    }
}

#2

In case you use a package object, the access is a bit different

如果您使用包对象,则访问权限会有所不同

Scala:

package my.scala.package

package object Person {
  val MALE = "m";
}

Java counterpart:

public static void main() {
  System.out.println(my.scala.package.Person.package$.MODULE$.MALE);
}