在 Eclipse 中調用 Java 中的 Scala 代碼時發生錯誤

Question

我想在 Java 中調用以下 Scala 代碼：

斯卡拉代碼

package calculate

import java.io._

class CalculationScala

object CalculationScala {
  def main(args: Array[String]) {
    def operate(a: Double, b: Double, op: (Double, Double) => Double): Double = (op(a, b))
    println(operate(5, 15, _-_))
  }
}

Java代碼

package calculate;

public class Calculation {
    public static void main(String[] args) {
        CalculationScala calculationScala = new CalculationScala();
        calculationScala.main(args);
    }
}

但出現以下錯誤。

錯誤

Exception in thread "main" java.lang.NoClassDefFoundError: scala/Function2
    at calculate.CalculationScala.main(CalculationScala.scala)
    at calculate.Calculation.main(Calculation.java:79)
Caused by: java.lang.ClassNotFoundException: scala.Function2
    at java.net.URLClassLoader$1.run(URLClassLoader.java:366)
    at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:425)
    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:358)
    ... 2 more

如何解決這個問題？

Answer 1

看起來您的運行時類路徑中缺少 scala-library.jar。