Possible Duplicate:
define your own exceptions with overloaded constructors in scala




我想编写一个Scala异常类，该类继承Java Exception类的子类，并提供类似的构造函数（每个构造函数都调用相应的Exception ctor。即，我将如何编写与该Java类等效的Scala：

public class MyException extends java.lang.Exception {
    public MyException () {
    }

    public MyException (String msg) {
        super(msg);
    }

    public MyException (Throwable e) {
        super(e);
    }

    public MyException (String msg, Throwable cause) {
        super(msg, cause);
    }
}

这似乎与this question有关，但是其中的答案并不令人满意（因为实际上未定义子类）。

如何使用默认值（空）？

class YourException (msg:String=null, cause:Throwable=null)
  extends java.lang.Exception (msg, cause) {}