StringTokenizer错误

Question

这是我第一次将tokenizer用于分数计算器。 我尝试了以下语法，但出现了这个丑陋的错误：

Fraction.java:78: error: no suitable constructor found for 
StringTokenizer(Fraction,String,boolean)
    StringTokenizer parser = new StringTokenizer(oldMeasure, "/", true);                             
constructor StringTokenizer.StringTokenizer(String) is not applicable
  (actual and formal argument lists differ in length)
constructor StringTokenizer.StringTokenizer(String,String) is not applicable
  (actual and formal argument lists differ in length)
constructor StringTokenizer.StringTokenizer(String,String,boolean) is not applicable
  (actual argument Fraction cannot be converted to String by method invocation conversion)

这是代码

    public void read(Scanner theKeyboard)
    {
    StringTokenizer parser = new StringTokenizer(oldMeasure, "/");
    if(parser.countTokens() !=2)
        throw new RuntimeException("bad format for fraction");
    myNumerator = Integer.parseInt(parser.nextToken());
    myDenominator = Integer.parseInt(parser.nextToken());
    }

Answer 1

您在构造函数中传递的第一个参数必须是String 。 它是一个Fraction ，而不是String 。 找到将其转换为String ，Java编译器无法为您做到这一点，并且在不了解Fraction类型的情况下几乎没有建议。