java - StringTokenizer 错误

Question

这是我第一次将分词器用于各种分数计算器。我尽可能地尝试了以下语法，但得到了这个丑陋的错误:

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

传递给构造函数的第一个参数必须是 String。它是一个 Fraction，而不是一个 String。找到将其转换为 String 的方法，Java 编译器无法为您完成此操作，并且在不了解 Fraction 类型的情况下几乎无法提供建议。