java - 使用 StringTokenizer 模拟 String.split

Question

我正在将现有应用程序的代码转换为针对定制硬件的 Java 1.1 编译器进行编译。这意味着我不能使用 String.split(regex) 将我现有的字符串转换为数组。

我创建了一个方法，它应该给出与 String.split(regex) 相同的结果，但它有问题，我不知道是什么。

代码:

private static String[] split(String delim, String line) {
  StringTokenizer tokens = new StringTokenizer(line, delim, true);
  String previous = "";
  Vector v = new Vector();

  while(tokens.hasMoreTokens()) {
    String token = tokens.nextToken();

    if(!",".equals(token)) {
      v.add(token);
    } else if(",".equals(previous)) {
      v.add("");
    } else {
      previous = token;
    }
  }

  return (String[]) v.toArray(new String[v.size()]);
}

示例输入:

RM^RES,0013A2004081937F,,9060,1234FF

示例输出:

String line = "RM^RES,0013A2004081937F,,9060,1234FF";
String[] items = split(",", line);

for(String s : items) {
    System.out.println(" [ " + s + " ] ");
}

[ RM^RES ] [ 0013A2004081937F ] [ ] [ ] [ 9060 ] [ ] [ 1234FF ]

期望的输出:

[ RM^RES ] [ 0013A2004081937F ] [ ] [ 9060 ] [ 1234FF ]

---

我正在尝试转换的旧代码:

String line = "RM^RES,0013A2004081937F,,9060,1234FF";
String[] items = line.split(",");

for(String s : items) {
    System.out.println(" [ " + s + " ] ");
}

[ RM^RES ] [ 0013A2004081937F ] [ ] [ 9060 ] [ 1234FF ]

Answer 1

我修改了代码并测试了它。它有效(不要忘记避免对“，”进行硬编码，因此您可以将该函数用于任何定界符):

private static String[] split(String delim, String line) {

    StringTokenizer tokens = new StringTokenizer(line, delim, true);
    String previous = delim;
    Vector v = new Vector();

    while (tokens.hasMoreTokens()) {
        String token = tokens.nextToken();

        if (!delim.equals(token)) {
            v.add(token);
        } else if (previous.equals(delim)) {
            v.add("");
        }
        previous = token;
    }

    return (String[]) v.toArray(new String[v.size()]);
}