java - Java的shlex替代品

Question

Java有shlex替代品吗？我希望能够像 shell 处理它们一样拆分引号分隔的字符串。例如，如果我发送：

一二三四”

并执行拆分，我想收到令牌

一二三四
_

Answer 1

我今天遇到了类似的问题，它看起来不像任何标准选项，如 StringTokenizer、StrTokenizer、Scanner 都非常适合。但是，实现基础并不难。

此示例处理当前在其他答案上评论的所有边缘情况。请注意，我还没有检查它是否完全符合 POSIX。Gist 包括GitHub 上可用的单元测试- 通过未经许可在公共领域发布。

public List<String> shellSplit(CharSequence string) {
    List<String> tokens = new ArrayList<String>();
    boolean escaping = false;
    char quoteChar = ' ';
    boolean quoting = false;
    int lastCloseQuoteIndex = Integer.MIN_VALUE;
    StringBuilder current = new StringBuilder();
    for (int i = 0; i<string.length(); i++) {
        char c = string.charAt(i);
        if (escaping) {
            current.append(c);
            escaping = false;
        } else if (c == '\\' && !(quoting && quoteChar == '\'')) {
            escaping = true;
        } else if (quoting && c == quoteChar) {
            quoting = false;
            lastCloseQuoteIndex = i;
        } else if (!quoting && (c == '\'' || c == '"')) {
            quoting = true;
            quoteChar = c;
        } else if (!quoting && Character.isWhitespace(c)) {
            if (current.length() > 0 || lastCloseQuoteIndex == (i - 1)) {
                tokens.add(current.toString());
                current = new StringBuilder();
            }
        } else {
            current.append(c);
        }
    }
    if (current.length() > 0 || lastCloseQuoteIndex == (string.length() - 1)) {
        tokens.add(current.toString());
    }

    return tokens;
}

Answer 2

看看Apache Commons Lang：

org.apache.commons.lang.text.StrTokenizer应该能够做你想做的事：

new StringTokenizer("一二\"三四\"", '', '"').getTokenArray();

Answer 3

我使用fastparse使用以下 Scala 代码取得了成功。我不能保证它是完整的：

val kvParser = {
  import fastparse._
  import NoWhitespace._
  def nonQuoteChar[_:P] = P(CharPred(_ != '"'))
  def quotedQuote[_:P] = P("\\\"")
  def quotedElement[_:P] = P(nonQuoteChar | quotedQuote)
  def quotedContent[_:P] = P(quotedElement.rep)
  def quotedString[_:P] = P("\"" ~/ quotedContent.! ~ "\"")
  def alpha[_:P] = P(CharIn("a-zA-Z"))
  def digit[_:P] = P(CharIn("0-9"))
  def hyphen[_:P] = P("-")
  def underscore[_:P] = P("_")
  def bareStringChar[_:P] = P(alpha | digit | hyphen | underscore)
  def bareString[_:P] = P(bareStringChar.rep.!)
  def string[_:P] = P(quotedString | bareString)
  def kvPair[_:P] = P(string ~ "=" ~ string)
  def commaAndSpace[_:P] = P(CharIn(" \t\n\r").rep ~ "," ~ CharIn(" \t\n\r").rep)
  def kvPairList[_:P] = P(kvPair.rep(sep = commaAndSpace))
  def fullLang[_:P] = P(kvPairList ~ End)

  def res(str: String) = {
    parse(str, fullLang(_))
  }

  res _
}