Java 在单词中间用引号分隔字符串

Question

我非常感谢 Java 代码的一些帮助来拆分以下输入:

word1 key="value with space" word3 -> [ "word1", "key=\"value with space\"", "word3" ]
word1 "word2 with space" word3 -> [ "word1", "word2 with space", "word3" ]
word1 word2 word3 -> [ "word1" , "word2", "word3" ]

第一个样本输入是困难的。第二个单词在字符串中间而不是开头有引号。我找到了几种处理中间示例的方法，如 Split string on spaces in Java, except if between quotes (i.e. treat \"hello world\" as one token) 中所述。

Answer 1

而不是完全使用正则表达式，您可以对字符串进行简单的迭代:

public static String[] splitWords(String str) {
        List<String> array = new ArrayList<>(); 
        boolean inQuote = false; // Marker telling us if we are between quotes
        int previousStart = -1;  // The index of the beginning of the last word
        for (int i = 0; i < str.length(); i++) {
            char c = str.charAt(i);
            if (Character.isWhitespace(c)) {
                if (previousStart != -1 && !inQuote) {
                    // end of word
                    array.add(str.substring(previousStart, i));
                    previousStart = -1;
                }
            } else {
                // possibly new word
                if (previousStart == -1) previousStart = i;
                // toggle state of quote
                if (c == '"')
                    inQuote = !inQuote;
            }
        }
        // Add last segment if there is one
        if (previousStart != -1) 
            array.add(str.substring(previousStart));
        return array.toArray(new String [array.size()]);
    }

此方法的优点是能够根据需要多次正确识别远离空格的引号。例如，以下是单个字符串:

a"b c"d"e f"g