JavaStream 和可选 查找与流元素匹配的值或提供默认值

我有一个Dictionary对象，它由几个条目组成:

record Dictionary(String key, String value, String other) {};

我想用相应的值替换给定的Stringmy a中的单词，这些单词在其中一个词典中作为关键字出现.我可以像这样实现，但我想，肯定有更好的方法来做到这一点.

举个例子:

> Input: One <sup>a</sup> Two <sup>b</sup> Three <sup>D</sup> Four
> Output: One [a-value] Two [b-value] Three [D] Four

需要改进的代码:

public class ReplaceStringWithDictionaryEntries {
    public static void main(String[] args) {
        List<Dictionary> dictionary = List.of(new Dictionary("a", "a-value", "a-other"),
                new Dictionary("b", "b-value", "b-other"));
        String theText = "One <sup>a</sup> Two <sup>b</sup> Three <sup>D</sup> Four";
        Matcher matcher = Pattern.compile("<sup>([A-Za-z]+)</sup>").matcher(theText);
        StringBuilder sb = new StringBuilder();
        int matchLast = 0;
        while (matcher.find()) {
            sb.append(theText, matchLast, matcher.start());
            Optional<Dictionary> dict = dictionary.stream().filter(f -> f.key().equals(matcher.group(1))).findFirst();
            if (dict.isPresent()) {
                sb.append("[").append(dict.get().value()).append("]");
            } else {
                sb.append("[").append(matcher.group(1)).append("]");
            }

            matchLast = matcher.end();
        }
        if (matchLast != 0) {
            sb.append(theText.substring(matchLast));
        }
        System.out.println("Result: " + sb.toString());
    }
}

Output:个

Result: One [a-value] Two [b-value] Three [D] Four

你有没有更优雅的方式做这件事？