Java字符串用求值键替换正则表达式模式

Question

我有一个这样的输入字符串

I want to go to {places} where {things} are happening.

{places}和{things}的值是惰性计算的（即，首先我找出需要替换的所有键，然后计算它们的值，然后在原始字符串中替换它们）

我能够找到所有的钥匙，并删除他们使用下面的代码

public class Temp {
    private static final Pattern betweenCurlyBracesMatcher = Pattern.compile("\\{(.*?)\\}");

    public static void main(String args[]) {
        System.out.println(resolve2("hello {world} from {here}"));
    }

    public static String resolve2(String input) {
        Map<String, String> keyValueMap = new HashMap<>();
        Matcher matcher = betweenCurlyBracesMatcher.matcher(input);
        while (matcher.find()) {
            String key = matcher.group(1);
            if (!keyValueMap.containsKey(key)) {
                keyValueMap.put(key, computeValueForKey(key));
            }
        }
        for (Map.Entry<String, String> entry : keyValueMap.entrySet()) {
            input = input.replace("{" + entry.getKey() + "}", entry.getValue());  // << ugly code here
        }
        return input;
    }

    private static String computeValueForKey(String key) {
        return "new" + key;
    }
}

但我不满意

input = input.replace("{" + entry.getKey() + "}", entry.getValue());

因为这意味着无论何时我改变我的正则表达式，我都必须更新这个逻辑。这个问题有没有更优雅的解决方案

---

输入你好{world}来自{here}

输出您好，这里是newhere的newworld

---

输入我想去{地方}，那里{事情}正在发生

输出我想去发生新事情的新地方

Answer 1

我们可以用matcher。返回entire matched string的组（0）

public class Temp {
    private static final Pattern betweenCurlyBracesMatcher = Pattern.compile("\\{(.*?)\\}");

    public static void main(String args[]) {
        System.out.println(resolve2("hello {world} from {here}"));
    }

    public static String resolve2(String input) {
        Map<String, String> keyValueMap = new HashMap<>();
        Matcher matcher = betweenCurlyBracesMatcher.matcher(input);
        while (matcher.find()) {
            String keyBetweenBraces = matcher.group(1);
            String keyWithBraces = matcher.group(0);
            if (!keyValueMap.containsKey(keyWithBraces)) {
                keyValueMap.put(keyWithBraces, computeValueForKey(keyBetweenBraces));
            }
        }
        for (Map.Entry<String, String> entry : keyValueMap.entrySet()) {
            input = input.replace(entry.getKey(), entry.getValue());
        }
        return input;
    }

    private static String computeValueForKey(String key) {
        return "new" + key;
    }
}