如何用java中的相应字符替换特定字符？ [复制]

Question

我想做这样的事情：将所有ck 替换为k，将所有dd 替换为wr，将所有f 替换为m，以及另外10 个这样的替换。 我可以用replace("ck","k").replace("dd","wr")等等来做到这一点，但它接缝很傻而且很慢。 java中是否有任何函数可以做这样的事情？ 例如replace(string,stringArray1, stringArray2);

Answer 1

使用appendReplacement 循环。

这是一种通用的方法：

private static String replace(String input, Map<String, String> mappings) {
    StringBuffer buf = new StringBuffer();
    Matcher m = Pattern.compile(toRegex(mappings.keySet())).matcher(input);
    while (m.find())
        m.appendReplacement(buf, Matcher.quoteReplacement(mappings.get(m.group())));
    return m.appendTail(buf).toString();
}
private static String toRegex(Collection<String> keys) {
    return keys.stream().map(Pattern::quote).collect(Collectors.joining("|"));
}

如果您不使用 Java 8+，则第二种方法是：

private static String toRegex(Collection<String> keys) {
    StringBuilder regex = new StringBuilder();
    for (String key : keys) {
        if (regex.length() != 0)
            regex.append("|");
        regex.append(Pattern.quote(key));
    }
    return regex.toString();
}

测试代码

Map<String, String> mappings = new HashMap<>();
mappings.put("ck","k");
mappings.put("dd","wr");
mappings.put("f", "m");
System.out.println(replace("odd flock", mappings)); // prints: owr mlok

查看IDEONE 了解运行版本。

Answer 2

Map<String, String> replacementMap = new HashMap<String, String>();
replacementMap.put("ck", "k");
replacementMap.put("dd", "wr");
replacementMap.put("f", "m");
// ...

String resultStr = "Abck fdddk wr fmck"; // whatever string to process
StringBuilder builder = new StringBuilder(resultStr); // wrap it in builder

Iterator<String> iterator = replacementMap.keySet().iterator();
while (iterator.hasNext()) {
    String strToReplace = iterator.next();
    replaceAll(builder, strToReplace, replacementMap.get(strToReplace));
}
System.out.println("Result is: " + builder.toString());

public static void replaceAll(StringBuilder builder, String from, String to) {
    int index = builder.indexOf(from);
    while (index != -1) {
        builder.replace(index, index + from.length(), to);
        index += to.length(); // Move to the end of the replacement
        index = builder.indexOf(from, index);
    }
}

replaceAll() 方法是从这个Jon Skeet's answer借来的

在他的示例中替换replaceAll() 是使用apache commons 库，有StrBuilder 类提供replaceAll() 方法。见this answer