我可以替换Java regex中的组吗？
我可以替换Java regex中的组吗？
提问于 2009-06-12 19:39:19
我有这段代码，我想知道是否可以在Java regex中仅替换组(不是所有模式)。代码：
//...
Pattern p = Pattern.compile("(\\d).*(\\d)");
String input = "6 example input 4";
Matcher m = p.matcher(input);
if (m.find()) {
//Now I want replace group one ( (\\d) ) with number
//and group two (too (\\d) ) with 1, but I don't know how.
}回答 3
Stack Overflow用户
发布于 2010-06-09 22:13:52
您可以使用matcher.start()和matcher.end()方法来获取组位置。因此，使用这些位置，您可以轻松地替换任何文本。
Stack Overflow用户
发布于 2018-11-22 17:49:47
替换输入中的密码字段：
{"_csrf":["9d90c85f-ac73-4b15-ad08-ebaa3fa4a005"],"originPassword":["uaas"],"newPassword":["uaas"],"confirmPassword":["uaas"]}
private static final Pattern PATTERN = Pattern.compile(".*?password.*?\":\\[\"(.*?)\"\\](,\"|}$)", Pattern.CASE_INSENSITIVE);
private static String replacePassword(String input, String replacement) {
Matcher m = PATTERN.matcher(input);
StringBuffer sb = new StringBuffer();
while (m.find()) {
Matcher m2 = PATTERN.matcher(m.group(0));
if (m2.find()) {
StringBuilder stringBuilder = new StringBuilder(m2.group(0));
String result = stringBuilder.replace(m2.start(1), m2.end(1), replacement).toString();
m.appendReplacement(sb, result);
}
}
m.appendTail(sb);
return sb.toString();
}
@Test
public void test1() {
String input = "{\"_csrf\":[\"9d90c85f-ac73-4b15-ad08-ebaa3fa4a005\"],\"originPassword\":[\"123\"],\"newPassword\":[\"456\"],\"confirmPassword\":[\"456\"]}";
String expected = "{\"_csrf\":[\"9d90c85f-ac73-4b15-ad08-ebaa3fa4a005\"],\"originPassword\":[\"**\"],\"newPassword\":[\"**\"],\"confirmPassword\":[\"**\"]}";
Assert.assertEquals(expected, replacePassword(input, "**"));
}Stack Overflow用户
发布于 2018-01-23 16:20:10
这里有一个不同的解决方案，它也允许在多个匹配中替换单个组。它使用堆栈来颠倒执行顺序，因此可以安全地执行字符串操作。
private static void demo () {
final String sourceString = "hello world!";
final String regex = "(hello) (world)(!)";
final Pattern pattern = Pattern.compile(regex);
String result = replaceTextOfMatchGroup(sourceString, pattern, 2, world -> world.toUpperCase());
System.out.println(result); // output: hello WORLD!
}
public static String replaceTextOfMatchGroup(String sourceString, Pattern pattern, int groupToReplace, Function<String,String> replaceStrategy) {
Stack<Integer> startPositions = new Stack<>();
Stack<Integer> endPositions = new Stack<>();
Matcher matcher = pattern.matcher(sourceString);
while (matcher.find()) {
startPositions.push(matcher.start(groupToReplace));
endPositions.push(matcher.end(groupToReplace));
}
StringBuilder sb = new StringBuilder(sourceString);
while (! startPositions.isEmpty()) {
int start = startPositions.pop();
int end = endPositions.pop();
if (start >= 0 && end >= 0) {
sb.replace(start, end, replaceStrategy.apply(sourceString.substring(start, end)));
}
}
return sb.toString();
}页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/988655
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