Java Regex 不一致组 [英] Java Regex inconsistent groups
问题描述
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Please Refer to following question on SO:
我的正则表达式组不一致.我的代码看起来像:
My Regex groups are not consistent. My code looks like:
public class RegexTest {
public static void main(String[] args) {
// final String VALUES_REGEX = "^\\{([0-9a-zA-Z\\-\\_\\.]+)(?:,\\s*([0-9a-zA-Z\\-\\_\\.]*))*\\}$";
final String VALUES_REGEX = "\\{([\\w.-]+)(?:, *([\\w.-]+))*\\}";
final Pattern REGEX_PATTERN = Pattern.compile(VALUES_REGEX);
final String values = "{df1_apx.fhh.irtrs.d.rrr, ffd1-afp.farr.d.rrr.asgd, ffd2-afp.farr.d.rrr.asgd}";
final Matcher matcher = REGEX_PATTERN.matcher(values);
if (null != values && matcher.matches()) {
// for (int index=1; index<=matcher.groupCount(); ++index) {
// System.out.println(matcher.group(index));
// }
while (matcher.find()) {
System.out.println(matcher.group());
}
}
}
}
我尝试了以下组合:
A) 正则表达式为 "^\{([0-9a-zA-Z\-\_\.]+)(?:,\s*([0-9a-zA-Z\-\_\.]))\}$" 并使用 groupCount() 进行迭代.结果:
A) Regex as "^\{([0-9a-zA-Z\-\_\.]+)(?:,\s*([0-9a-zA-Z\-\_\.]))\}$" and use groupCount() to iterate. Result:
df1_apx.fhh.irtrs.d.rrr
ffd2-afp.farr.d.rrr.asgd
B) 正则表达式为 ^\{([0-9a-zA-Z\-\_\.]+)(?:,\s*([0-9a-zA-Z\-\_\.]))\}$" 并使用 matcher.find().结果:没有结果.
B) Regex as ^\{([0-9a-zA-Z\-\_\.]+)(?:,\s*([0-9a-zA-Z\-\_\.]))\}$" and use matcher.find(). Result: No result.
C) 正则表达式为 "\{([\w.-]+)(?:, ([\w.-]+))\}" 并使用 groupCount() 进行迭代.结果:
C) Regex as "\{([\w.-]+)(?:, ([\w.-]+))\}" and use groupCount() to iterate. Result:
df1_apx.fhh.irtrs.d.rrr
ffd2-afp.farr.d.rrr.asgd
D) 正则表达式为 "\{([\w.-]+)(?:, ([\w.-]+))\}" 并使用 matcher.find().结果:没有结果.
D) Regex as "\{([\w.-]+)(?:, ([\w.-]+))\}" and use matcher.find(). Result: No results.
我从来没有得到一致的群体.这里的预期结果是:
I never get consistent groups. Expected result here is:
df1_apx.fhh.irtrs.d.rrr
ffd1-afp.farr.d.rrr.asgd
ffd2-afp.farr.d.rrr.asgd
请告诉我，我怎样才能实现它.
Please let me know, how can I achieve it.
推荐答案
(?<=[{,])\s*(.*?)(?=,|})
您可以简单地使用它并抓取捕获.参见演示.
You can simply use this and grab the captures.See demo.
https://regex101.com/r/sJ9gM7/33
当您有 (#something)* 时，正则表达式引擎只会记住最后一组.您不会以这种方式获得所有组.
When you have (#something)* then only the last group is remembered by the regex engine.You wont get all the groups this way.
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