Java Regex检查字符串是否包含XML标记

Question

I am trying to determine if a string contains at least one XML tag using the String.match() function. Due to the way the project is set up, I would prefer if I didn't have to use a Pattern .

Currently I use this Regex:

<[A-Za-z0-9]+>

Which obviously only checks if the string has right and left arrow brackets that contains text. What I need is a way to check if the string just has a single XML tag with Regex, eg input like:

blah <abc foo="bar">blah</abc> blah
blah <abc foo="bar"/>

but not input like:

blah <abc> blah
blah <abc </abc> blah

Is that possible?

Answer 1

This:

if (input.matches("(?s).*(<(\\w+)[^>]*>.*</\\2>|<(\\w+)[^>]*/>).*"))

matches both types of tag (standard and self-closing):

<abc foo="bar">blah</abc>
<abc foo="bar"/>

without matching incomplete tags like:

<abc>

See regex live demo .

Answer 2

You can use:

if (input.matches("(?s).*?<(\\S+?)[^>]*>.*?</\\1>.*")) {
    // String has a XML tag
}

(?s) is DOTALL flag to make DOT match newlines also.

RegEx Demo

Answer 3

Ok, this regex will match most html/xml tags.
Probably only need node tags, the rest can be peeled off.

Just node tags (final edit) -

 # "(?s)<(?:/?[\\w:]+\\s*|[\\w:]+(?:\".*?\"|'.*?'|[^>]*?)+)>"

 (?s)
 <
 (?:
      /?
      [\w:]+ 
      \s* 
   |  
      [\w:]+ 
      (?: " .*? " | ' .*? ' | [^>]*? )+
 )
 >

Full -

Formatted:

 # "<(?:(?:/?[\\w:]+\\s*/?)|(?:[\\w:]+\\s+(?:(?:(?:\"[\\S\\s]*?\")|(?:'[\\S\\s]*?'))|(?:[^>]*?))+\\s*/?)|\\?[\\S\\s]*?\\?|(?:!(?:(?:DOCTYPE[\\S\\s]*?)|(?:\\[CDATA\\[[\\S\\s]*?\\]\\])|(?:--[\\S\\s]*?--)|(?:ATTLIST[\\S\\s]*?)|(?:ENTITY[\\S\\s]*?)|(?:ELEMENT[\\S\\s]*?))))>"

 <
 (?:
      (?:
           /? 
           [\w:]+ 
           \s* 
           /? 
      )
   |  
      (?:
           [\w:]+ 
           \s+ 
           (?:
                (?:
                     (?: " [\S\s]*? " )
                  |  (?: ' [\S\s]*? ' )
                )
             |  (?: [^>]*? )
           )+
           \s* 
           /? 
      )
   |  
      \?
      [\S\s]*? 
      \?
   |  
      (?:
           !
           (?:
                (?:
                     DOCTYPE
                     [\S\s]*? 
                )
             |  (?:
                     \[CDATA\[
                     [\S\s]*? 
                     \]\]
                )
             |  (?:
                     --
                     [\S\s]*? 
                     --
                )
             |  (?:
                     ATTLIST
                     [\S\s]*? 
                )
             |  (?:
                     ENTITY
                     [\S\s]*? 
                )
             |  (?:
                     ELEMENT
                     [\S\s]*? 
                )
           )
      )
 )
 >