Regular expression, replace whitespaces inside tag

问题

I have an incorrect xml string and I would like to build a correct one

<root val="yyy">
    <fol der val="attribute 1">myfolder</folder>
</root>

The problem is the white space inside tag: "fol der". It's possible to replace white spaces inside < > tags(but not inside attributes) using regular expression in java? Thanks to all

回答1:

If your XML is like this:

<root val="yyy">
    <fo l der val="attribute 1">myfol d er</folder>
</root>

Following should work:

final Pattern p = Pattern.compile("(?s)(?<=<).*?(?=/?>|\\s*\\w+\\s*=)");
Matcher m = p.matcher(data); // your XML
StringBuffer sb = new StringBuffer();
while (m.find()) {
    m.appendReplacement(sb, m.group().replace(" ", ""));
}
m.appendTail(sb);
data = sb.toString();
System.out.println(data);

OUTPUT:

<root val="yyy">
    <folder val="attribute 1">myfol d er</folder>
</root>

Live Demo: http://ideone.com/TIrsQR

回答2:

I would have used (?<=[<]\w*)\s+ but java's regex engine doesn't support quantifiers in lookbehind..

You would have to do this if there are multiple spaces.

Matcher m=Pattern.compile("(?<=[<])(/?)\\s*(\\w*)\\s+(?!\\w+\\s*=)").matcher(xml);
while(m.find())
{
    xml=m.replaceAll("$1$2");
    m.reset(xml);   
}

Though this won't work for attribute names

回答3:

Probably not what you want to hear, but this is a wrong tool for solving the wrong problem. The rule of thumb is, do not try to parse/process XML files yourself with regular expressions. If you got an incorrect/invalid XML, that is the problem you should be solving with the one who provided it, not how to fix it.

来源：https://stackoverflow.com/questions/19095106/regular-expression-replace-whitespaces-inside-tag

标签

java

regex