Question

From the below string, I need NUM = 12122 and CheckFrom = 02453226170 only

String s="shopNumber = \"shop 1\", NUM = \"12122\", Reference = \"NUM1\", CheckFrom = \"02453226170\""

how can I do this using regular expression and replaceall function of String class?

Answer 1

Using Matcher.find would make this task a lot easier to extract out the name/value pairs. Essentially you are looking for the pattern word = "number":

Matcher m = Pattern.compile("(\\w+) = \"(\\d+)\"").matcher(s);
StringBuilder builder = new StringBuilder();
while (m.find()) {
   builder.append(m.group(1));
   builder.append("=");
   builder.append(m.group(2));
   builder.append(" ");
}

m.group(1) relates to the first captured group, (i.e. the match from the word \w+)

Builder contains:

NUM=12122 CheckFrom=02453226170

Update:
From your question in the comments, you could use instead:

Pattern.compile("(NUM = \"\\d+\").*( CheckFrom = \"\\d+\")")

and append the 2 groups together to get your String.