I have the below java string in the below format.
String s = "City: [name:NYK][distance:1100] [name:CLT][distance:2300] [name:KTY][distance:3540] Price:"
Using the java.util.regex package matter and pattern classes I have to get the output string int the following format:
Output: [NYK:1100][CLT:2300][KTY:3540]
Can you suggest a RegEx pattern which can help me get the above output format?
You can use this regex \[name:([A-Z]+)\]\[distance:(\d+)\] with Pattern like this :
String regex = "\\[name:([A-Z]+)\\]\\[distance:(\\d+)\\]";
Pattern pattern = Pattern.compile(regex);
Matcher matcher = pattern.matcher(s);
StringBuilder result = new StringBuilder();
while (matcher.find()) {
result.append("[");
result.append(matcher.group(1));
result.append(":");
result.append(matcher.group(2));
result.append("]");
}
System.out.println(result.toString());
Output
[NYK:1100][CLT:2300][KTY:3540]
\[name:([A-Z]+)\]\[distance:(\d+)\] mean get two groups one the upper letters after the \[name:([A-Z]+)\] the second get the number after \[distance:(\d+)\] Another solution from @tradeJmark you can use this regex :
String regex = "\\[name:(?<name>[A-Z]+)\\]\\[distance:(?<distance>\\d+)\\]";
So you can easily get the results of each group by the name of group instead of the index like this :
while (matcher.find()) {
result.append("[");
result.append(matcher.group("name"));
//----------------------------^^
result.append(":");
result.append(matcher.group("distance"));
//------------------------------^^
result.append("]");
}
name:(?<name>[A-Z]+), and then accessed as matcher.group("name"). Just makes it really clear at the access point exactly what segment you're trying to access.
name:(?<name>[A-Z]+), and then accessed as matcher.group("name") honestly it is the first time i see it, i already test it and it work very well String regex = "\\[name:(?<name>[A-Z]+)\\]\\[distance:(?<distance>\\d+)\\]"; i will add to my answer if you don't mind :)If the format of the string is fixed, and you always have just 3 [...] groups inside to deal with, you may define a block that matches [name:...] and captures the 2 parts into separate groups and use a quite simple code with .replaceAll:
String s = "City: [name:NYK][distance:1100] [name:CLT][distance:2300] [name:KTY][distance:3540] Price:";
String matchingBlock = "\\s*\\[name:([A-Z]+)]\\[distance:(\\d+)]";
String res = s.replaceAll(String.format(".*%1$s%1$s%1$s.*", matchingBlock),
"[$1:$2][$3:$4][$5:$6]");
System.out.println(res); // [NYK:1100][CLT:2300][KTY:3540]
See the Java demo and a regex demo.
The block pattern matches:
\\s* - 0+ whitespaces\\[name: - a literal [name: substring([A-Z]+) - Group n capturing 1 or more uppercase ASCII chars (\\w+ can also be used) ]\\[distance: - a literal ][distance: substring(\\d+) - Group m capturing 1 or more digits] - a ] symbol.In the .*%1$s%1$s%1$s.* pattern, the groups will have 1 to 6 IDs (referred to with $1 - $6 backreferences from the replacement pattern) and the leading and final .* will remove start and end of the string (add (?s) at the start of the pattern if the string can contain line breaks).
