Regex to find a word if it presents java

Question

I have a file with structured data but it may have a missing field as follows

Name:xxxxx,Age:20,Gender:Male
Name:yyyy,Gender:male
Name:zzzx,Age:26,Gender:Male

I want a single regex to get the values of name,age and gender. So far I have used

Name:(.*),Age:(.*),Gender:(.*)

which brings the values if all three fields exists but it doesnt works for the missing fileds. can anyone tell me how to achieve this

Answer 1

Are you using Java's Pattern and Matcher classes? If so, you can do a regular expression like so.

(Name:(.*),)?(Age:(.*),)?(Gender:(.*),)?

This will mess up your grouping some but should give the correct results. The reason this works is because when you use a '?' it finds zero or one instances of what it's looks for. So this is perfect for what you are doing.

Answer 2

Split on , and : to get all key-value pairs.

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

public class SOPlayground {

    public static void main(String[] args) throws Exception {
        String input = "Name:xxxxx,Age:20,Gender:Male\n"
                + "Name:yyyy,Gender:male\n"
                + "Name:zzzx,Age:26,Gender:Male";

        List<Map<String, String>> entries = new ArrayList<>();
        for (String line : input.split("\n")) {
            Map<String, String> entry = new HashMap<>();
            for (String field : line.split(",")) {
                String[] parts = field.split(":");
                String key = parts[0];
                String value = parts[1];
                entry.put(key, value);
            }
            entries.add(entry);
        }
        System.out.println(entries);
    }

}

Output:

[{Gender=Male, Age=20, Name=xxxxx}, {Gender=male, Name=yyyy}, {Gender=Male, Age=26, Name=zzzx}]

Answer 3

Try out something like:

String str = "Name:xxxxx,Age:20,Gender:Male";
String regex = "Name:(.*?[^,]),Age:(.*?[^,]),Gender:(.*)"; 
...
Output:
xxxxx
20
Male