import java.util.*;
import java.util.regex.*;
 
class Test
{
	public static void main (String[] args) throws java.lang.Exception
	{
		String regex = "(?<=cn=)[^,|]+(?=,ou=tged,ou=groupes,o=choregie,c=fr)";
        String string = "cn=doc_medical,ou=tged,ou=groupes,o=choregie,c=fr|cn=test,ou=test,ou=test,o=choregie,c=fr|cn=doc_confidentiel,ou=tged,ou=groupes,o=choregie,c=fr|cn=test,ou=test,ou=test,o=choregie,c=fr";
        Pattern pattern = Pattern.compile(regex);
        Matcher matcher = pattern.matcher(string);
        while (matcher.find()) {
            System.out.println(matcher.group(0));
        }
	}
}

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