import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class Example {
public static void main(String[] args) {
final String regex = "^(\\d*)(-)?(\\d*)?$";
final String string = "3\n"
+ "1000\n"
+ "15-20\n"
+ "20-15\n"
+ "10-20/2\n"
+ "1-1000/20\n"
+ "Above should be legal; this and below should be illegal\n"
+ " 3 \n"
+ "03\n"
+ "2 43\n"
+ "2x3\n"
+ "23x\n"
+ " 15 - 20 \n"
+ "15--30\n"
+ "15-03\n"
+ "15-20-30\n"
+ "1 5-20\n"
+ "15-2 0\n"
+ "15-/20\n"
+ "15/2-2\n"
+ "15/10/2";
final Pattern pattern = Pattern.compile(regex, Pattern.MULTILINE);
final Matcher matcher = pattern.matcher(string);
if (matcher.find()) {
System.out.println("Full match: " + matcher.group(0));
for (int i = 1; i <= matcher.groupCount(); i++) {
System.out.println("Group " + i + ": " + matcher.group(i));
}
}
}
}
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for Java, please visit: https://docs.oracle.com/javase/7/docs/api/java/util/regex/Pattern.html