import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class Example {
public static void main(String[] args) {
final String regex = "^((\\()(?1)?(\\))(?1)?)$";
final String string = "//SHOULD\n"
+ "()\n"
+ "(())\n"
+ "((()))\n"
+ "()()\n"
+ "(())()\n"
+ "()()()\n"
+ "()()()()()\n"
+ "(((())))\n"
+ "()((()))\n"
+ "()()()()((()))(())((()))(((((((())))))))\n\n\n"
+ "//NOT\n"
+ "(\n"
+ ")\n"
+ ")(\n"
+ "))((\n"
+ ")()(\n"
+ "(()\n"
+ "))\n"
+ "())\n"
+ "(()\n"
+ "()()())\n"
+ "()())\n"
+ ")))))))))\n"
+ "((((((((\n\n";
final Pattern pattern = Pattern.compile(regex, Pattern.MULTILINE);
final Matcher matcher = pattern.matcher(string);
while (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