Regex Test Harness : Introduction « Regular Expressions « Java Tutorial

1. Java Tutorial
2. Regular Expressions
3. Introduction

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import java.io.Console;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class RegexTestHarness {

  public static void main(String[] args) {
    Console console = System.console();
    if (console == null) {
      System.err.println("No console.");
      System.exit(1);
    }
    while (true) {

      Pattern pattern = Pattern.compile(console
          .readLine("%nEnter your regex: "));

      Matcher matcher = pattern.matcher(console
          .readLine("Enter input string to search: "));

      boolean found = false;
      while (matcher.find()) {
        console.format("I found the text \"%s\" starting at "
            + "index %d and ending at index %d.%n", matcher.group(), matcher
            .start(), matcher.end());
        found = true;
      }
      if (!found) {
        console.format("No match found.%n");
      }
    }
  }
}