使用正则表达式获取字符串中模式的索引

Question

我想在字符串中搜索特定模式。正则表达式类是否提供模式在字符串中的位置（字符串中的索引）？模式的出现次数可能超过1。有实际的例子吗？

Answer 1

Jean Logeart的特别版答案

public static int[] regExIndex(String pattern, String text, Integer fromIndex){

    Matcher matcher = Pattern.compile(pattern).matcher(text);

    if ( ( fromIndex != null && matcher.find(fromIndex) ) || matcher.find()) {

        return new int[]{matcher.start(), matcher.end()};

    }

    return new int[]{-1, -1};

}

Answer 2

import java.util.regex.Matcher;

import java.util.regex.Pattern;

public class RegexMatches

{

    public static void main( String args[] ){

      // String to be scanned to find the pattern.

      String line = "This order was places for QT3000! OK?";

      String pattern = "(.*)(\\d+)(.*)";

      // Create a Pattern object

      Pattern r = Pattern.compile(pattern);

      // Now create matcher object.

      Matcher m = r.matcher(line);

      if (m.find( )) {

         System.out.println("Found value: " + m.group(0) );

         System.out.println("Found value: " + m.group(1) );

         System.out.println("Found value: " + m.group(2) );

      } else {

         System.out.println("NO MATCH");

      }

   }

}

结果

Found value: This order was places for QT3000! OK?

Found value: This order was places for QT300

Found value: 0