Java使用正则表达式如何实现查找文本功能

package reMatch;import java.util.regex.Matcher;import java.util.regex.Pattern;public class REMatch {  public static void main(String[] args) {    String patt = "Q[^u]\\d+\\.";    Pattern r = Pattern.compile(patt);    String line = "Order QT300. Now! QT400.";    Matcher m = r.matcher(line);    while (m.find()) {      // group(0)或group()将会返回整个匹配的字符串（完全匹配）；group(i)则会返回与分组i匹配的字符      // 这个例子只有一个分组      System.out.println(patt + " matches \"" + m.group(0) + "\" in \"" + line + "\"");      System.out.println("start:" + m.start() + " end:" + m.end());    }  }}