Java如何使用正则表达式实现替换文本功能

package replaceDemo;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
/**
 * Created by Frank
 * 替换匹配的文本
 */
public class ReplaceDemo {
 public static void main(String[] args) {
  // 创建一个正则表达式模式，用以匹配一个单词（\b=单词边界）
  String patt = "\\bfavor\\b";
  // 用于测试的输入字符串
  String input = "Do me a favor? Fetch my favorites.AAA favor BBB";
  System.out.println("Input:" + input);
  // 从正则表达式实例中运行方法并查看其如何运行
  Pattern r = Pattern.compile(patt);
  Matcher m = r.matcher(input);
  System.out.println("ReplaceAll:" + m.replaceAll("favour"));
  // appendReplacement方法
  m.reset();
  StringBuffer sb = new StringBuffer();
  while (m.find()) {
   // 将匹配之前的字符串复制到sb,再将匹配结果替换为："favour"，并追加到sb
   m.appendReplacement(sb, "favour");
  }
  System.out.println(sb.toString());
  m.appendTail(sb);
  System.out.println(sb.toString());
/*
输出：

Input:Do me a favor? Fetch my favorites.AAA favor BBB
ReplaceAll:Do me a favour? Fetch my favorites.AAA favour BBB
Do me a favour? Fetch my favorites.AAA favour
Do me a favour? Fetch my favorites.AAA favour BBB
*/
 }
}