Java示例替换首次出现的字符串

import java.util.regex.Matcher;

import java.util.regex.Pattern;



public class Main {

   public static void main(String args[]) {

      Pattern p = Pattern.compile("hello");

      String instring = "hello hello hello.";

      System.out.println("initial String: "+ instring);

      Matcher m = p.matcher(instring);

      String tmp = m.replaceFirst("Java");

      System.out.println("String after replacing 1st Match: " +tmp);

   }

}