Java正则表达式替换的示例

package regex;

import java.util.regex.*;
import java.io.*;

public class Regex {
	
	public static void main(String [] args) {
		String s = "12+3*(2+4)-4*7-1.21";
		Pattern pattern = Pattern.compile("\\d+(\\.\\d+|\\d*)");
		StringBuffer sb = new StringBuffer();
		Matcher matcher = pattern.matcher(s);
		double [] numbers = new double[26];
		int i = -1;
		while (matcher.find()) {
			i++;
			numbers[i] = Double.valueOf(matcher.group());
			matcher.appendReplacement(sb, ""+(char)('A'+i));
		}
		matcher.appendTail(sb);
		System.out.println(sb);
	}
		

}