java 正则扫描EL 表达式

public static void main(String[] args) {

Map map = new HashMap(2);
map.put("name", "Jame Gosling");
map.put("alias", "Rod Johnson");
String line = "${name} did a great job, so ${alias} did.";
String regex = "\\$\\{[^\\}]+\\}";

Pattern p = Pattern.compile(regex);
Matcher m = p.matcher(line);

String g;
while (m.find()) {
g = m.group();
g = g.substring(2, g.length() - 1);
line = m.replaceFirst(map.get(g) + "");
m = p.matcher(line);
}
System.out.println(line);

}