String s = "姓名是${name},密码是${password}";

Pattern pat = Pattern.compile("\\$\\{[a-zA-Z0-9_-]*\\}");

Matcher mat = pat.matcher(s);

while(mat.find()){

String mm=mat.group(0);

String[] str=mm.split("\\{");

String[] str2=str[1].split("\\}");

System.out.println(str2[0]);

}