public static void main(String[] args) {
    //被替換關鍵字的的數據源
    Map<String,String> tokens = new HashMap<String,String>();
    tokens.put("cat", "Garfield");
    tokens.put("beverage", "coffee");

    //匹配類似velocity規則的字符串
    String template = "${cat} really needs some ${beverage}.";
    //生成匹配模式的正則表達式
    String patternString = "http://$//{(" + StringUtils.join(tokens.keySet(), "|") + ")//}";

    Pattern pattern = Pattern.compile(patternString);
    Matcher matcher = pattern.matcher(template);

    //兩個方法：appendReplacement, appendTail
    StringBuffer sb = new StringBuffer();
    while(matcher.find()) {
        matcher.appendReplacement(sb, tokens.get(matcher.group(1)));
    }
    matcher.appendTail(sb);

    //out: Garfield really needs some coffee.
    System.out.println(sb.toString());

    //對于特殊含義字符"/","$"，使用Matcher.quoteReplacement消除特殊意義
    matcher.reset();
    //out: cat really needs some beverage.
    System.out.println(matcher.replaceAll("$1"));
    //out: $1 really needs some $1.
    System.out.println(matcher.replaceAll(Matcher.quoteReplacement("$1")));

    //到得郵箱的前綴名。插一句，其實驗證郵箱的正則多種多樣，根據自己的需求寫對應的正則才是王道
    String emailPattern = "^([a-z0-9_//.//-//+]+)@([//da-z//.//-]+)//.([a-z//.]{2,6})$";
    pattern = Pattern.compile(emailPattern);
    matcher = pattern.matcher("test@qq.com");
    //驗證是否郵箱
    System.out.println(matcher.find());
    //得到@符號前的郵箱名  out: test
    System.out.println(matcher.replaceAll("$1"));

    //獲得匹配值
    String temp = "<meta-data android:name=/"appid/" android:value=/"joy/"></meta-data>";
    pattern = Pattern.compile("android:(name|value)=/"(.+?)/"");
    matcher = pattern.matcher(temp);
    while(matcher.find()) {
        //out: appid, joy
        System.out.println(matcher.group(2));
    }
}