java - 如何用后处理值替换正则表达式组？

Question

我有这个代码

public static String ProcessTemplateInput(String input, int count) {
        Pattern pattern = Pattern.compile("\\{([^\\}]+)\\}");
        Matcher matcher = pattern.matcher(input);
        while (matcher.find()) {
            String newelem=SelectRandomFromTemplate(matcher.group(1), count);
        }
        return input;
    }

输入是:

 String s1 = "planets {Sun|Mercury|Venus|Earth|Mars|Jupiter|Saturn|Uranus|Neptune}{?|!|.} Is this ok? ";

输出示例:

String s2="planets Sun, Mercury. Is this ok? ";

我想用该方法返回的选取值替换 {} 组模板。在 Java1.5 中如何做到这一点？

Answer 1

使用appendReplacement/appendTail:

StringBuffer output = new StringBuffer();
while (matcher.find()) {
    matcher.appendReplacement(output, SelectRandomFromTemplate(matcher.group(1), count)); 
}
matcher.appendTail(output);
return output.toString();