给出一个像这样的字符串：
Hello {FIRST_NAME},this is a personalized message for you.
其中FIRST_NAME是任意令牌(传递给方法的地图中的一个键),要编写一个将该字符串变为：
Hello Jim,this is a personalized message for you.
给出了一个带有条目FIRST_NAME的地图 – >吉姆.
看起来StringTokenizer是最直接的方法,但Javadocs真的说你应该更喜欢使用正则表达式.您将如何在基于正则表达式的解决方案中执行此操作？
解决方法
尝试这个：
注意：author’s final solution建立在这个样本之上,更简洁.
public class TokenReplacer {
private Pattern tokenPattern;
public TokenReplacer() {
tokenPattern = Pattern.compile("\\{([^}]+)\\}");
}
public String replaceTokens(String text,Map<String,String> valuesByKey) {
StringBuilder output = new StringBuilder();
Matcher tokenMatcher = tokenPattern.matcher(text);
int cursor = 0;
while (tokenMatcher.find()) {
// A token is defined as a sequence of the format "{...}".
// A key is defined as the content between the brackets.
int tokenStart = tokenMatcher.start();
int tokenEnd = tokenMatcher.end();
int keyStart = tokenMatcher.start(1);
int keyEnd = tokenMatcher.end(1);
output.append(text.substring(cursor,tokenStart));
String token = text.substring(tokenStart,tokenEnd);
String key = text.substring(keyStart,keyEnd);
if (valuesByKey.containsKey(key)) {
String value = valuesByKey.get(key);
output.append(value);
} else {
output.append(token);
}
cursor = tokenEnd;
}
output.append(text.substring(cursor));
return output.toString();
}
}
