Java中是否内置了一个函数，使字符串中每个单词的第一个字符大写，而不影响其他字符?
例子:
乔恩·斯基特->乔恩·斯基特 miles o'Brien -> miles o'Brien (B仍然是大写，这排除了Title Case) 老麦当劳->
*(老麦当劳也会被发现，但我不指望它有那么聪明。)
快速浏览一下Java字符串文档就会发现只有toUpperCase()和toLowerCase()，它们当然没有提供所需的行为。当然，谷歌的结果主要是这两个函数。它看起来像一个已经被发明出来的轮子，所以问一下也无妨，这样我以后就可以用它了。
当前回答
这是另一种表达方式:
private String capitalize(String line)
{
StringTokenizer token =new StringTokenizer(line);
String CapLine="";
while(token.hasMoreTokens())
{
String tok = token.nextToken().toString();
CapLine += Character.toUpperCase(tok.charAt(0))+ tok.substring(1)+" ";
}
return CapLine.substring(0,CapLine.length()-1);
}
其他回答
我使用下面的函数。我认为它在性能上更快。
public static String capitalize(String text){
String c = (text != null)? text.trim() : "";
String[] words = c.split(" ");
String result = "";
for(String w : words){
result += (w.length() > 1? w.substring(0, 1).toUpperCase(Locale.US) + w.substring(1, w.length()).toLowerCase(Locale.US) : w) + " ";
}
return result.trim();
}
有很多方法可以转换第一个大写单词的第一个字母。我有个主意。这很简单:
public String capitalize(String str){
/* The first thing we do is remove whitespace from string */
String c = str.replaceAll("\\s+", " ");
String s = c.trim();
String l = "";
for(int i = 0; i < s.length(); i++){
if(i == 0){ /* Uppercase the first letter in strings */
l += s.toUpperCase().charAt(i);
i++; /* To i = i + 1 because we don't need to add
value i = 0 into string l */
}
l += s.charAt(i);
if(s.charAt(i) == 32){ /* If we meet whitespace (32 in ASCII Code is whitespace) */
l += s.toUpperCase().charAt(i+1); /* Uppercase the letter after whitespace */
i++; /* Yo i = i + 1 because we don't need to add
value whitespace into string l */
}
}
return l;
}
如果你需要大写标题，这可能很有用。它将每个由" "分隔的子字符串大写，除了"a"或"the"之类的指定字符串。我还没有运行它，因为已经晚了，不过应该没问题。一次使用Apache Commons StringUtils.join()。如果你愿意，你可以用一个简单的循环来代替它。
private static String capitalize(String string) {
if (string == null) return null;
String[] wordArray = string.split(" "); // Split string to analyze word by word.
int i = 0;
lowercase:
for (String word : wordArray) {
if (word != wordArray[0]) { // First word always in capital
String [] lowercaseWords = {"a", "an", "as", "and", "although", "at", "because", "but", "by", "for", "in", "nor", "of", "on", "or", "so", "the", "to", "up", "yet"};
for (String word2 : lowercaseWords) {
if (word.equals(word2)) {
wordArray[i] = word;
i++;
continue lowercase;
}
}
}
char[] characterArray = word.toCharArray();
characterArray[0] = Character.toTitleCase(characterArray[0]);
wordArray[i] = new String(characterArray);
i++;
}
return StringUtils.join(wordArray, " "); // Re-join string
}
这里是RxJava解决方案的问题
String title = "this is a title";
StringBuilder stringBuilder = new StringBuilder();
Observable.fromArray(title.trim().split("\\s"))
.map(word -> word.substring(0, 1).toUpperCase() + word.substring(1).toLowerCase())
.toList()
.map(wordList -> {
for (String word : wordList) {
stringBuilder.append(word).append(" ");
}
return stringBuilder.toString();
})
.subscribe(result -> System.out.println(result));
不过我还不喜欢for循环。
这是另一种表达方式:
private String capitalize(String line)
{
StringTokenizer token =new StringTokenizer(line);
String CapLine="";
while(token.hasMoreTokens())
{
String tok = token.nextToken().toString();
CapLine += Character.toUpperCase(tok.charAt(0))+ tok.substring(1)+" ";
}
return CapLine.substring(0,CapLine.length()-1);
}
