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
我需要做一个通用的toString(Object obj)帮助类函数，在那里我必须将字段名转换为方法名-传递对象的getXXX()。
下面是代码
/**
* @author DPARASOU
* Utility method to replace the first char of a string with uppercase but leave other chars as it is.
* ToString()
* @param inStr - String
* @return String
*/
public static String firstCaps(String inStr)
{
if (inStr != null && inStr.length() > 0)
{
char[] outStr = inStr.toCharArray();
outStr[0] = Character.toUpperCase(outStr[0]);
return String.valueOf(outStr);
}
else
return inStr;
}
我的toString()实用程序是这样的
public static String getToString(Object obj)
{
StringBuilder toString = new StringBuilder();
toString.append(obj.getClass().getSimpleName());
toString.append("[");
for(Field f : obj.getClass().getDeclaredFields())
{
toString.append(f.getName());
toString.append("=");
try{
//toString.append(f.get(obj)); //access privilege issue
toString.append(invokeGetter(obj, firstCaps(f.getName()), "get"));
}
catch(Exception e)
{
e.printStackTrace();
}
toString.append(", ");
}
toString.setCharAt(toString.length()-2, ']');
return toString.toString();
}
其他回答
最基本和最简单的理解方法(我认为):
import java.util.Scanner;
public class ToUpperCase {
static Scanner kb = new Scanner(System.in);
public static String capitalize(String str){
/* Changes 1st letter of every word
in a string to upper case
*/
String[] ss = str.split(" ");
StringBuilder[] sb = new StringBuilder[ss.length];
StringBuilder capped = new StringBuilder("");
str = "";
// Capitalise letters
for (int i = 0; i < ss.length; i++){
sb[i] = new StringBuilder(ss[i]); // Construct and assign
str += Character.toUpperCase(ss[i].charAt(0)); // Only caps
//======================================================//
// Replace 1st letters with cap letters
sb[i].setCharAt(0, str.charAt(i));
capped.append(sb[i].toString() + " "); // Formatting
}
return capped.toString();
}
public static void main(String[] args){
System.out.println(capitalize(kb.nextLine()));
}
}
Use:
String text = "jon skeet, miles o'brien, old mcdonald";
Pattern pattern = Pattern.compile("\\b([a-z])([\\w]*)");
Matcher matcher = pattern.matcher(text);
StringBuffer buffer = new StringBuffer();
while (matcher.find()) {
matcher.appendReplacement(buffer, matcher.group(1).toUpperCase() + matcher.group(2));
}
String capitalized = matcher.appendTail(buffer).toString();
System.out.println(capitalized);
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
System.out.println("Enter the sentence : ");
try
{
String str = br.readLine();
char[] str1 = new char[str.length()];
for(int i=0; i<str.length(); i++)
{
str1[i] = Character.toLowerCase(str.charAt(i));
}
str1[0] = Character.toUpperCase(str1[0]);
for(int i=0;i<str.length();i++)
{
if(str1[i] == ' ')
{
str1[i+1] = Character.toUpperCase(str1[i+1]);
}
System.out.print(str1[i]);
}
}
catch(Exception e)
{
System.err.println("Error: " + e.getMessage());
}
对于那些在MVC中使用Velocity的人，你可以使用StringUtils类中的capitalizeFirstLetter()方法。
来自Java 9+
你可以像这样使用String::replaceAll:
public static void upperCaseAllFirstCharacter(String text) {
String regex = "\\b(.)(.*?)\\b";
String result = Pattern.compile(regex).matcher(text).replaceAll(
matche -> matche.group(1).toUpperCase() + matche.group(2)
);
System.out.println(result);
}
例子:
upperCaseAllFirstCharacter("hello this is Just a test");
输出
Hello This Is Just A Test
