我有一个字符串：“你好旧世界”，我希望每个单词的每个第一个字母大写，而不是整个字符串.toUpperCase（）。是否有现有的java帮助程序来完成这项工作？
答案 0 :(得分：124)
查看ACL WordUtils。
WordUtils.capitalize("your string") == "Your String"
答案 1 :(得分：67)
这是代码
String source = "hello good old world";
StringBuffer res = new StringBuffer();
String[] strArr = source.split(" ");
for (String str : strArr) {
char[] stringArray = str.trim().toCharArray();
stringArray[0] = Character.toUpperCase(stringArray[0]);
str = new String(stringArray);
res.append(str).append(" ");
}
System.out.print("Result: " + res.toString().trim());
答案 2 :(得分：52)
sString = sString.toLowerCase();
sString = Character.toString(sString.charAt(0)).toUpperCase()+sString.substring(1);
答案 3 :(得分：44)
我不知道是否有功能，但如果没有功能，这将完成工作：
String s = "here are a bunch of words";
final StringBuilder result = new StringBuilder(s.length());
String[] words = s.split("\\s");
for(int i=0,l=words.length;i<l;++i) {
if(i>0) result.append(" ");
result.append(Character.toUpperCase(words[i].charAt(0)))
.append(words[i].substring(1));
}
答案 4 :(得分：19)
import org.apache.commons.lang.WordUtils;
public class CapitalizeFirstLetterInString {
public static void main(String[] args) {
// only the first letter of each word is capitalized.
String wordStr = WordUtils.capitalize("this is first WORD capital test.");
//Capitalize method capitalizes only first character of a String
System.out.println("wordStr= " + wordStr);
wordStr = WordUtils.capitalizeFully("this is first WORD capital test.");
// This method capitalizes first character of a String and make rest of the characters lowercase
System.out.println("wordStr = " + wordStr );
}
}
输出：
这是第一次WORD资本测试。
这是第一个字资本测试。
答案 5 :(得分：12)
这是一个非常简单，紧凑的解决方案。 str包含你要做大写的任何变量。
StringBuilder b = new StringBuilder(str);
int i = 0;
do {
b.replace(i, i + 1, b.substring(i,i + 1).toUpperCase());
i = b.indexOf(" ", i) + 1;
} while (i > 0 && i < b.length());
System.out.println(b.toString());
最好使用StringBuilder，因为String是不可变的，并且为每个单词生成新的字符串效率很低。
答案 6 :(得分：11)
尝试提高内存效率，而不是将字符串拆分为多个字符串，并使用Darshana Sri Lanka所示的策略。此外，处理单词之间的所有空格，而不仅仅是“”字符。
public static String UppercaseFirstLetters(String str)
{
boolean prevWasWhiteSp = true;
char[] chars = str.toCharArray();
for (int i = 0; i < chars.length; i++) {
if (Character.isLetter(chars[i])) {
if (prevWasWhiteSp) {
chars[i] = Character.toUpperCase(chars[i]);
}
prevWasWhiteSp = false;
} else {
prevWasWhiteSp = Character.isWhitespace(chars[i]);
}
}
return new String(chars);
}
答案 7 :(得分：7)
String s = "java is an object oriented programming language.";
final StringBuilder result = new StringBuilder(s.length());
String words[] = s.split("\\ "); // space found then split it
for (int i = 0; i < words.length; i++)
{
if (i > 0){
result.append(" ");
}
result.append(Character.toUpperCase(words[i].charAt(0))).append(
words[i].substring(1));
}
System.out.println(result);
输出： Java是一种面向对象的编程语言。
答案 8 :(得分：4)
您也可以查看StringUtils库。它有很多很酷的东西。
答案 9 :(得分：2)
import java.util.Scanner;
public class CapitolizeOneString {
public static void main(String[] args)
{
Scanner scan = new Scanner(System.in);
System.out.print(" Please enter Your word = ");
String str=scan.nextLine();
printCapitalized( str );
} // end main()
static void printCapitalized( String str ) {
// Print a copy of str to standard output, with the
// first letter of each word in upper case.
char ch; // One of the characters in str.
char prevCh; // The character that comes before ch in the string.
int i; // A position in str, from 0 to str.length()-1.
prevCh = '.'; // Prime the loop with any non-letter character.
for ( i = 0; i < str.length(); i++ ) {
ch = str.charAt(i);
if ( Character.isLetter(ch) && ! Character.isLetter(prevCh) )
System.out.print( Character.toUpperCase(ch) );
else
System.out.print( ch );
prevCh = ch; // prevCh for next iteration is ch.
}
System.out.println();
}
} // end class
答案 10 :(得分：2)
public class WordChangeInCapital{
public static void main(String[] args)
{
String s="this is string example";
System.out.println(s);
//this is input data.
//this example for a string where each word must be started in capital letter
StringBuffer sb=new StringBuffer(s);
int i=0;
do{
b.replace(i,i+1,sb.substring(i,i+1).toUpperCase());
i=b.indexOf(" ",i)+1;
} while(i>0 && i<sb.length());
System.out.println(sb.length());
}
}
答案 11 :(得分：2)
package com.raj.samplestring;
/**
* @author gnagara
*/
public class SampleString {
/**
* @param args
*/
public static void main(String[] args) {
String[] stringArray;
String givenString = "ramu is Arr Good boy";
stringArray = givenString.split(" ");
for(int i=0; i<stringArray.length;i++){
if(!Character.isUpperCase(stringArray[i].charAt(0))){
Character c = stringArray[i].charAt(0);
Character change = Character.toUpperCase(c);
StringBuffer ss = new StringBuffer(stringArray[i]);
ss.insert(0, change);
ss.deleteCharAt(1);
stringArray[i]= ss.toString();
}
}
for(String e:stringArray){
System.out.println(e);
}
}
}
答案 12 :(得分：2)
这是一个简单的解决方案：
public class CapitalFirstLetters {
public static void main(String[] args) {
String word = "it's java, baby!";
String[] wordSplit;
String wordCapital = "";
wordSplit = word.split(" ");
for (int i = 0; i < wordSplit.length; i++) {
wordCapital = wordSplit[i].substring(0, 1).toUpperCase() + wordSplit[i].substring(1) + " ";
}
System.out.println(wordCapital);
}}
答案 13 :(得分：2)
在阅读上述几个答案之后我的代码。
/**
* Returns the given underscored_word_group as a Human Readable Word Group.
* (Underscores are replaced by spaces and capitalized following words.)
*
* @param pWord
* String to be made more readable
* @return Human-readable string
*/
public static String humanize2(String pWord)
{
StringBuilder sb = new StringBuilder();
String[] words = pWord.replaceAll("_", " ").split("\\s");
for (int i = 0; i < words.length; i++)
{
if (i > 0)
sb.append(" ");
if (words[i].length() > 0)
{
sb.append(Character.toUpperCase(words[i].charAt(0)));
if (words[i].length() > 1)
{
sb.append(words[i].substring(1));
}
}
}
return sb.toString();
}
答案 14 :(得分：1)
public String UpperCaseWords(String line)
{
line = line.trim().toLowerCase();
String data[] = line.split("\\s");
line = "";
for(int i =0;i< data.length;i++)
{
if(data[i].length()>1)
line = line + data[i].substring(0,1).toUpperCase()+data[i].substring(1)+" ";
else
line = line + data[i].toUpperCase();
}
return line.trim();
}
答案 15 :(得分：1)
正则表达式简单得多：
Pattern spaces=Pattern.compile("\\s+[a-z]");
Matcher m=spaces.matcher(word);
StringBuilder capitalWordBuilder=new StringBuilder(word.substring(0,1).toUpperCase());
int prevStart=1;
while(m.find()) {
capitalWordBuilder.append(word.substring(prevStart,m.end()-1));
capitalWordBuilder.append(word.substring(m.end()-1,m.end()).toUpperCase());
prevStart=m.end();
}
capitalWordBuilder.append(word.substring(prevStart,word.length()));
输入输出：“这句话有奇怪的上限”
这句话有奇怪的上限