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
}

我在Java 8中编写了一个更具可读性的解决方案。

public String firstLetterCapitalWithSingleSpace(final String words) {
    return Stream.of(words.trim().split("\\s"))
    .filter(word -> word.length() > 0)
    .map(word -> word.substring(0, 1).toUpperCase() + word.substring(1))
    .collect(Collectors.joining(" "));
}

这个解决方案的要点可以在这里找到:https://gist.github.com/Hylke1982/166a792313c5e2df9d31

    s.toLowerCase().trim();
    result += Character.toUpperCase(s.charAt(0));
    result += s.substring(1, s.indexOf(" ") + 1);
    s = s.substring(s.indexOf(" ") + 1);

    do {
        if (s.contains(" ")) {
            result += " ";
            result += Character.toUpperCase(s.charAt(0));
            result += s.substring(1, s.indexOf(" "));
            s = s.substring(s.indexOf(" ") + 1);
        } else {
            result += " ";
            result += Character.toUpperCase(s.charAt(0));
            result += s.substring(1);
            break;
        }
    } while (true);
    System.out.println(result);

我做了这个小类，可以用来大写一个句子中的每个单词。如果不是空格，可以更改字符串中的单词分隔符。

package com.ecnews.ecnews_v01.Helpers;

  public class Capitalize {

  String sentence;
  String separator = " ";

  public Capitalize(String sentence) {
    this.sentence = sentence;
  }

  public void setSeparator(String separator) {
    this.separator = separator;
  }

  public String getCapitalized() {
    StringBuilder capitalized = new StringBuilder("");
    for (String word : sentence.split(separator)) {
        capitalized.append(separator+Character.toUpperCase(word.charAt(0)) + word.substring(1));
    }
    return capitalized.toString().trim();
  }

}

例子:

String sourceName = new Capitalize("this is a test"). get资本化();

sourceName将是“This Is A Test”

  package com.test;

 /**
   * @author Prasanth Pillai
   * @date 01-Feb-2012
   * @description : Below is the test class details
   * 
   * inputs a String from a user. Expect the String to contain spaces and    alphanumeric     characters only.
   * capitalizes all first letters of the words in the given String.
   * preserves all other characters (including spaces) in the String.
   * displays the result to the user.
   * 
   * Approach : I have followed a simple approach. However there are many string    utilities available 
   * for the same purpose. Example : WordUtils.capitalize(str) (from apache commons-lang)
   *
   */
  import java.io.BufferedReader;
  import java.io.IOException;
  import java.io.InputStreamReader;

  public class Test {

public static void main(String[] args) throws IOException{
    System.out.println("Input String :\n");
    InputStreamReader converter = new InputStreamReader(System.in);
    BufferedReader in = new BufferedReader(converter);
    String inputString = in.readLine();
    int length = inputString.length();
    StringBuffer newStr = new StringBuffer(0);
    int i = 0;
    int k = 0;
    /* This is a simple approach
     * step 1: scan through the input string
     * step 2: capitalize the first letter of each word in string
     * The integer k, is used as a value to determine whether the 
     * letter is the first letter in each word in the string.
     */

    while( i < length){
        if (Character.isLetter(inputString.charAt(i))){
            if ( k == 0){
            newStr = newStr.append(Character.toUpperCase(inputString.charAt(i)));
            k = 2;
            }//this else loop is to avoid repeatation of the first letter in output string 
            else {
            newStr = newStr.append(inputString.charAt(i));
            }
        } // for the letters which are not first letter, simply append to the output string. 
        else {
            newStr = newStr.append(inputString.charAt(i));
            k=0;
        }
        i+=1;           
    }
    System.out.println("new String ->"+newStr);
    }
}

以下方法将所有字母转换为大写/小写，取决于它们靠近空格或其他特殊字符的位置。

public static String capitalizeString(String string) {
  char[] chars = string.toLowerCase().toCharArray();
  boolean found = false;
  for (int i = 0; i < chars.length; i++) {
    if (!found && Character.isLetter(chars[i])) {
      chars[i] = Character.toUpperCase(chars[i]);
      found = true;
    } else if (Character.isWhitespace(chars[i]) || chars[i]=='.' || chars[i]=='\'') { // You can add other chars here
      found = false;
    }
  }
  return String.valueOf(chars);
}