我只想通过仅使用Java代码为该问题添加一个替代解决方案。 没有额外的库

public String Capitalize(String str) {

            String tt = "";
            String tempString = "";
            String tempName = str.trim().toLowerCase();
            String[] tempNameArr = tempName.split(" ");
            System.out.println("The size is " + tempNameArr.length);
            if (tempNameArr.length > 1) {
                for (String t : tempNameArr) {
                    tt += Capitalize(t);
                    tt += " ";
                }
                tempString  = tt;
            } else {
                tempString = tempName.replaceFirst(String.valueOf(tempName.charAt(0)), String.valueOf(tempName.charAt(0)).toUpperCase());
            }
            return tempString.trim();
        }

  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);
    }
}

intiCap的可重用方法:

    public class YarlagaddaSireeshTest{

    public static void main(String[] args) {
        String FinalStringIs = "";
        String testNames = "sireesh yarlagadda test";
        String[] name = testNames.split("\\s");

        for(String nameIs :name){
            FinalStringIs += getIntiCapString(nameIs) + ",";
        }
        System.out.println("Final Result "+ FinalStringIs);
    }

    public static String getIntiCapString(String param) {
        if(param != null && param.length()>0){          
            char[] charArray = param.toCharArray(); 
            charArray[0] = Character.toUpperCase(charArray[0]); 
            return new String(charArray); 
        }
        else {
            return "";
        }
    }
}

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());
}

我使用wordUppercase(String s)从雨滴库。 因为这是我的库，这里只有一个方法

 /**
  * Set set first letter from every word uppercase.
  *
  * @param s - The String wich you want to convert.
  * @return The string where is the first letter of every word uppercase.
  */
 public static String wordUppercase(String s){
   String[] words = s.split(" ");
   for (int i = 0; i < words.length; i++) words[i] = words[i].substring(0, 1).toUpperCase() + words[i].substring(1).toLowerCase();
   return String.join(" ", words);
 }

希望能有所帮助。

String s="hi dude i                                 want apple";
    s = s.replaceAll("\\s+"," ");
    String[] split = s.split(" ");
    s="";
    for (int i = 0; i < split.length; i++) {
        split[i]=Character.toUpperCase(split[i].charAt(0))+split[i].substring(1);
        s+=split[i]+" ";
        System.out.println(split[i]);
    }
    System.out.println(s);