import java.io.*;
public class Upch2
{
   BufferedReader br= new BufferedReader( new InputStreamReader(System.in));
   public void main()throws IOException
    { 
        System.out.println("Pl. Enter A Line");
        String s=br.readLine();
        String s1=" ";
        s=" "+s;
        int len=s.length();
        s= s.toLowerCase();
        for(int j=1;j<len;j++)
         {
           char  ch=s.charAt(j);

           if(s.charAt(j-1)!=' ')
           {
             ch=Character.toLowerCase((s.charAt(j)));
           }
           else
           {
             ch=Character.toUpperCase((s.charAt(j)));
            }
            s1=s1+ch;
          }
     System.out.println(" "+s1);
  }
}

  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);
    }
}

public void capitaliseFirstLetterOfEachWord()
{
    String value="this will capitalise first character of each word of this string";
    String[] wordSplit=value.split(" ");
    StringBuilder sb=new StringBuilder();

    for (int i=0;i<wordSplit.length;i++){

        sb.append(wordSplit[i].substring(0,1).toUpperCase().
                concat(wordSplit[i].substring(1)).concat(" "));
    }
    System.out.println(sb);
}

worddutil .capitalize(str) (from apache common -text)

(注意:如果你需要“fOO BAr”变成“fOO BAr”，那么用大写的(..)代替)

如果你只担心第一个单词的首字母大写:

private String capitalize(final String line) {
   return Character.toUpperCase(line.charAt(0)) + line.substring(1);
}

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);