大概可以完成妳所說的功能
package javati;
import java.util.*;
public class zhuanhuan
{
public static void main (String[] args)
{
String input="" ;
Scanner in=new Scanner(System.in);
System.out.println("請輸入壹個數");
input=in.nextLine();
char []c=input.toCharArray() ;
int a=c.length;
int b=a/3;
for(int i=0;i<c.length-2;i=i+3)
{
b--;
if(c[i]=='1')
System.out.print("one hundred ");
else if(c[i]=='2')
System.out.print("two hundred ");
else if(c[i]=='3')
System.out.print("three hundred ");
else if(c[i]=='4')
System.out.print("four hundred ");
else if(c[i]=='5')
System.out.print("five hundred ");
else if(c[i]=='6')
System.out.print("six hundred ");
else if(c[i]=='7')
System.out.print("seven hundred ");
else if(c[i]=='8')
System.out.print("eight hundred ");
else if(c[i]=='9')
System.out.print("nine hundred ");
else
System.out.print("");
if(c[i+1]=='9')
System.out.print("ninty ");
if(c[i+1]=='8')
System.out.print("eighty ");
if(c[i+1]=='7')
System.out.print("seventy ");
if(c[i+1]=='6')
System.out.print("sixty ");
if(c[i+1]=='5')
System.out.print("fifty ");
if(c[i+1]=='4')
System.out.print("fourty ");
if(c[i+1]=='3')
System.out.print("thirty ");
if(c[i+1]=='2')
System.out.print("twenty ");
if(c[i+1]=='1'&&c[i+2]=='1')
System.out.print("eleven");
if(c[i+1]=='1'&&c[i+2]=='2')
System.out.print("twelve");
if(c[i+1]=='1'&&c[i+2]=='3')
System.out.print("thirteen");
if(c[i+1]=='1'&&c[i+2]=='4')
System.out.print("fourteen");
if(c[i+1]=='1'&&c[i+2]=='5')
System.out.print("fifteen");
if(c[i+1]=='1'&&c[i+2]=='6')
System.out.print("sixteen");
if(c[i+1]=='1'&&c[i+2]=='7')
System.out.print("seventeen");
if(c[i+1]=='1'&&c[i+2]=='8')
System.out.print("eighteen");
if(c[i+1]=='1'&&c[i+2]=='9')
System.out.print("nineteen");
if(c[i+2]=='1')
System.out.print("one ");
else if(c[i+2]=='2')
System.out.print("two ");
else if(c[i+2]=='3')
System.out.print("three ");
else if(c[i+2]=='4')
System.out.print("four ");
else if(c[i+2]=='5')
System.out.print("five ");
else if(c[i+2]=='6')
System.out.print("six ");
else if(c[i+2]=='7')
System.out.print("seven ");
else if(c[i+2]=='8')
System.out.print("eight ");
else if(c[i+2]=='9')
System.out.print("nine ");
else
System.out.print("");
if(b==1)
System.out.print("thousand");
if(b==2)
System.out.print("million");
if(b==3)
System.out.print("billion");
System.out.print(" ") ;
}
}
}