Here is my first attempt..let me know if this is what you were looking for
import java.util.List;
import java.util.ArrayList;
public class EncryptName {
public EncryptName() {
}
public EncryptName(String[] args) {
char[] custChars = {'a','b','c','d'};
for(int n=0;n<args.length;n++){
//validate each entry from array
char[] arr = validateName(args[n]);//makes sure name is>=4 chars and
//return the first 4 chars
if(arr!=null){
arr = formatName(arr,custChars);
char[] tarr=new char[arr.length];
for(int x=arr.length-1;x>=0;x--){
tarr[((arr.length-1)-x)] = arr[x];
}
String codeStr = "",userName="";
for(int x=0;x<tarr.length;x++){
codeStr += tarr[x] * 3;
userName+= tarr[x];
}
System.out.println("userName ["+userName+"]"+
"\nCoded string ["+codeStr+"]");
}else{
System.out.println("Either name is less then 4 characters or wrong format");
}
}
}
private char[] validateName(String name){
char[] arr=new char[4];
if(name.length()>=4){
for(int n=0;n<name.length();n++){
if(n<4){
arr[n] = name.charAt(n);
}
}
}
return arr;
}
private char[] formatName(char[] arr,char[] custChars){
char[] narr = new char[7];
int n1=0,n2=0,n=0;
while(n<narr.length){
narr[n++] = arr[n1++];
if(n<narr.length-1){
narr[n++] = custChars[n2++];
}
}
return narr;
}
public static void main(String[] args) {
if(args!=null & args.length>0){
EncryptName encryptName1 = new EncryptName(args);
}else{
System.out.println("HELP : please follow the pattern below to run this program\n\n"+
"EncryptName <parameter>\nWhere you can enter multiple paramters\n"+
"A paramter should be in the alphanumeric string");
}
}
}