Library class printing troubles

Question

I am making a library type program with users and books that functions like a library. One of the methods prints all of the loans in the library, this is where i am having trouble
public String printAllLoans() {
* return a String representation of all loans from all patrons in the library system, return nothing if no loans
/*     //Collaborated with Greg
     String printallLoans="";
     String none = "None";
     int index = 0;
     for (; index < this.patronCount(); index++){
          if (((Patron) this.patrons.elementAt(index)).countLoans() > 0)
               printallLoans.concat(((Patron) this.patrons.elementAt(index)).allLoans());
          //System.out.println("* " + ((Patron) this.patrons.elementAt(index)).allLoans() + "*  and length: " + ((Patron) this.patrons.elementAt(index)).allLoans().length());
     if (printallLoans.length() == 0)
          return none;
     else
          return printallLoans;*/
     int index = 0;
     int totalPrinted = 0;
     for (;index < this.patronCount() - 1; index++){
          if (((Patron) this.patrons.elementAt(index)).countLoans() > 0){
               System.out.println(((Patron) this.patrons.elementAt(index)).allLoans());
               totalPrinted++;
     if (totalPrinted >= 0){
          if (((Patron) this.patrons.elementAt(index)).countLoans() > 0)
               return ((Patron) this.patrons.elementAt(this.patronCount() - 1)).allLoans();
          //if (((Patron) this.patrons.elementAt(index)).countLoans() == 0)
          //     return "None";
     //if (((Patron) this.patrons.elementAt(index)).countLoans() == 0 && totalPrinted == 0)
     return "None";
*From the patron class:*
public String allLoans() {
* return a String representation of all my loans in the library system, if no loans, return "None"
* (e.g. Books on loan to patron # 0:
* #: 0 "JAVA STRUCTURES" By: BAILE */
     int amountOnLoan = this.countLoans();
     if (amountOnLoan != 0){
          System.out.println("Books on loan to patron # " + this.patronNumber + ":");
          int bookOnLoan = amountOnLoan;
          while (bookOnLoan > 0){
               System.out.println(((Book) this.booksOnLoan.elementAt(bookOnLoan - 1)).toString());
               bookOnLoan--;
               //System.out.println("Amount on loan: " + amountOnLoan);
     if (amountOnLoan == 0)
          return "None";
     return "";
public int countLoans() {
* return my total number of loans
     return this.booksOnLoan.size();
}When i try to printAllLoans() i want it to cycle through the vector of patrons in the library and if countLoans() > 0 (i.e. their is a book on loan) i want it to print the books that are on loan. But if it cycles through all of the patrons and doesn't find any books on loan i want it to return "None". Right now it will return none when it's not supposed to, here is a sample output.
Patron Menu
+1. Add a new Patron+
+2. Delete a Patron+
+3. Patron Count+
+4. Print Patron Catalog+
+5. Print a Patron's loan+
+6. Print all loans+
+7. Exit+
Please choose an option: 6
Books on loan to patron # 3:
+#3 "ON TO JAVA" By: WINSTON+
None+ <------- This should not be here it should have only printed the book on loan.
Anyone konw where my code is wrong?

Answer 1

The method must return a result of type String, that is set by the profs. I need it to print all of the loans, but i dont know of a way to return only one string that will have all of the loans attached to it. So i figured i would print some of them and return the last one so it can be printed (System.out.print(aCatalog.printAllLoans()). Is their a way i can make an empty string that would just concat all of the loans to itself and if it's length is 0 print none?
Maybe:
String printallLoans="";
     String none = "None";
     int index = 0;
     for (; index < this.patronCount(); index++){
          if (((Patron) this.patrons.elementAt(index)).countLoans() > 0)
               printallLoans.concat(((Patron) this.patrons.elementAt(index)).allLoans());
          //System.out.println("* " + ((Patron) this.patrons.elementAt(index)).allLoans() + "*  and length: " + ((Patron) this.patrons.elementAt(index)).allLoans().length());
     if (printallLoans.length() == 0)
          return none;
     else
          return printallLoans;I tried this and it will always return None, looking at the allLoans method, if the user has no loans it will return "none", so the lenth of printallLoans would be 4, not 0. So i changed
if (printallLoans.length() == 4)
          return none;
     else
          return printallLoans;But this didn't want to work either, sample output:
====List all Loans====
Books on loan to patron # 6:
#0 "CRACKCOCAINE" By: UOFA
====Should read one book====
====List all Loans====
Books on loan to patron # 3:
#1 "IAMABOOK" By: IMANAUTHOR
Books on loan to patron # 6:
#0 "CRACKCOCAINE" By: UOFA
====Should read two books====
====List all Loans - Books were returned====
<-------------NOTHING HERE!!!, should have printed None because both books that were on loan were returned.
====Should read None====
Any ideas?