Question

I’ve been working at this for a couple hours now and I feel (I hope) I’m right on the verge of figuring it out. This program reads in a bunch of values from an external file and places them in an array of objects which seems to be working just fine.

The Objects properties are:
Bank Account #
Customer Name
Bank Account Balance

1. I can output them in order of Account # (That’s how their read in from the file, no sorting is necessary)

2. I’ve setup a method from implementing Comparable to sort by Bank Account Balance and it’s working fine.

3. I need a second sort method, to sort by Customer Name.
– The problem I’m having with this is based on the research I’ve done and what I’ve tried I’ve come to the conclusion that the only way to make this work will be to build my own Comparable Objects (sorry if my terminology is skewed.) I’ve attempted this as well multiple times with both Java Doc and some similar questions on SE.

When all is said and done I’m going to throw some Listeners into my checkbox group to allow the user to toggle the different sort methods.

Here’s the chunks i’m working on:

 public class bankAccounts implements Comparable<bankAccounts> {
/* PRIVATE FIELDS HERE, FOLLOWED BY TYPICAL GET AND SET METHODS */

 /*SORTS BY ACCOUNT BALANCE WORKING GREAT*/
 public int compareTo(bankAccounts b)   {
    if (accountBalance < b.accountBalance)
    {
        return -1;
    }
    if (accountBalance > b.accountBalance)  {
        return 1;
    }
    return 0;
}


       /* BEGIN SNIPPET OF MAIN CLASS */


      /*METHOD I CALL FROM MAIN CLASS, SORTS BY BALANCE ^^ AS SEEN ABOVE */
Arrays.sort(retrievedAccounts);
for (int i=0; i<retrievedAccounts.length; i++)  {
    String resultFull = Integer.toString(retrievedAccounts[i].getAccountNumber()) + retrievedAccounts[i].getAccountLastName() + Double.toString(retrievedAccounts[i].getAccountBalance());
        box.append(resultFull + "\n");
}

/* NORMAL METHOD WHICH OUTPUTS IN ORDER OF ACCOUNT NUMBER, NO SORTING HAPPENING HERE */
        for(int x = 0; x < retrievedAccounts.length; ++x)
{
    String resultFull=Integer.toString(retrievedAccounts[x].getAccountNumber()) + retrievedAccounts[x].getAccountLastName() + Double.toString(retrievedAccounts[x].getAccountBalance());
    box.append("\n\n\n" + resultFull + "\n\n");
} 

I’m hoping someone will have some insight towards a next step which might allow me to finish this up. If you have suggestions to take this a completely different direction I’m open to that as well.

Answer 1

This is an idea haven’t tested.

Create a another private method to store compareType

public class bankAccounts implements Comparable<bankAccounts> {

private int compareType = 0; // 0 - compare by balance 1-compare by name

In your compare method

public int compareTo(bankAccounts b)   {
if(this.compareType == 0){
if (accountBalance < b.accountBalance)
{
    return -1;
}
if (accountBalance > b.accountBalance)  {
    return 1;
}
return 0;
}else{
 return customerName.compareTo(b.customerName)
}