Thread: bound mismatcherror?

public class Tester
{
 
public static void main(String[]args)
{
 
ArrayList<BankAccount> balance = new ArrayList<BankAccount>();
 
 
balance.add(new BankAccount(1000));
balance.add(new BankAccount(1500));
balance.add(new BankAccount(750));
balance.add(new BankAccount(2350));
balance.add(new BankAccount(525));
 
Collections.sort(balance); // this is the error line
}
 
 
 
public interface Comparable <BankAccount>
{
 
int compareTo(Object other);
 
}

public class BankAccount implements Comparable <BankAccount>
{
..... etc
}

Can anyone tell me what the problem is?

Description
Bound mismatch: The generic method sort(List<T>) of type Collections is not applicable for the arguments (ArrayList<BankAccount>). The inferred type BankAccount is not a valid substitute for the bounded parameter <T extends Comparable<? super T>>line 44 Java Problem

Thanks.

1. You should reread the Generics section of the java tutorials. Generics can get complex, and it doesn't hurt to read this section many times to ensure you understand them and are using them correctly.

2. The sort method of Collections has this signature "public static <T extends Comparable<? super T>> void sort(List<T> list)"

Since it looks like you are declaring your own interface named Comparable (instead of using java.lang.Comparable) you are not satisfying these requirements. Get rid of the interface you created, and use the Comparable interface that is part of the java.lang. package

Thanks you, it helped me solve my problem.