Question

I was working on a Java web application, and had the following requirement with respect to looping in my HTML table.

I’ve a nested for loop inside a while loop(both execute the same # of times, for ex. say 3).

My code looks something like this:

<table>
<thead>...</thead>
<tbody>

    if (patcases != null && patcases.size() > 0) {
                Iterator itr1 = patcases.iterator();
                while (itr1.hasNext()) {
                    ..some code here..

                    System.out.println("DA Email from webpage..."+da.getEmail());
                       int rCount = 0;  
       <tr>                
                       for(int i=0;i<passedValues.length; i++){

                         ...some code here..
       </tr>

                       System.out.println("Printed row..." +rCount);
                rCount ++;
} /*closing of for loop */
}/*closing of while loop */
}/* closing of if loop */
</tbody>
</table>

Now, with this type of looping structure, I get the following on my console:

DA Email from webpage…[e-mail]
Printed row…0
Printed row…1
Printed row…2
DA Email from webpage…[e-mail]
Printed row…0
Printed row…1
Printed row…2
DA Email from webpage…[e-mail]
Printed row…0
Printed row…1
Printed row…2

But the type of output I wanted was, something as follows:
DA Email from webpage…[e-mail]
Printed row…0
DA Email from webpage…[e-mail]
Printed row…1
DA Email from webpage…[e-mail]
Printed row…2

How would I go about doing this?
Any help would be greatly appreciated.

Answer 1

It looks like you want parallel iteration.

Simply do something like this:

Iterator<?> iter1 = ...;
Iterator<?> iter2 = ...;             // or: int index = 0;

while (iter1.hasNext() &&
           iter2.hasNext()) {        // or: index < MAX

   Object item1 = iter1.next();
   Object item2 = iter2.next();      // or: index++;

   doSomething(item1, item2);        // or: doSomething(item1, index);

}

// perhaps additional handling if one ran out before the other

Note that if at all possible, so you should use parameterized types instead of raw types (Effective Java 2nd Edition, Item 23: Don’t use raw types in new code).