java - Breaking 2 nested loops "at once"

One approach is to use an exception, depending on the expected result of the db.insert routine.

In short, create a new EDBInsertionException exception (a class extending Exception) and raise the exception in your for loop.

try
{

    while((str=br.readLine())!=null)
    {
        int tempCounter=0;


        for(int i=0;i        {
            String word = str.substring(i, i+3);
            //  System.out.println(word);
            int insert = db.insert(index, word);
            if(insert<0)
            {
                throw new EDBInsertionException("No record inserted: " + insert);
            }

            tempCounter++;
        }
        index++;

        System.out.println("Index Updated: "+index);
        System.out.println(String.valueOf("Total words in this run: "+tempCounter));

        if(index==5)
        {
            break;

        }

    }
}
catch (EDBInsertionException e)
{
    // MZ: The database insertion has failed
    log.error(e.getMessage(), e);

    // MZ: Supplemental action: Delegate, escalate, rollback, etc           

}

EDIT

Expanded the example to illustrate a potential usage of an (user) exception.