问添加新记录时ArrayList记录的错误更新

EN

public static Boolean setProjectNumber(String projectNumberI)
{ // All the 
    if (projectNumberI != projectNumber)
    {
        projectNumber = projectNumberI;
        logAccumulator = logAccumulator + "; project number (" + projectNumberI + ")";
    }
    return true;
}

private static void setLog ()
{ // When all the parameters are set, the log parameter is updated with time tag
    String t = formatterFull.format(GregorianCalendar.getInstance().getTime());
    log = log + "\n" + t + ": " + logAccumulator;       
}

public tasksTableProcessing () 
{ // constructor. Creates the tableRepository object with test records
    tasksRepository.clearDb ();

    taskDef task = null; 
    task = new taskDef ("P1000", "O1", taskStatus.started (), "1", "false", "false");
    tasksRepository.addTask (task);
    System.out.println("\nLog 0: \n" + tasksRepository.getTask(0).getLog());

    task = null;
    task = new taskDef ("P1000", "O1", taskStatus.started(), "2", "false", "true");
    tasksRepository.addTask (task);
    System.out.println("\nLog 1: \n" + tasksRepository.getTask(1).getLog());

    task = null;
    task = new taskDef ("P2000", "O2", "closed", "63", "true", "false");
    tasksRepository.addTask (task);
    System.out.println("\nLog 2: \n" + tasksRepository.getTask(2).getLog());

    task = null;
    task = new taskDef ("P2000", "O2", "closed", "64", "true", "true");
    tasksRepository.addTask (task);
    System.out.println("\nLog 3: \n" + tasksRepository.getTask(3).getLog());
}