Java Swing中的线程获取令人惊讶的异常

Question

I am getting the following amazing exception when I am using multi-threading in my code but, I can not figure out where it occurs. Also this exception occurs only sometimes.

Exception in thread "AWT-EventQueue-0" java.util.NoSuchElementException: Vector Enumeration at java.util.Vector$1.nextElement(Vector.java:348) at javax.swing.plaf.basic.BasicTableHeaderUI.getPreferredSize(BasicTableHeaderUI.java:793) at javax.swing.JComponent.getPreferredSize(JComponent.java:1660)

I am using the below code for multi-threading in my application.

       try {
        Thread Thread4 = new Thread() {
           public void run() {
                GetOrderData(mID, "OrderInfo_Orn");
            }
        };
        Thread4.start();
        Thread4.sleep(20);

        Thread Thread5 = new Thread() {
           public void run() {
                GetOrderData(mID, "OrderInfo_Parts");
            }
        };
        Thread5.start();
        Thread5.sleep(20);
        Thread queryThread = new Thread() {

            public void run() {
                GetMasterData(mID, rowId);
            }
        };
        queryThread.start();
        queryThread.sleep(20);
        Thread Thread2 = new Thread() {
            public void run() {
                GetDetailData(mID, "'RcvPrePolishGoods_Detail'");
            }
        };
        Thread2.start();
        Thread2.sleep(20);

        Thread Thread3 = new Thread() {
            public void run() {
                GetDetailData(mID, "'RcvPrePolishGoods_Parts'");
            }
        };
        Thread3.start();
        Thread3.sleep(20);
      } catch (InterruptedException ex) {
        Logger.getLogger(RcvPrePolishGoods.class.getName()).log(Level.SEVERE, null, ex);
    }

Answer 1

Theres a couple things you want to look into:

1. If your updating the GUI (adding items to a JTable is what the exception implies) from the Get****Data functions, you're going to run into EDT problems (that's the AWT-EventQueue-0 you see in the error). Instead use SwingUtils.InvokeLater() . Or if you need it to run after 20 ms (or at 20 ms intervals), use a Swing Timer

2. You're calling threadname.start(); and then in the next line, calling threadname.sleep(20); . According to the API , Thread.sleep causes the currently running thread to wait - which in this case is the EDT (not threadname). If you want threadname to sleep, place the sleep inside the runnable like this:

    Thread Thread5 = new Thread() { public void run() { Thread.sleep(); GetOrderData(mID, "OrderInfo_Parts"); } };