小编Tra*_*vis的帖子

提前道歉,但我以前从未见过这个错误,也不知道要包括什么.我正在使用NetBeans并突然开始收到此错误:

Exception in thread "AWT-EventQueue-0" java.lang.VerifyError: (class: market/CostOperations, method: <init> signature: ()V) Constructor must call super() or this()
            at Bluebuild.Main.refreshTables(Main.java:748)
            at Bluebuild.Main.formComponentShown(Main.java:649)
            at Bluebuild.Main.access$100(Main.java:28)
            at Bluebuild.Main$2.componentShown(Main.java:374)
            at java.awt.Component.processComponentEvent(Component.java:6095)
            at java.awt.Component.processEvent(Component.java:6043)
            at java.awt.Container.processEvent(Container.java:2041)
            at java.awt.Window.processEvent(Window.java:1836)
            at java.awt.Component.dispatchEventImpl(Component.java:4630)
            at java.awt.Container.dispatchEventImpl(Container.java:2099)
            at java.awt.Window.dispatchEventImpl(Window.java:2478)
            at java.awt.Component.dispatchEvent(Component.java:4460)
            at java.awt.EventQueue.dispatchEvent(EventQueue.java:599)
            at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:269)
            at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:184)
            at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:174)
            at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:169)
            at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:161)
            at java.awt.EventDispatchThread.run(EventDispatchThread.java:122)

我不知道发生了什么.我甚至没有修改market/CostOperations.

这是构造函数:

public CostOperations() throws ParserConfigurationException, SAXException, IOException {

        //Open the xml file
        DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
        DocumentBuilder builder = factory.newDocumentBuilder();
        f = new …

我想要得到几个数字的加权平均值.基本上我有:

Price    - 134.42
Quantity - 15236545

可以有少至一个或两个或多达五十或六十对价格和数量.我需要弄清楚价格的加权平均值.基本上,加权平均值应该给对象提供非常小的权重

Price    - 100000000.00
Quantity - 3

以及更多对上面的那对.

我现在的公式是:

((price)(quantity) + (price)(quantity) + ...)/totalQuantity

到目前为止,我做到了这一点:

        double optimalPrice = 0;
        int totalQuantity = 0;
        double rolling = 0;
        System.out.println(rolling);

        Iterator it = orders.entrySet().iterator();
        while(it.hasNext()) {
            System.out.println("inside");
            Map.Entry order = (Map.Entry)it.next();
            double price = (Double)order.getKey();
            int quantity = (Integer)order.getValue();
            System.out.println(price + " " + quantity);

            rolling += price * quantity;
            totalQuantity += quantity;
            System.out.println(rolling);
        }
        System.out.println(rolling);
        return rolling/totalQuantity;

问题是我很快就将"滚动"变量最大化了.

我怎样才能真正得到加权平均值？