Question

我的代码出了问题，我似乎无法修复它。我想在提交按钮时将一些客户数据添加到java / GWT中的数组列表中。

我添加数据的表单。

ok.addClickHandler(new ClickHandler() {
        public void onClick(ClickEvent event) {
            if (!voornaamTB.getText().equalsIgnoreCase("") && !achternaamTB.getText().equalsIgnoreCase("") && !emailTB.getText().equalsIgnoreCase("") && !geboortedatumTB.getText().equalsIgnoreCase("")) {
                boolean addVG;
                System.out.println(voornaamTB.getText());
                System.out.println(tussenvoegselTB.getText());
                System.out.println(achternaamTB.getText());
                System.out.println(emailTB.getText());
                System.out.println(geboortedatumTB.getText());
--> the error is generated here addVG = VGC.addVakantieganger(voornaamTB.getText(), tussenvoegselTB.getText(), achternaamTB.getText(), emailTB.getText(), geboortedatumTB.getText());
                if (addVG) {
                    Window.alert("Vakantieganger toegevoegd.");
                } else {
                    Window.alert("Vakantieganger niet toegevoegd.");
                }
            } else {
                voornaamTB.addStyleName("invalide-TextBox");
                tussenvoegselTB.addStyleName("invalide-TextBox");
                achternaamTB.addStyleName("invalide-TextBox");
                emailTB.addStyleName("invalide-TextBox");
                geboortedatumTB.addStyleName("invalide-TextBox");
            }
        }
    });

控制器类。

import java.util.ArrayList;

import com.vakantievibes.client.domein.Vakantieganger;

public class VakantiegangerController {
    private String msg;
    private ArrayList<Vakantieganger> vakantiegangers = new ArrayList<Vakantieganger>();

    public VakantiegangerController(){

    }

@SuppressWarnings("static-access")
public boolean heeftVakantieganger(String email) {
    boolean result = false;
    for (Vakantieganger v : vakantiegangers) {
        if (v.getEmail().equalsIgnoreCase(email)){
            result = true;
        }
    }
    return result;
}

public boolean addVakantieganger(String voornaam, String tussenvoegsel, String achternaam, String email, String geboortedatum) {
    //boolean result = false;

    //if (!heeftVakantieganger(email)) {
        Vakantieganger v = new Vakantieganger(voornaam, tussenvoegsel, achternaam, email, geboortedatum);
        vakantiegangers.add(v);
        boolean result = true;
        System.out.println("klant toegevoegd");
    //}
        return result;
    }

}

使用方法addVakantieganger，它应该将数据添加到arraylist。但它似乎并没有这样做，然后它应该报告真实的形式。！heeftVakantieganger（电子邮件）应该检查这个人是否已经在数组列表中但是现在被禁用用于测试目的

我在日食中收到的错误。

14:17:03.207 [ERROR] [vakantie_vibes] Uncaught exception escaped

com.google.gwt.event.shared.UmbrellaException: One or more exceptions caught, see full set in UmbrellaException#getCauses
    at com.google.gwt.event.shared.HandlerManager.fireEvent(HandlerManager.java:129)
    at com.google.gwt.user.client.ui.Widget.fireEvent(Widget.java:124)
    at com.google.gwt.event.dom.client.DomEvent.fireNativeEvent(DomEvent.java:116)
    at com.google.gwt.user.client.ui.Widget.onBrowserEvent(Widget.java:172)
    at com.google.gwt.user.client.DOM.dispatchEventImpl(DOM.java:1321)
    at com.google.gwt.user.client.DOM.dispatchEvent(DOM.java:1277)
    at sun.reflect.GeneratedMethodAccessor19.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:616)
    at com.google.gwt.dev.shell.MethodAdaptor.invoke(MethodAdaptor.java:103)
    at com.google.gwt.dev.shell.MethodDispatch.invoke(MethodDispatch.java:71)
    at com.google.gwt.dev.shell.OophmSessionHandler.invoke(OophmSessionHandler.java:167)
    at com.google.gwt.dev.shell.BrowserChannelServer.reactToMessagesWhileWaitingForReturn(BrowserChannelServer.java:326)
    at com.google.gwt.dev.shell.BrowserChannelServer.invokeJavascript(BrowserChannelServer.java:207)
    at com.google.gwt.dev.shell.ModuleSpaceOOPHM.doInvoke(ModuleSpaceOOPHM.java:132)
    at com.google.gwt.dev.shell.ModuleSpace.invokeNative(ModuleSpace.java:561)
    at com.google.gwt.dev.shell.ModuleSpace.invokeNativeObject(ModuleSpace.java:269)
    at com.google.gwt.dev.shell.JavaScriptHost.invokeNativeObject(JavaScriptHost.java:91)
    at com.google.gwt.core.client.impl.Impl.apply(Impl.java)
    at com.google.gwt.core.client.impl.Impl.entry0(Impl.java:214)
    at sun.reflect.GeneratedMethodAccessor16.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:616)
    at com.google.gwt.dev.shell.MethodAdaptor.invoke(MethodAdaptor.java:103)
    at com.google.gwt.dev.shell.MethodDispatch.invoke(MethodDispatch.java:71)
    at com.google.gwt.dev.shell.OophmSessionHandler.invoke(OophmSessionHandler.java:167)
    at com.google.gwt.dev.shell.BrowserChannelServer.reactToMessages(BrowserChannelServer.java:281)
    at com.google.gwt.dev.shell.BrowserChannelServer.processConnection(BrowserChannelServer.java:531)
    at com.google.gwt.dev.shell.BrowserChannelServer.run(BrowserChannelServer.java:352)
    at java.lang.Thread.run(Thread.java:679)
Caused by: java.lang.NullPointerException: null
    at com.vakantievibes.client.GUI.FormToevoegenVakantieganger$8.onClick(FormToevoegenVakantieganger.java:153)
    at com.google.gwt.event.dom.client.ClickEvent.dispatch(ClickEvent.java:54)
    at com.google.gwt.event.dom.client.ClickEvent.dispatch(ClickEvent.java:1)
    at com.google.gwt.event.shared.GwtEvent.dispatch(GwtEvent.java:1)
    at com.google.web.bindery.event.shared.SimpleEventBus.doFire(SimpleEventBus.java:193)
    at com.google.web.bindery.event.shared.SimpleEventBus.fireEvent(SimpleEventBus.java:88)
    at com.google.gwt.event.shared.HandlerManager.fireEvent(HandlerManager.java:127)
    at com.google.gwt.user.client.ui.Widget.fireEvent(Widget.java:124)
    at com.google.gwt.event.dom.client.DomEvent.fireNativeEvent(DomEvent.java:116)
    at com.google.gwt.user.client.ui.Widget.onBrowserEvent(Widget.java:172)
    at com.google.gwt.user.client.DOM.dispatchEventImpl(DOM.java:1321)
    at com.google.gwt.user.client.DOM.dispatchEvent(DOM.java:1277)
    at sun.reflect.GeneratedMethodAccessor19.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:616)
    at com.google.gwt.dev.shell.MethodAdaptor.invoke(MethodAdaptor.java:103)
    at com.google.gwt.dev.shell.MethodDispatch.invoke(MethodDispatch.java:71)
    at com.google.gwt.dev.shell.OophmSessionHandler.invoke(OophmSessionHandler.java:167)
    at com.google.gwt.dev.shell.BrowserChannelServer.reactToMessagesWhileWaitingForReturn(BrowserChannelServer.java:326)
    at com.google.gwt.dev.shell.BrowserChannelServer.invokeJavascript(BrowserChannelServer.java:207)
    at com.google.gwt.dev.shell.ModuleSpaceOOPHM.doInvoke(ModuleSpaceOOPHM.java:132)
    at com.google.gwt.dev.shell.ModuleSpace.invokeNative(ModuleSpace.java:561)
    at com.google.gwt.dev.shell.ModuleSpace.invokeNativeObject(ModuleSpace.java:269)
    at com.google.gwt.dev.shell.JavaScriptHost.invokeNativeObject(JavaScriptHost.java:91)
    at com.google.gwt.core.client.impl.Impl.apply(Impl.java)
    at com.google.gwt.core.client.impl.Impl.entry0(Impl.java:214)
    at sun.reflect.GeneratedMethodAccessor16.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:616)
    at com.google.gwt.dev.shell.MethodAdaptor.invoke(MethodAdaptor.java:103)
    at com.google.gwt.dev.shell.MethodDispatch.invoke(MethodDispatch.java:71)
    at com.google.gwt.dev.shell.OophmSessionHandler.invoke(OophmSessionHandler.java:167)
    at com.google.gwt.dev.shell.BrowserChannelServer.reactToMessages(BrowserChannelServer.java:281)
    at com.google.gwt.dev.shell.BrowserChannelServer.processConnection(BrowserChannelServer.java:531)
    at com.google.gwt.dev.shell.BrowserChannelServer.run(BrowserChannelServer.java:352)
    at java.lang.Thread.run(Thread.java:679)

Answer 1

你得到NullPointerException。发生这种情况是因为您使用的引用为null。在您的情况下，这是您标记的行中的一个字段。

使用调试器，在该行上放置断点，并检查null中的哪个字段。

Answer 2

由于您使用了所有变量，目前只有VGC可以是null。

但我怀疑这是一个班级名称。我的第一个猜测是类型VGC是服务器API的一部分，而不是客户端API或类似的东西。

GWT / JAVA Uncaught异常逃脱

2 个答案: