小贝子编程

在JUNit测试中获得NullPointerException



我正试图为大学作业做一些JUnit测试，但每次我试图运行测试时都会出现错误。当我第一次创建我的文件时，它工作得很好，但在我重新启动我的Intellij后，由于一些未知的原因，这开始发生。我创建了这个文件来测试输入的玩家数量。如果该值小于2或大于4，则测试失败。即使在删除失败的测试用例之后，我也会得到错误。我已经尝试重新安装java和javafx，但问题仍然存在。我已经尝试在vscode和智能，但没有运气到目前为止。这是错误:

java.lang.NullPointerException: Cannot invoke "com.sun.glass.ui.Timer.resume()" because "this.pulseTimer" is null
at javafx.graphics@19-ea/com.sun.javafx.tk.quantum.QuantumToolkit.resumeTimer(QuantumToolkit.java:525)
at javafx.graphics@19-ea/com.sun.javafx.tk.quantum.QuantumToolkit$PulseTask.set(QuantumToolkit.java:213)
at javafx.graphics@19-ea/com.sun.javafx.tk.quantum.QuantumToolkit.requestNextPulse(QuantumToolkit.java:887)
at javafx.graphics@19-ea/javafx.scene.Parent.markDirtyLayout(Parent.java:939)
at javafx.graphics@19-ea/javafx.scene.Parent.requestLayout(Parent.java:963)
at javafx.graphics@19-ea/javafx.scene.Scene$8.invalidated(Scene.java:1231)
at javafx.base@19-ea/javafx.beans.property.ObjectPropertyBase.markInvalid(ObjectPropertyBase.java:112)
at javafx.base@19-ea/javafx.beans.property.ObjectPropertyBase.set(ObjectPropertyBase.java:147)
at javafx.graphics@19-ea/javafx.scene.Scene.setRoot(Scene.java:1181)
at javafx.graphics@19-ea/javafx.scene.Scene.<init>(Scene.java:359)
at javafx.graphics@19-ea/javafx.scene.Scene.<init>(Scene.java:239)
at com.cascadia.demo@1.0-SNAPSHOT/com.cascadia.demo.ViewLauncher.<init>(ViewLauncher.java:47)
at com.cascadia.demo@1.0-SNAPSHOT/com.cascadia.demo.ViewLauncherTest.testGetNumPlayer(ViewLauncherTest.java:18)
at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:104)
at java.base/java.lang.reflect.Method.invoke(Method.java:578)
at org.junit.platform.commons.util.ReflectionUtils.invokeMethod(ReflectionUtils.java:725)
at org.junit.jupiter.engine.execution.MethodInvocation.proceed(MethodInvocation.java:60)
at org.junit.jupiter.engine.execution.InvocationInterceptorChain$ValidatingInvocation.proceed(InvocationInterceptorChain.java:131)
at org.junit.jupiter.engine.extension.TimeoutExtension.intercept(TimeoutExtension.java:149)
at org.junit.jupiter.engine.extension.TimeoutExtension.interceptTestableMethod(TimeoutExtension.java:140)
at org.junit.jupiter.engine.extension.TimeoutExtension.interceptTestMethod(TimeoutExtension.java:84)
at org.junit.jupiter.engine.execution.ExecutableInvoker$ReflectiveInterceptorCall.lambda$ofVoidMethod$0(ExecutableInvoker.java:115)
at org.junit.jupiter.engine.execution.ExecutableInvoker.lambda$invoke$0(ExecutableInvoker.java:105)
at org.junit.jupiter.engine.execution.InvocationInterceptorChain$InterceptedInvocation.proceed(InvocationInterceptorChain.java:106)
at org.junit.jupiter.engine.execution.InvocationInterceptorChain.proceed(InvocationInterceptorChain.java:64)
at org.junit.jupiter.engine.execution.InvocationInterceptorChain.chainAndInvoke(InvocationInterceptorChain.java:45)
at org.junit.jupiter.engine.execution.InvocationInterceptorChain.invoke(InvocationInterceptorChain.java:37)
at org.junit.jupiter.engine.execution.ExecutableInvoker.invoke(ExecutableInvoker.java:104)
at org.junit.jupiter.engine.execution.ExecutableInvoker.invoke(ExecutableInvoker.java:98)
at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.lambda$invokeTestMethod$7(TestMethodTestDescriptor.java:214)
at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.invokeTestMethod(TestMethodTestDescriptor.java:210)
at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.execute(TestMethodTestDescriptor.java:135)
at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.execute(TestMethodTestDescriptor.java:66)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$6(NodeTestTask.java:151)
at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$8(NodeTestTask.java:141)
at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:137)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$9(NodeTestTask.java:139)
at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:138)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:95)
at java.base/java.util.ArrayList.forEach(ArrayList.java:1511)
at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.invokeAll(SameThreadHierarchicalTestExecutorService.java:41)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$6(NodeTestTask.java:155)
at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$8(NodeTestTask.java:141)
at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:137)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$9(NodeTestTask.java:139)
at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:138)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:95)
at java.base/java.util.ArrayList.forEach(ArrayList.java:1511)
at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.invokeAll(SameThreadHierarchicalTestExecutorService.java:41)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$6(NodeTestTask.java:155)
at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$8(NodeTestTask.java:141)
at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:137)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$9(NodeTestTask.java:139)
at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:138)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:95)
at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.submit(SameThreadHierarchicalTestExecutorService.java:35)
at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor.execute(HierarchicalTestExecutor.java:57)
at org.junit.platform.engine.support.hierarchical.HierarchicalTestEngine.execute(HierarchicalTestEngine.java:54)
at org.junit.platform.launcher.core.EngineExecutionOrchestrator.execute(EngineExecutionOrchestrator.java:107)
at org.junit.platform.launcher.core.EngineExecutionOrchestrator.execute(EngineExecutionOrchestrator.java:88)
at org.junit.platform.launcher.core.EngineExecutionOrchestrator.lambda$execute$0(EngineExecutionOrchestrator.java:54)
at org.junit.platform.launcher.core.EngineExecutionOrchestrator.withInterceptedStreams(EngineExecutionOrchestrator.java:67)
at org.junit.platform.launcher.core.EngineExecutionOrchestrator.execute(EngineExecutionOrchestrator.java:52)
at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:114)
at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:86)
at org.junit.platform.launcher.core.DefaultLauncherSession$DelegatingLauncher.execute(DefaultLauncherSession.java:86)
at org.junit.platform.launcher.core.SessionPerRequestLauncher.execute(SessionPerRequestLauncher.java:53)
at com.intellij.junit5.JUnit5IdeaTestRunner.startRunnerWithArgs(JUnit5IdeaTestRunner.java:57)
at com.intellij.rt.junit.IdeaTestRunner$Repeater$1.execute(IdeaTestRunner.java:38)
at com.intellij.rt.execution.junit.TestsRepeater.repeat(TestsRepeater.java:11)
at com.intellij.rt.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:35)
at com.intellij.rt.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:232)
at com.intellij.rt.junit.JUnitStarter.main(JUnitStarter.java:55)

JUnit代码是:


import javafx.scene.control.TextField;
import org.junit.jupiter.api.Assertions;
import org.junit.jupiter.api.Test;
public class ViewLauncherTest {
@Test
public void testSetNumPlayer() {
ViewLauncher view = new ViewLauncher();
view.setNum_Player(new TextField("3"));
Assertions.assertEquals(3, view.getNum_Player());
}
@Test
public void testGetNumPlayer() {
ViewLauncher view = new ViewLauncher();
view.setNum_Player(new TextField("4"));
Assertions.assertEquals(4, view.getNum_Player());
}
@Test
public void testInvalidNumPlayer() {
ViewLauncher view = new ViewLauncher();
view.setNum_Player(new TextField("5"));
Assertions.assertThrows(NumberFormatException.class, () -> view.getNum_Player());
}
}

空指针异常不在您的代码中。代码中也没有抛出异常的错误。

问题在于你如何使用API。如果不启动API实现所依赖的JavaFX平台，就不能使用大多数JavaFX API。我看你在测试中没有这么做。Applicationjavadoc解释了JavaFX的生命周期以及如何使用。

需要的是startup在JavaFX平台上，运行一个(或多个)测试，然后exit在所有测试运行后的平台。

如果你想使用junit来测试使用JavaFX的代码，在我看来，最好使用支持它的第三方框架(例如TestFX)。我建议这样做，而不是在您编写的代码中手动管理JavaFX平台状态。

或者，您可以将大部分代码逻辑从JavaFX代码中分离出来(这在任何情况下都是一个好主意)，并使用junit等标准测试工具独立测试非JavaFX逻辑，然后手动测试UI元素。

你的测试和API设计很奇怪。你有:

view.setNum_Player(new TextField("4"));
Assertions.assertEquals(4, view.getNum_Player());

您将玩家数量设置为TextField，但是当您获得玩家数量时，您期望得到一个整数。这说不通啊。如果您在bean上获取和设置一个值，那么它应该按照约定获取和设置相同的值和类型。在您的例子中，它应该是一个整数，而不是一个TextField。

相关内容

最新更新


热门标签：

javascript python java c# php android html jquery c++ css ios sql mysql arrays asp.net json python-3.x ruby-on-rails .net sql-server django objective-c excel regex ruby linux ajax iphone xml vba spring asp.net-mvc database wordpress string postgresql wpf windows xcode bash git oracle list vb.net multithreading eclipse algorithm macos powershell visual-studio image forms numpy scala function api selenium