问题
I have a cucumber and selenium test which has always worked fine and suddenly stops running with the below error.
1 Scenarios (1 failed)
14 Steps (14 skipped)
0m0.004s
java.lang.ExceptionInInitializerError
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
at org.picocontainer.injectors.AbstractInjector.newInstance(AbstractInjector.java:145)
at org.picocontainer.injectors.ConstructorInjector$1.run(ConstructorInjector.java:342)
at org.picocontainer.injectors.AbstractInjector$ThreadLocalCyclicDependencyGuard.observe(AbstractInjector.java:270)
at org.picocontainer.injectors.ConstructorInjector.getComponentInstance(ConstructorInjector.java:364)
at org.picocontainer.injectors.AbstractInjectionFactory$LifecycleAdapter.getComponentInstance(AbstractInjectionFactory.java:56)
at org.picocontainer.behaviors.AbstractBehavior.getComponentInstance(AbstractBehavior.java:64)
at org.picocontainer.behaviors.Stored.getComponentInstance(Stored.java:91)
at org.picocontainer.DefaultPicoContainer.getInstance(DefaultPicoContainer.java:699)
at org.picocontainer.DefaultPicoContainer.getComponent(DefaultPicoContainer.java:647)
at org.picocontainer.DefaultPicoContainer.getComponent(DefaultPicoContainer.java:678)
at cucumber.runtime.java.picocontainer.PicoFactory.getInstance(PicoFactory.java:40)
at cucumber.runtime.java.JavaHookDefinition.execute(JavaHookDefinition.java:60)
at cucumber.runtime.Runtime.runHookIfTagsMatch(Runtime.java:224)
at cucumber.runtime.Runtime.runHooks(Runtime.java:212)
at cucumber.runtime.Runtime.runBeforeHooks(Runtime.java:202)
at cucumber.runtime.model.CucumberScenario.run(CucumberScenario.java:40)
at cucumber.runtime.model.CucumberFeature.run(CucumberFeature.java:165)
at cucumber.runtime.Runtime.run(Runtime.java:122)
at cucumber.api.cli.Main.run(Main.java:36)
at cucumber.api.cli.Main.main(Main.java:18)
Caused by: java.lang.NullPointerException
at com.optal.browsers.WebDriverFactory.createAndSetUpThreadedBrowser(WebDriverFactory.java:56)
at com.optal.browsers.WebDriverFactory.create(WebDriverFactory.java:37)
at com.optal.hooks.ScenarioHooks.<clinit>(ScenarioHooks.java:19)
... 24 more
java.lang.NoClassDefFoundError: Could not initialize class com.optal.hooks.ScenarioHooks
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
at org.picocontainer.injectors.AbstractInjector.newInstance(AbstractInjector.java:145)
at org.picocontainer.injectors.ConstructorInjector$1.run(ConstructorInjector.java:342)
at org.picocontainer.injectors.AbstractInjector$ThreadLocalCyclicDependencyGuard.observe(AbstractInjector.java:270)
at org.picocontainer.injectors.ConstructorInjector.getComponentInstance(ConstructorInjector.java:364)
at org.picocontainer.injectors.AbstractInjectionFactory$LifecycleAdapter.getComponentInstance(AbstractInjectionFactory.java:56)
at org.picocontainer.behaviors.AbstractBehavior.getComponentInstance(AbstractBehavior.java:64)
at org.picocontainer.behaviors.Stored.getComponentInstance(Stored.java:91)
at org.picocontainer.DefaultPicoContainer.getInstance(DefaultPicoContainer.java:699)
at org.picocontainer.DefaultPicoContainer.getComponent(DefaultPicoContainer.java:647)
at org.picocontainer.DefaultPicoContainer.getComponent(DefaultPicoContainer.java:678)
at cucumber.runtime.java.picocontainer.PicoFactory.getInstance(PicoFactory.java:40)
at cucumber.runtime.java.JavaHookDefinition.execute(JavaHookDefinition.java:60)
at cucumber.runtime.Runtime.runHookIfTagsMatch(Runtime.java:224)
at cucumber.runtime.Runtime.runHooks(Runtime.java:212)
at cucumber.runtime.Runtime.runAfterHooks(Runtime.java:206)
at cucumber.runtime.model.CucumberScenario.run(CucumberScenario.java:46)
at cucumber.runtime.model.CucumberFeature.run(CucumberFeature.java:165)
at cucumber.runtime.Runtime.run(Runtime.java:122)
at cucumber.api.cli.Main.run(Main.java:36)
at cucumber.api.cli.Main.main(Main.java:18)
Calling System.exit() ..................
Process finished with exit code 1
回答1:
ExceptionInInitializerError
An ExceptionInInitializerError is thrown to indicate that an exception occurred during evaluation of a static initializer or the initializer for a static variable.
The ExceptionInInitializerError is thrown when the JVM attempts to load a new class. During the class loading procedure, all static variables and static initializers are being evaluated. A static initializer is a block enclosed within curly braces without having any name and return type, except having the keyword static.
An example of a static initializer:
import java.util.UUID;
class Example {
private static String ID = null;
static {
ID = UUID.randomUUID().toString();
}
}
The static initializer is evaluated only once during the class loading procedure. Thus, a thrown exception in the evaluation of a static variable or initializer is wrapped into an ExceptionInInitializerError, in order for the JVM to indicate that the class could not be initialized and loaded.
An example that throws ExceptionInInitializerError error is as follows:
public class Example {
private static String message = null;
private static String subMessage = null;
public Example(String message) {
Example.message = message;
}
static {
/* Store the first 10 characters of the input message. */
subMessage = message.substring(0, 10);
}
public String getSubMessage() {
return subMessage;
}
public static void main(String[] args) {
Example exampleClass = new Example("Test");
System.out.println(exampleClass.getSubMessage());
}
}
Executing the above code snippet you will see the following error:
Exception in thread "main" java.lang.ExceptionInInitializerError
Caused by: java.lang.NullPointerException
at main.java.Example.<clinit>(Example.java:13)
You can use either of the following methods to extract more information about the underlying actual exception:
getException(): Returns the exception that occurred during a static initialization that caused this error to be created.getCause(): Returns the exception that caused this error to be thrown.
Dealing with ExceptionInInitializerError
The ExceptionInInitializerError is used as a wrapper to indicate that an exception arises in the static initializer block or the evaluation of a static variable’s value. Thus, we have to ensure that the original exception is fixed, in order for the JVM to be able to load our class successfully.
Outro
You can throw unchecked / runtime exceptions from the block of a static initializer. However, you cannot allow a checked exception to propagate out of a static block, because is not possible to handle these exceptions in your source.
来源：https://stackoverflow.com/questions/55950121/i-am-getting-java-lang-exceptionininitializererror-and-java-lang-noclassdeffound