? ? ? ? 做了一段時(shí)間的jdk８項(xiàng)目后崎场，jdk９發(fā)布了佩耳，跟隨時(shí)代的潮流，立馬將jdk切換為９谭跨，然后干厚。李滴。。蛮瞄。所坯。」彝保　　運(yùn)行什么的都沒有問題芹助，在進(jìn)行mvn clean install后，吧啦吧啦的一大堆test error闲先，單獨(dú)運(yùn)行一個(gè)子項(xiàng)目后發(fā)現(xiàn)状土，運(yùn)行測(cè)試用例的時(shí)候程序拋異常了：

java.lang.IllegalStateException: Failed to load ApplicationContext at org.springframework.test.context.cache.DefaultCacheAwareContextLoaderDelegate.loadContext(DefaultCacheAwareContextLoaderDelegate.java:124)at org.springframework.test.context.support.DefaultTestContext.getApplicationContext(DefaultTestContext.java:83)at org.springframework.test.context.support.DependencyInjectionTestExecutionListener.injectDependencies(DependencyInjectionTestExecutionListener.java:117)at org.springframework.test.context.support.DependencyInjectionTestExecutionListener.prepareTestInstance(DependencyInjectionTestExecutionListener.java:83)at org.springframework.boot.test.autoconfigure.SpringBootDependencyInjectionTestExecutionListener.prepareTestInstance(SpringBootDependencyInjectionTestExecutionListener.java:44)at org.springframework.test.context.TestContextManager.prepareTestInstance(TestContextManager.java:230)at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.createTest(SpringJUnit4ClassRunner.java:228)at org.springframework.test.context.junit4.SpringJUnit4ClassRunner$1.runReflectiveCall(SpringJUnit4ClassRunner.java:287)at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.methodBlock(SpringJUnit4ClassRunner.java:289)at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:247)at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:94)at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)at org.springframework.test.context.junit4.statements.RunBeforeTestClassCallbacks.evaluate(RunBeforeTestClassCallbacks.java:61)at org.springframework.test.context.junit4.statements.RunAfterTestClassCallbacks.evaluate(RunAfterTestClassCallbacks.java:70)at org.junit.runners.ParentRunner.run(ParentRunner.java:363)at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.run(SpringJUnit4ClassRunner.java:191)at org.junit.runner.JUnitCore.run(JUnitCore.java:137)at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68)at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:47)at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:242)at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:70)`Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'entityManagerFactory' defined in class path resource [org/springframework/boot/autoconfigure/orm/jpa/HibernateJpaAutoConfiguration.class]: Invocation of init method failed; nested exception is java.lang.NoClassDefFoundError: javax/xml/bind/JAXBException`at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1628)at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:555)at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:483)at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306)at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230)at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302)at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197)at org.springframework.context.support.AbstractApplicationContext.getBean(AbstractApplicationContext.java:1078)at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:857)at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:543)at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:693)at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:360)at org.springframework.boot.SpringApplication.run(SpringApplication.java:303)at org.springframework.boot.test.context.SpringBootContextLoader.loadContext(SpringBootContextLoader.java:120)at org.springframework.test.context.cache.DefaultCacheAwareContextLoaderDelegate.loadContextInternal(DefaultCacheAwareContextLoaderDelegate.java:98)at org.springframework.test.context.cache.DefaultCacheAwareContextLoaderDelegate.loadContext(DefaultCacheAwareContextLoaderDelegate.java:116)... 25 more`Caused by: java.lang.NoClassDefFoundError: javax/xml/bind/JAXBException`at org.hibernate.boot.spi.XmlMappingBinderAccess.(XmlMappingBinderAccess.java:43)at org.hibernate.boot.MetadataSources.(MetadataSources.java:87)at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.(EntityManagerFactoryBuilderImpl.java:179)at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.(EntityManagerFactoryBuilderImpl.java:149)at org.springframework.orm.jpa.vendor.SpringHibernateJpaPersistenceProvider.createContainerEntityManagerFactory(SpringHibernateJpaPersistenceProvider.java:54)at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.createNativeEntityManagerFactory(LocalContainerEntityManagerFactoryBean.java:353)at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.buildNativeEntityManagerFactory(AbstractEntityManagerFactoryBean.java:370)at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.afterPropertiesSet(AbstractEntityManagerFactoryBean.java:359)at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1687)at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1624)... 40 more`Caused by: java.lang.ClassNotFoundException: javax.xml.bind.JAXBException`at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:582)at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:185)at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:496)... 50 more

? ? ? 直接繞過百度、必應(yīng)伺糠，在ｇｏｏｇｌｅ上一搜蒙谓，情況立馬知曉了。ｓｔａｃｋｏｖｅｒｆｌｏｗ上面這么解釋： The JAXB APIs are considered to be Java EE APIs, and therefore are no longer contained on the default class path in Java SE 9.Java 9 introduces the concepts of modules, and by default the `java.se` aggregate module is available on the class path (or rather, module path).?

As the name implies, the `java.se` aggregate module does _not_ include the Java EE APIs that have been traditionally bundled with Java 6/7/8.Fortunately, these Java EE APIs that were provided in JDK 6/7/8 are still in the JDK, but they just aren't on the class path by default. The extra Java EE APIs are provided in the following modules:```java.activationjava.corbajava.transactionjava.xml.bind << This one contains the JAXB APIsjava.xml.wsjava.xml.ws.annotation```

**Quick Solution:**To make the JAXB APIs available at runtime, specify the following command-line option:`--add-modules java.xml.bind`**But I still need this to work with Java 8!!!**

If you try specifying `--add-modules` with an older JDK, it will blow up becuase it's an unrecognized option. I suggest one of two options:

1. You can conditionally apply the argument in a launch script (if you have one) by inspecting the JDK version by inspecting `$JAVA_HOME/release` for the `JAVA_VERSION` property.

2. You can add the `-XX:+IgnoreUnrecognizedVMOptions` to make the JVM silently ignore unrecongized options, instead of blowing up. But beware! Any other command line args you use will no longer be validated for you by the JVM. This option works with Oracle/OpenJDK as well as IBM JDK (as of JDK 8sr4)?

? ? ? ?怎么樣训桶？看出來什么了么彼乌？簡(jiǎn)單來說，就是ｊｄｋ９的模塊化功能造成的渊迁，`java.xml.bind`其實(shí)是屬于ｊａｖａ∥空铡ｅｅ的模塊，在ｊｄｋ６／７／８版本中都放在了默認(rèn)的ｐａｔｈ下面琉朽，但是到了ｊｄｋ９毒租，就把這些模塊都移出來了，就是沒有放在默認(rèn)的ｐａｔｈ下面箱叁，如果想要使用墅垮，那么你需要在運(yùn)行時(shí)加上ｏｐｔｉｏｎｓ命令`--add-modules java.xml.bind`。

?那么坑又來了耕漱，我一開始的時(shí)候以為是需要通過命令 `java --add-modules java.xml.bind`去添加模塊算色，ｊａｖａ命令中也有這個(gè)命令，但就是提示命令可能有誤螟够，一直沒反應(yīng)灾梦。然后就去把ｇｏｏｇｌｅ各種翻，最終妓笙，結(jié)果找到了：

```Test FailureThe next step sees the failure of unit tests to fail with `mvn test`.The cause is the same, but it’s a bit harder to find. It requires checking the Surefire reports.

?Some contain exceptions with the following line:Caused by: java.lang.ClassNotFoundException: javax.xml.bind.JAXBExceptionAgain, test code cannot access the module. This time, however, the _maven-surefire-plugin_ needs to be configured:

<plugin>

<artifactId>maven-surefire-plugin</artifactId>

<version>2.20.1</version>

<configuration>

<argLine>--add-modules java.xml.bind</argLine>

</configuration>

?</plugin>

ok,在ｐｏｍ文件里面的插件配置里面加上這句話若河，加一個(gè)配置就搞定了。另外寞宫，在這個(gè)網(wǎng)站中也說明了萧福，在編譯、mvn　spring-boot:run辈赋、打包時(shí)出現(xiàn)這類異常該怎么解決鲫忍，網(wǎng)址

`https://dzone.com/articles/migrating-a-spring-boot-application-to-java-9-comp(可能需要翻墻)`