java 8反射不起作用

问题描述 投票：5回答：1

我们在项目中使用hibernate验证器和动态类加载（通过加载类进入单独的类加载器）。在我们意识到不需要该类之后，我们删除对类和类加载器的所有引用，然后GC收集它。

我们得到的结果：应用程序启动后的一段时间，java反射停止工作。

java.lang.reflect.UndeclaredThrowableException: null
    at com.sun.proxy.$Proxy253.equals(Unknown Source)
    at org.hibernate.validator.internal.engine.constraintvalidation.ConstraintValidatorManager$CacheKey.equals(ConstraintValidatorManager.java:287)
    at java.util.concurrent.ConcurrentHashMap.get(ConcurrentHashMap.java:940)
    at org.hibernate.validator.internal.engine.constraintvalidation.ConstraintValidatorManager.getInitializedValidator(ConstraintValidatorManager.java:104)
    at org.hibernate.validator.internal.engine.constraintvalidation.ConstraintTree.getConstraintValidatorNoUnwrapping(ConstraintTree.java:301)
    at org.hibernate.validator.internal.engine.constraintvalidation.ConstraintTree.getConstraintValidatorInstanceForAutomaticUnwrapping(ConstraintTree.java:242)
    at org.hibernate.validator.internal.engine.constraintvalidation.ConstraintTree.getInitializedConstraintValidator(ConstraintTree.java:163)
    at org.hibernate.validator.internal.engine.constraintvalidation.ConstraintTree.validateConstraints(ConstraintTree.java:116)
    at org.hibernate.validator.internal.engine.constraintvalidation.ConstraintTree.validateComposingConstraints(ConstraintTree.java:396)
    at org.hibernate.validator.internal.engine.constraintvalidation.ConstraintTree.validateConstraints(ConstraintTree.java:98)
    at org.hibernate.validator.internal.engine.constraintvalidation.ConstraintTree.validateConstraints(ConstraintTree.java:87)
    at org.hibernate.validator.internal.metadata.core.MetaConstraint.validateConstraint(MetaConstraint.java:73)
    at org.hibernate.validator.internal.engine.ValidatorImpl.validateMetaConstraint(ValidatorImpl.java:616)
    at org.hibernate.validator.internal.engine.ValidatorImpl.validateConstraint(ValidatorImpl.java:581)
    at org.hibernate.validator.internal.engine.ValidatorImpl.validateConstraintsForSingleDefaultGroupElement(ValidatorImpl.java:527)
    at org.hibernate.validator.internal.engine.ValidatorImpl.validateConstraintsForDefaultGroup(ValidatorImpl.java:495)
    at org.hibernate.validator.internal.engine.ValidatorImpl.validateConstraintsForCurrentGroup(ValidatorImpl.java:460)
    at org.hibernate.validator.internal.engine.ValidatorImpl.validateInContext(ValidatorImpl.java:410)
    at org.hibernate.validator.internal.engine.ValidatorImpl.validate(ValidatorImpl.java:207)
    at org.springframework.validation.beanvalidation.SpringValidatorAdapter.validate(SpringValidatorAdapter.java:281)
    ... Many spring filters calls ...
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    at org.springframework.web.multipart.support.MultipartFilter.doFilterInternal(MultipartFilter.java:122)
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
    at org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:346)
    at org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:262)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    at *someAwesomePackage*.microservice.rest.spring.webapp.CabinetRequestFilter.doFilterInternal(CabinetRequestFilter.java:98)
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
    at org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:346)
    at org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:262)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:198)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:81)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:342)
    at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:803)
    at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)
    at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:790)
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1459)
    at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
    at java.lang.Thread.run(Thread.java:748)
Caused by: java.lang.reflect.InvocationTargetException: null
    at sun.reflect.GeneratedMethodAccessor268.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at org.hibernate.validator.internal.util.annotationfactory.AnnotationProxy.invoke(AnnotationProxy.java:69)
    ... 260 common frames omitted
Caused by: java.lang.NullPointerException: null
    at org.hibernate.validator.internal.util.annotationfactory.AnnotationProxy.getAnnotationMemberValue(AnnotationProxy.java:248)
    at org.hibernate.validator.internal.util.annotationfactory.AnnotationProxy.equals(AnnotationProxy.java:104)
    ... 264 common frames omitted

在这个地方发生错误（来自java.lang.Class.java的方法）：

 private static Method searchMethods(Method[] methods,
                                    String name,
                                    Class<?>[] parameterTypes) {
    Method res = null;
    String internedName = name.intern();
    for (int i = 0; i < methods.length; i++) {
        Method m = methods[i];
        if (m.getName() == internedName
            && arrayContentsEq(parameterTypes, m.getParameterTypes())
            && (res == null
                || res.getReturnType().isAssignableFrom(m.getReturnType())))
            res = m;
    }
    return (res == null ? res : getReflectionFactory().copyMethod(res));
}

类有方法，但m.getName () == internedName的比较是假的。比较返回false，因为方法的名称未被实现。

如果我从debug调用m.getName (). Intern () == internedName，它返回true。但是'searchMethods'方法来自'java.lang.Class'。

这总是在应用程序启动一段时间后发生。

有人遇到过这样的问题吗？

编辑（25/12/2017）：

不仅hibernate验证器失败，xml解析也失败了！

XML示例：

<SELFCARE>
    <SESSION_ID>***</SESSION_ID>
</SELFCARE>

映射示例：

@XmlRootElement(name = "SELFCARE")
@XmlAccessorType(XmlAccessType.FIELD)
public class Session {

    @XmlElement(name = "SESSION_ID")
    private String sessionId;
}

解析异常：

WARN  2017.12.25 20:00:05.991 +0300 org.apache.cxf.jaxrs.provider.AbstractJAXBProvider             javax.xml.bind.UnmarshalException
- with linked exception:
[com.sun.istack.SAXParseException2; lineNumber: 1; columnNumber: 1; unexpected element (uri:"", local:"SELFCARE"). Expected elements are <{}SELFCARE>]
    at com.sun.xml.bind.v2.runtime.unmarshaller.UnmarshallerImpl.handleStreamException(UnmarshallerImpl.java:483)
    at com.sun.xml.bind.v2.runtime.unmarshaller.UnmarshallerImpl.unmarshal0(UnmarshallerImpl.java:417)
    at com.sun.xml.bind.v2.runtime.unmarshaller.UnmarshallerImpl.unmarshal(UnmarshallerImpl.java:386)
    at org.apache.cxf.jaxrs.provider.JAXBElementProvider.unmarshalFromInputStream(JAXBElementProvider.java:294)
    at org.apache.cxf.jaxrs.provider.JAXBElementProvider.doUnmarshal(JAXBElementProvider.java:245)

但是如果反射正在起作用，那么映射是正确的并且有效

java reflection hibernate-validator dynamic-class-loaders string-interning
1个回答
1
投票

从堆栈跟踪中，我怀疑你正在使用HV 5.x.我对吗？

这个问题似乎与您拥有代理的事实有关。我认为这可能与注释是关键的一部分有关。

你能试试HV 6.0.7.Final吗？我们摆脱了缓存键中的注释，因此它可以解决您的问题。

小心，我们更改了groupId：它现在是org.hibernate.validator（而不是org.hibernate） - 如果HV依赖关系从另一个工件传递，请小心，如果需要，添加排除项。

您还需要javax.el依赖项：

<dependency>
   <groupId>org.glassfish</groupId>
   <artifactId>javax.el</artifactId>
   <version>3.0.1-b08</version>
</dependency>

（小心，你的依赖项中可能还有其他javax.el工件，所以一定要只有这个 - Eclipse的依赖层次结构视图可能有帮助）

您还需要validation-api 2.0.1.Final（它可以通过HV传递，但如果您明确声明它，则可能需要更改版本）。

除此之外，您不应该有任何兼容性问题（除非您使用价值处理等实验性功能）：它是一个替代品。 HV 6也明显更快，因此它应该是一个双赢的局面。

请随时报告您的升级问题，我会帮忙。

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