Блог

Я пытаюсь использовать XPathExpression одновременно, но получаю «org.xml.sax.SAXException: синтаксический анализ FWK005 может не вызываться во время синтаксического анализа». Использование ThreadLocal не помогает, происходит сбой, даже если для каждого вызова создается новое XPathExpression. Этот тест Junit воспроизводит проблему:

 package testxpath;

import java.io.StringReader;
import java.util.stream.IntStream;

import javax.xml.xpath.XPathConstants;
import javax.xml.xpath.XPathExpression;
import javax.xml.xpath.XPathFactory;

import org.junit.jupiter.api.Test;
import org.xml.sax.InputSource;

import lombok.SneakyThrows;

class ConcurrentXpathTest {

    private static final String XPATH = "//*[(local-name()='Node')]";
    private static final String XML = "<Node>Something</Node>";

    @Test
    void testConcurrentXpath() {
        IntStream.range(0, 10000)
            .parallel()
            .forEach(v -> parse());
    }

    @SneakyThrows
    private void parse() {
        XPathExpression xPathExpression = XPathFactory.newInstance().newXPath().compile(XPATH);
        xPathExpression.evaluate(new InputSource(new StringReader(XML)), XPathConstants.NODESET);
    }
}
  

Как это можно исправить? Может быть, посоветуйте какие-нибудь альтернативные библиотеки.

Трассировка стека:

 org.xml.sax.SAXException: FWK005 parse may not be called while parsing.
    at com.sun.org.apache.xerces.internal.parsers.DOMParser.parse(DOMParser.java:271)
    at com.sun.org.apache.xerces.internal.jaxp.DocumentBuilderImpl.parse(DocumentBuilderImpl.java:339)
    at com.sun.org.apache.xpath.internal.jaxp.XPathExpressionImpl.evaluate(XPathExpressionImpl.java:291)
    at com.corelogic.clp.tel2.gateway.services.ConcurrentXpathTest.parse(ConcurrentXpathTest.java:43)
    at com.corelogic.clp.tel2.gateway.services.ConcurrentXpathTest.lambda$testConcurrentXpath$0(ConcurrentXpathTest.java:37)
    at java.util.stream.ForEachOps$ForEachOp$OfInt.accept(ForEachOps.java:205)
    at java.util.stream.Streams$RangeIntSpliterator.forEachRemaining(Streams.java:110)
    at java.util.Spliterator$OfInt.forEachRemaining(Spliterator.java:693)
    at java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:481)
    at java.util.stream.ForEachOps$ForEachTask.compute(ForEachOps.java:291)
    at java.util.concurrent.CountedCompleter.exec(CountedCompleter.java:731)
    at java.util.concurrent.ForkJoinTask.doExec(ForkJoinTask.java:289)
    at java.util.concurrent.ForkJoinPool$WorkQueue.runTask(ForkJoinPool.java:1056)
    at java.util.concurrent.ForkJoinPool.runWorker(ForkJoinPool.java:1692)
    at java.util.concurrent.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:157)
--------------- linked to ------------------
javax.xml.xpath.XPathExpressionException: org.xml.sax.SAXException: FWK005 parse may not be called while parsing.

    at com.sun.org.apache.xpath.internal.jaxp.XPathExpressionImpl.evaluate(XPathExpressionImpl.java:294)
    at com.corelogic.clp.tel2.gateway.services.ConcurrentXpathTest.parse(ConcurrentXpathTest.java:43)
    at com.corelogic.clp.tel2.gateway.services.ConcurrentXpathTest.lambda$testConcurrentXpath$0(ConcurrentXpathTest.java:37)
    at java.util.stream.ForEachOps$ForEachOp$OfInt.accept(ForEachOps.java:205)
    at java.util.stream.Streams$RangeIntSpliterator.forEachRemaining(Streams.java:110)
    at java.util.Spliterator$OfInt.forEachRemaining(Spliterator.java:693)
    at java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:481)
    at java.util.stream.ForEachOps$ForEachTask.compute(ForEachOps.java:291)
    at java.util.concurrent.CountedCompleter.exec(CountedCompleter.java:731)
    at java.util.concurrent.ForkJoinTask.doExec(ForkJoinTask.java:289)
    at java.util.concurrent.ForkJoinPool$WorkQueue.runTask(ForkJoinPool.java:1056)
    at java.util.concurrent.ForkJoinPool.runWorker(ForkJoinPool.java:1692)
    at java.util.concurrent.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:157)
Caused by: org.xml.sax.SAXException: FWK005 parse may not be called while parsing.
    at com.sun.org.apache.xerces.internal.parsers.DOMParser.parse(DOMParser.java:271)
    at com.sun.org.apache.xerces.internal.jaxp.DocumentBuilderImpl.parse(DocumentBuilderImpl.java:339)
    at com.sun.org.apache.xpath.internal.jaxp.XPathExpressionImpl.evaluate(XPathExpressionImpl.java:291)
    ... 12 more
--------------- linked to ------------------
javax.xml.xpath.XPathExpressionException: javax.xml.xpath.XPathExpressionException: org.xml.sax.SAXException: FWK005 parse may not be called while parsing.
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
    at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
    at java.util.concurrent.ForkJoinTask.getThrowableException(ForkJoinTask.java:593)
    at java.util.concurrent.ForkJoinTask.reportException(ForkJoinTask.java:677)
    at java.util.concurrent.ForkJoinTask.invoke(ForkJoinTask.java:735)
    at java.util.stream.ForEachOps$ForEachOp.evaluateParallel(ForEachOps.java:160)
    at java.util.stream.ForEachOps$ForEachOp$OfInt.evaluateParallel(ForEachOps.java:189)
    at java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:233)
    at java.util.stream.IntPipeline.forEach(IntPipeline.java:404)
    at java.util.stream.IntPipeline$Head.forEach(IntPipeline.java:560)
    at com.corelogic.clp.tel2.gateway.services.ConcurrentXpathTest.testConcurrentXpath(ConcurrentXpathTest.java:37)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at org.junit.platform.commons.util.ReflectionUtils.invokeMethod(ReflectionUtils.java:532)
    at org.junit.jupiter.engine.execution.ExecutableInvoker.invoke(ExecutableInvoker.java:115)
    at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.lambda$invokeTestMethod$6(TestMethodTestDescriptor.java:171)
    at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:72)
    at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.invokeTestMethod(TestMethodTestDescriptor.java:167)
    at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.execute(TestMethodTestDescriptor.java:114)
    at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.execute(TestMethodTestDescriptor.java:59)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$4(NodeTestTask.java:108)
    at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:72)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:98)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:74)
    at java.util.ArrayList.forEach(ArrayList.java:1257)
    at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.invokeAll(SameThreadHierarchicalTestExecutorService.java:38)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$4(NodeTestTask.java:112)
    at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:72)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:98)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:74)
    at java.util.ArrayList.forEach(ArrayList.java:1257)
    at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.invokeAll(SameThreadHierarchicalTestExecutorService.java:38)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$4(NodeTestTask.java:112)
    at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:72)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:98)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:74)
    at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.submit(SameThreadHierarchicalTestExecutorService.java:32)
    at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor.execute(HierarchicalTestExecutor.java:57)
    at org.junit.platform.engine.support.hierarchical.HierarchicalTestEngine.execute(HierarchicalTestEngine.java:51)
    at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:220)
    at org.junit.platform.launcher.core.DefaultLauncher.lambda$execute$6(DefaultLauncher.java:188)
    at org.junit.platform.launcher.core.DefaultLauncher.withInterceptedStreams(DefaultLauncher.java:202)
    at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:181)
    at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:128)
    at com.intellij.junit5.JUnit5IdeaTestRunner.startRunnerWithArgs(JUnit5IdeaTestRunner.java:71)
    at com.intellij.rt.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:33)
    at com.intellij.rt.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:220)
    at com.intellij.rt.junit.JUnitStarter.main(JUnitStarter.java:53)
Caused by: javax.xml.xpath.XPathExpressionException: org.xml.sax.SAXException: FWK005 parse may not be called while parsing.
    at com.sun.org.apache.xpath.internal.jaxp.XPathExpressionImpl.evaluate(XPathExpressionImpl.java:294)
    at com.corelogic.clp.tel2.gateway.services.ConcurrentXpathTest.parse(ConcurrentXpathTest.java:43)
    at com.corelogic.clp.tel2.gateway.services.ConcurrentXpathTest.lambda$testConcurrentXpath$0(ConcurrentXpathTest.java:37)
    at java.util.stream.ForEachOps$ForEachOp$OfInt.accept(ForEachOps.java:205)
    at java.util.stream.Streams$RangeIntSpliterator.forEachRemaining(Streams.java:110)
    at java.util.Spliterator$OfInt.forEachRemaining(Spliterator.java:693)
    at java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:481)
    at java.util.stream.ForEachOps$ForEachTask.compute(ForEachOps.java:291)
    at java.util.concurrent.CountedCompleter.exec(CountedCompleter.java:731)
    at java.util.concurrent.ForkJoinTask.doExec(ForkJoinTask.java:289)
    at java.util.concurrent.ForkJoinPool$WorkQueue.runTask(ForkJoinPool.java:1056)
    at java.util.concurrent.ForkJoinPool.runWorker(ForkJoinPool.java:1692)
    at java.util.concurrent.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:157)
Caused by: org.xml.sax.SAXException: FWK005 parse may not be called while parsing.
    at com.sun.org.apache.xerces.internal.parsers.DOMParser.parse(DOMParser.java:271)
    at com.sun.org.apache.xerces.internal.jaxp.DocumentBuilderImpl.parse(DocumentBuilderImpl.java:339)
    at com.sun.org.apache.xpath.internal.jaxp.XPathExpressionImpl.evaluate(XPathExpressionImpl.java:291)
    ... 12 more
  

Это связано с ошибкой в некоторых версиях Xerces, даже тех, которые поставляются с JDK / JRE.

Смотрите этот отчет об ошибке. Предположительно, это исправлено в реализации по умолчанию, которая поставляется с Java 9 , но вам может не повезти с 1.8.

Возможно, стоит проверить, какую реализацию Xerces вы используете.

Мы наткнулись на то же самое с Xerces, который поставляется в комплекте с Apache Xalan 2.7.1. Объект, возвращаемый DocumentBuilderFactory.newInstance() , по-видимому, содержит внутреннее состояние, которое не является потокобезопасным, но является общим для экземпляров (или создает другие объекты, которые демонстрируют то же самое). Это, по-видимому, является основной причиной исключения.