OSGi/Equinox application launch fails due to "301 Moved Permanently" when resolving XSD

We have an older (maintenance branch) version of a OSGi/Java application that relies on Spring 4.2.6.

Recently, when attempting to launch the application in a new developer workspace, the launch fails. It seems the root cause is that an XSD file has moved. Specifically, the HTTP request is redirected to HTTPS:

Now, this isn't something I can control. So I'd like to figure out:

Can I disable XSD validation/loading for my application, or
Do I need to upgrade to a newer version of Spring? I'd like to avoid this as it's a maintenance branch for which we're providing critical bug-only updates.

The stack:

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.test.context.TestContextManager.prepareTestInstance(TestContextManager.java:228)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.createTest(SpringJUnit4ClassRunner.java:230)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner$1.runReflectiveCall(SpringJUnit4ClassRunner.java:289)
    at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.methodBlock(SpringJUnit4ClassRunner.java:291)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:249)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:89)
    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:193)
    at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:86)
    at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:459)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:675)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:382)
    at org.eclipse.pde.internal.junit.runtime.RemotePluginTestRunner.main(RemotePluginTestRunner.java:62)
    at org.eclipse.pde.internal.junit.runtime.CoreTestApplication.run(CoreTestApplication.java:23)
    at org.eclipse.pde.internal.junit.runtime.NonUIThreadTestApplication.runApp(NonUIThreadTestApplication.java:56)
    at org.eclipse.pde.internal.junit.runtime.NonUIThreadTestApplication.start(NonUIThreadTestApplication.java:48)
    at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:196)
    at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication(EclipseAppLauncher.java:134)
    at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start(EclipseAppLauncher.java:104)
    at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:380)
    at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:235)
    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.eclipse.equinox.launcher.Main.invokeFramework(Main.java:669)
    at org.eclipse.equinox.launcher.Main.basicRun(Main.java:608)
    at org.eclipse.equinox.launcher.Main.run(Main.java:1515)
    at org.eclipse.equinox.launcher.Main.main(Main.java:1488)
Caused by: org.springframework.beans.factory.xml.XmlBeanDefinitionStoreException: Line 2 in XML document from OSGi resource[classpath:/test-spring-config.xml|bnd.id=11|bnd.sym=com.mycompany.myapplication] is invalid; nested exception is org.xml.sax.SAXParseException; systemId: http://www.osgi.org/xmlns/blueprint/v1.0.0/blueprint.xsd; lineNumber: 2; columnNumber: 35; s4s-elt-character: Non-whitespace characters are not allowed in schema elements other than 'xs:appinfo' and 'xs:documentation'. Saw '301 Moved Permanently'.
    at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.doLoadBeanDefinitions(XmlBeanDefinitionReader.java:399)
    at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.loadBeanDefinitions(XmlBeanDefinitionReader.java:336)
    at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.loadBeanDefinitions(XmlBeanDefinitionReader.java:304)
    at org.springframework.beans.factory.support.AbstractBeanDefinitionReader.loadBeanDefinitions(AbstractBeanDefinitionReader.java:181)
    at org.springframework.beans.factory.support.AbstractBeanDefinitionReader.loadBeanDefinitions(AbstractBeanDefinitionReader.java:217)
    at org.springframework.beans.factory.support.AbstractBeanDefinitionReader.loadBeanDefinitions(AbstractBeanDefinitionReader.java:188)
    at org.eclipse.gemini.blueprint.context.support.OsgiBundleXmlApplicationContext.loadBeanDefinitions(OsgiBundleXmlApplicationContext.java:170)
    at org.eclipse.gemini.blueprint.context.support.OsgiBundleXmlApplicationContext.loadBeanDefinitions(OsgiBundleXmlApplicationContext.java:140)
    at org.springframework.context.support.AbstractRefreshableApplicationContext.refreshBeanFactory(AbstractRefreshableApplicationContext.java:129)
    at org.springframework.context.support.AbstractApplicationContext.obtainFreshBeanFactory(AbstractApplicationContext.java:609)
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:510)
    at org.eclipse.gemini.blueprint.context.support.AbstractDelegatedExecutionApplicationContext.access$301(AbstractDelegatedExecutionApplicationContext.java:60)
    at org.eclipse.gemini.blueprint.context.support.AbstractDelegatedExecutionApplicationContext$1.run(AbstractDelegatedExecutionApplicationContext.java:168)
    at org.eclipse.gemini.blueprint.util.internal.PrivilegedUtils.executeWithCustomTCCL(PrivilegedUtils.java:85)
    at org.eclipse.gemini.blueprint.context.support.AbstractDelegatedExecutionApplicationContext.normalRefresh(AbstractDelegatedExecutionApplicationContext.java:164)
    at org.eclipse.gemini.blueprint.context.support.AbstractDelegatedExecutionApplicationContext$NoDependenciesWaitRefreshExecutor.refresh(AbstractDelegatedExecutionApplicationContext.java:78)
    at org.eclipse.gemini.blueprint.context.support.AbstractDelegatedExecutionApplicationContext.refresh(AbstractDelegatedExecutionApplicationContext.java:157)
    at com.mycompany.myapplication.OsgiBundleXmlContextLoader.loadContext(OsgiBundleXmlContextLoader.java:26)
    at com.mycompany.myapplication.OsgiBundleXmlContextLoader.loadContext(OsgiBundleXmlContextLoader.java:32)
    at org.springframework.test.context.cache.DefaultCacheAwareContextLoaderDelegate.loadContextInternal(DefaultCacheAwareContextLoaderDelegate.java:98)
    at org.springframework.test.context.cache.DefaultCacheAwareContextLoaderDelegate.loadContext(DefaultCacheAwareContextLoaderDelegate.java:116)
    ... 41 more
Caused by: org.xml.sax.SAXParseException; systemId: http://www.osgi.org/xmlns/blueprint/v1.0.0/blueprint.xsd; lineNumber: 2; columnNumber: 35; s4s-elt-character: Non-whitespace characters are not allowed in schema elements other than 'xs:appinfo' and 'xs:documentation'. Saw '301 Moved Permanently'.
    at com.sun.org.apache.xerces.internal.util.ErrorHandlerWrapper.createSAXParseException(ErrorHandlerWrapper.java:203)
    at com.sun.org.apache.xerces.internal.util.ErrorHandlerWrapper.error(ErrorHandlerWrapper.java:134)
    at com.sun.org.apache.xerces.internal.impl.XMLErrorReporter.reportError(XMLErrorReporter.java:396)
    at com.sun.org.apache.xerces.internal.impl.XMLErrorReporter.reportError(XMLErrorReporter.java:327)
    at com.sun.org.apache.xerces.internal.impl.xs.opti.SchemaDOMParser.characters(SchemaDOMParser.java:198)
    at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanDocument(XMLDocumentFragmentScannerImpl.java:455)
    at com.sun.org.apache.xerces.internal.impl.xs.opti.SchemaParsingConfig.parse(SchemaParsingConfig.java:630)
    at com.sun.org.apache.xerces.internal.impl.xs.opti.SchemaParsingConfig.parse(SchemaParsingConfig.java:686)
    at com.sun.org.apache.xerces.internal.impl.xs.opti.SchemaDOMParser.parse(SchemaDOMParser.java:530)
    at com.sun.org.apache.xerces.internal.impl.xs.traversers.XSDHandler.getSchemaDocument(XSDHandler.java:2181)
    at com.sun.org.apache.xerces.internal.impl.xs.traversers.XSDHandler.parseSchema(XSDHandler.java:578)
    at com.sun.org.apache.xerces.internal.impl.xs.XMLSchemaLoader.loadSchema(XMLSchemaLoader.java:610)
    at com.sun.org.apache.xerces.internal.impl.xs.XMLSchemaLoader.processJAXPSchemaSource(XMLSchemaLoader.java:774)
    at com.sun.org.apache.xerces.internal.impl.xs.XMLSchemaLoader.loadSchema(XMLSchemaLoader.java:599)
    at com.sun.org.apache.xerces.internal.impl.xs.XMLSchemaValidator.findSchemaGrammar(XMLSchemaValidator.java:2447)
    at com.sun.org.apache.xerces.internal.impl.xs.XMLSchemaValidator.handleStartElement(XMLSchemaValidator.java:1768)
    at com.sun.org.apache.xerces.internal.impl.xs.XMLSchemaValidator.startElement(XMLSchemaValidator.java:741)
    at com.sun.org.apache.xerces.internal.impl.XMLNSDocumentScannerImpl.scanStartElement(XMLNSDocumentScannerImpl.java:374)
    at com.sun.org.apache.xerces.internal.impl.XMLNSDocumentScannerImpl$NSContentDriver.scanRootElementHook(XMLNSDocumentScannerImpl.java:613)
    at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl$FragmentContentDriver.next(XMLDocumentFragmentScannerImpl.java:3132)
    at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl$PrologDriver.next(XMLDocumentScannerImpl.java:852)
    at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl.next(XMLDocumentScannerImpl.java:602)
    at com.sun.org.apache.xerces.internal.impl.XMLNSDocumentScannerImpl.next(XMLNSDocumentScannerImpl.java:112)
    at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanDocument(XMLDocumentFragmentScannerImpl.java:505)
    at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:842)
    at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:771)
    at com.sun.org.apache.xerces.internal.parsers.XMLParser.parse(XMLParser.java:141)
    at com.sun.org.apache.xerces.internal.parsers.DOMParser.parse(DOMParser.java:243)
    at com.sun.org.apache.xerces.internal.jaxp.DocumentBuilderImpl.parse(DocumentBuilderImpl.java:339)
    at org.springframework.beans.factory.xml.DefaultDocumentLoader.loadDocument(DefaultDocumentLoader.java:76)
    at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.doLoadDocument(XmlBeanDefinitionReader.java:429)
    at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.doLoadBeanDefinitions(XmlBeanDefinitionReader.java:391)
    ... 61 more

The stack refers to line 2 of one of our XML configuration files, but it simply contains:

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:tx="http://www.springframework.org/schema/tx"
    xmlns:sec="http://www.springframework.org/schema/security"
    xsi:schemaLocation="http://www.springframework.org/schema/beans 
                        http://www.springframework.org/schema/beans/spring-beans-4.2.xsd
                        http://www.springframework.org/schema/tx 
                        http://www.springframework.org/schema/tx/spring-tx-4.2.xsd
                        http://www.springframework.org/schema/security
                        http://www.springframework.org/schema/security/spring-security-4.1.xsd
                        http://www.springframework.org/schema/security/oauth2
                        http://www.springsecurity.org/schema/security/spring-security-oauth2-1.0.xsd">
...

Note that if I change line 2 to read:

<beans>

The result is the same.

Solution

I've been able to replicate the issue and find a workaround for the 301 redirect on the DTD.

First, I've set up a test in which the AplicationContext is constructed based on an XML file with a 301 reference:

import org.junit.Test;
import org.springframework.context.ApplicationContext;

public class MovedDtdTest {

  @Test
  public void test()throws Exception {
    ApplicationContext context = new FileSystemXmlApplicationContext("classpath:test.xml");
  }
}

test.xml:

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
                        http://www.nos.nl">
</beans>

Which resulted in the same exception:

org.springframework.beans.factory.xml.XmlBeanDefinitionStoreException:
Line 2 in XML document from class path resource [test.xml] is invalid;
nested exception is org.xml.sax.SAXParseException; systemId: http://nos.nl/;
lineNumber: 2; columnNumber: 35; s4s-elt-character: Non-whitespace characters
are not allowed in schema elements other than 'xs:appinfo' and 'xs:documentation'.
Saw '301 Moved Permanently'.
...
at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.doLoadBeanDefinitions(XmlBeanDefinitionReader.java:392)

Then, I started debugging the stack trace and noticed that the following static attribute is present in the file XmlBeanDefinitionReader:

public static final int VALIDATION_NONE = XmlValidationModeDetector.VALIDATION_NONE;

Which is set in org.springframework.beans.factory.xml.XmlBeanDefinitionReader#setValidating:

public void setValidating(boolean validating) {
    this.validationMode = (validating ? VALIDATION_AUTO : VALIDATION_NONE);
    this.namespaceAware = !validating;
}

Optionally, you could add a breakpoint in the method above and set validating to false in order to test it.

After googling on how to override the XmlBeanDefinitionReader, I came across an old StackOverflow post on how to create and use a custom NamespaceHandlerResolver

I changed it to alter the behaviour of the XmlBeanDefinitionReader instead of the NamespaceHandlerResolver:

public class CustomClassPathXmlApplicationContext extends FileSystemXmlApplicationContext {

  public CustomClassPathXmlApplicationContext(String... configLocations) throws BeansException {
    super(configLocations, true, null);
  }

  @Override
  protected void initBeanDefinitionReader(XmlBeanDefinitionReader reader) {
    super.initBeanDefinitionReader(reader);
    reader.setValidating(false);
  }
}

And edited my test to load the ApplicationContext using the CustomClassPathXmlApplicationContext:

  @Test
  public void test()throws Exception {
    ApplicationContext context = new CustomClassPathXmlApplicationContext("classpath:test.xml");
  }

The test now passes with:

18:28:41.753 [main] DEBUG xxx.xx.xx.CustomClassPathXmlApplicationContext - Refreshing xx.xx.xx.x.CustomClassPathXmlApplicationContext@2bbf4b8b
18:28:42.014 [main] DEBUG org.springframework.beans.factory.xml.XmlBeanDefinitionReader - Loaded 0 bean definitions from class path resource [test.xml]

I don't know how the ApplicationContext is loaded within your application, but as you mentioned a 'legacy' application I used XmlConfig instead of JavaConfig.

I hope you'll be able to find some way to modify the behavior of the XmlBeanDefinitionReader in your ApplicationContext. It needs to happen in an early stage of the Spring lifecycle as the XML is parsed before the beans are created.