Spring Boot Property Launcher + EhCache Failed to read schema document - spring-boot

Question

I am working on a Spring Boot(2.3.0.RELEASE) project where there is a need to use a external loader to load few proprietary libraries. Hence we are using Spring's Property Launcher as follows,
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
<configuration>
<layout>ZIP</layout>
<mainClass>com.app.Application</mainClass>
</configuration>
</plugin>
We also use Ehcache version 3.8.1 along with Spring's CacheAutoConfiguration.
The problem we are facing is, for some reason the ehcache schema xsd file is not visible to the classloader and it is failing with the below exception.
I have verified the xsd is present in the exact path that its failing on.
Caused by: org.xml.sax.SAXParseException: schema_reference.4: Failed to read schema document 'jar:file:/C:/workspace/poc/external-loader-poc/target/external-loader-poc.jar!/BOOT-INF/lib/ehcache-3.8.1.jar!/ehcache-core.xsd', because 1) could not find the document; 2) the document could not be read; 3) the root element of the document is not <xsd:schema>.
at com.sun.org.apache.xerces.internal.util.ErrorHandlerWrapper.createSAXParseException(Unknown Source) ~[na:1.8.0_251]
at com.sun.org.apache.xerces.internal.util.ErrorHandlerWrapper.error(Unknown Source) ~[na:1.8.0_251]
at com.sun.org.apache.xerces.internal.impl.XMLErrorReporter.reportError(Unknown Source) ~[na:1.8.0_251]
at com.sun.org.apache.xerces.internal.impl.XMLErrorReporter.reportError(Unknown Source) ~[na:1.8.0_251]
at com.sun.org.apache.xerces.internal.impl.xs.traversers.XSDHandler.reportSchemaErr(Unknown Source) ~[na:1.8.0_251]
at com.sun.org.apache.xerces.internal.impl.xs.traversers.XSDHandler.reportSchemaError(Unknown Source) ~[na:1.8.0_251]
at com.sun.org.apache.xerces.internal.impl.xs.traversers.XSDHandler.getSchemaDocument1(Unknown Source) ~[na:1.8.0_251]
at com.sun.org.apache.xerces.internal.impl.xs.traversers.XSDHandler.getSchemaDocument(Unknown Source) ~[na:1.8.0_251]
at com.sun.org.apache.xerces.internal.impl.xs.traversers.XSDHandler.parseSchema(Unknown Source) ~[na:1.8.0_251]
at com.sun.org.apache.xerces.internal.impl.xs.XMLSchemaLoader.loadSchema(Unknown Source) ~[na:1.8.0_251]
at com.sun.org.apache.xerces.internal.impl.xs.XMLSchemaLoader.loadGrammar(Unknown Source) ~[na:1.8.0_251]
at com.sun.org.apache.xerces.internal.impl.xs.XMLSchemaLoader.loadGrammar(Unknown Source) ~[na:1.8.0_251]
at com.sun.org.apache.xerces.internal.jaxp.validation.XMLSchemaFactory.newSchema(Unknown Source) ~[na:1.8.0_251]
at javax.xml.validation.SchemaFactory.newSchema(Unknown Source) ~[na:1.8.0_251]
at javax.xml.validation.SchemaFactory.newSchema(Unknown Source) ~[na:1.8.0_251]
at org.ehcache.xml.ResourceConfigurationParser.<clinit>(ResourceConfigurationParser.java:67) ~[ehcache-3.8.1.jar!/:na]
... 58 common frames omitted
Caused by: java.io.FileNotFoundException: JAR entry BOOT-INF/lib/ehcache-3.8.1.jar!/ehcache-core.xsd not found in C:\workspace\poc\external-loader-poc\target\external-loader-poc.jar
at sun.net.www.protocol.jar.JarURLConnection.connect(Unknown Source) ~[na:1.8.0_251]
at sun.net.www.protocol.jar.JarURLConnection.getInputStream(Unknown Source) ~[na:1.8.0_251]
at com.sun.org.apache.xerces.internal.impl.XMLEntityManager.setupCurrentEntity(Unknown Source) ~[na:1.8.0_251]
at com.sun.org.apache.xerces.internal.impl.XMLVersionDetector.determineDocVersion(Unknown Source) ~[na:1.8.0_251]
at com.sun.org.apache.xerces.internal.impl.xs.opti.SchemaParsingConfig.parse(Unknown Source) ~[na:1.8.0_251]
However this issue doesn't happen when using the JarLauncher or WarLauncher. It only happens with the PropertyLauncher.
Any suggestions would be of great help.

Answer 1

I had the same issue. I was using SpringBoot 2.3.0.RELEASE with ehcache 3. Just upgraded to Spring boot 2.3.2.RELEASE. The issue resolved. If possible try upgrading the SpringBoot.

Answer 2

I was facing the same issue. I was using SpringBoot 2.5.13 with ehcache 3.9.7.
It seems that as per ehcache 3.x release, either only the new version should be used or the javax.cache API as defined in the JSR-107 specification (more details on https://www.ehcache.org/#using_jsr107_api).
Removing the following from my pom.xml helped resolve the issue
<dependency>
<groupId>javax.cache</groupId>
<artifactId>cache-api</artifactId>
<version>1.1.0</version>
</dependency>