[hibernate-issues] [Hibernate-JIRA] Resolved: (METAGEN-49) JPAMetaModelEntityProcessor.createMetaModelClasses calls remove within foreach loop (causing a ConcurrentModificationException)

JPAMetaModelEntityProcessor.createMetaModelClasses calls remove within foreach loop (causing a ConcurrentModificationException) ------------------------------------------------------------------------------------------------------------------------------- Key: METAGEN-49 URL: http://opensource.atlassian.com/projects/hibernate/browse/METAGEN-49 Project: Hibernate Metamodel Generator Issue Type: Bug Components: processor Affects Versions: 1.1.0.Final Environment: Hibernate 3.6.0, Java 6 (1.6.0_22), Mac OS X 10.6.5 Reporter: Robin Sander Assignee: Hardy Ferentschik Fix For: 1.1.1.Final Attachments: metagen49.zip Running the annotation processor causes a ConcurrentModificationException. I'm using Maven and the maven-processor-plugin 1.3.7 but from looking into the sources I guess this bug occurs in any environment. JPAMetaModelEntityProcessor.createMetaModelClasses iterates of a Collection<MetaEntity> using a foreach loop and calls remove on the same collection which causes a ConcurrentModificationException. Obviously an iterator should be used instead. Here are the lines concerned: {code:java} Collection<MetaEntity> toProcessEntities = context.getMetaEmbeddables(); while ( !toProcessEntities.isEmpty() ) { Set<MetaEntity> processedEntities = new HashSet<MetaEntity>(); int toProcessCountBeforeLoop = toProcessEntities.size(); for ( MetaEntity entity : toProcessEntities ) { // see METAGEN-36 if ( generatedModelClasses.contains( entity.getQualifiedName() ) ) { toProcessEntities.remove( entity ); // XXX this causes a ConcurrentModificationException continue; } ... {code} Here is the stacktrace: {code} ... [INFO] diagnostic Note: Hibernate JPA 2 Static-Metamodel Generator 1.1.0.Final An annotation processor threw an uncaught exception. Consult the following stack trace for details. java.util.ConcurrentModificationException at java.util.HashMap$HashIterator.nextEntry(HashMap.java:793) at java.util.HashMap$ValueIterator.next(HashMap.java:822) at org.hibernate.jpamodelgen.JPAMetaModelEntityProcessor.createMetaModelClasses(JPAMetaModelEntityProcessor.java:153) at org.hibernate.jpamodelgen.JPAMetaModelEntityProcessor.process(JPAMetaModelEntityProcessor.java:133) at com.sun.tools.javac.processing.JavacProcessingEnvironment.callProcessor(JavacProcessingEnvironment.java:625) at com.sun.tools.javac.processing.JavacProcessingEnvironment.discoverAndRunProcs(JavacProcessingEnvironment.java:554) at com.sun.tools.javac.processing.JavacProcessingEnvironment.doProcessing(JavacProcessingEnvironment.java:699) at com.sun.tools.javac.main.JavaCompiler.processAnnotations(JavaCompiler.java:981) at com.sun.tools.javac.main.JavaCompiler.compile(JavaCompiler.java:727) at com.sun.tools.javac.main.Main.compile(Main.java:353) at com.sun.tools.javac.api.JavacTaskImpl.call(JavacTaskImpl.java:115) at org.bsc.maven.plugin.processor.AbstractAnnotationProcessorMojo.executeWithExceptionsHandled(AbstractAnnotationProcessorMojo.java:261) at org.bsc.maven.plugin.processor.AbstractAnnotationProcessorMojo.execute(AbstractAnnotationProcessorMojo.java:129) at org.apache.maven.plugin.DefaultPluginManager.executeMojo(DefaultPluginManager.java:490) {code}