可能是一个基本问题的时间，但我找不到答案。我意识到这个异常意味着这个类丢失了，但是你在哪里找到这个东西？
堆栈跟踪：
WARN Worker-0 org.hibernate.cfg.AnnotationConfiguration - Unable to apply constraints on DDL for Annotations
java.lang.ClassNotFoundException: Annotations
at org.eclipse.osgi.internal.loader.BundleLoader.findClassInternal(BundleLoader.java:506)
at org.eclipse.osgi.internal.loader.BundleLoader.findClass(BundleLoader.java:422)
at org.eclipse.osgi.internal.loader.BundleLoader.findClass(BundleLoader.java:410)
at org.eclipse.osgi.internal.baseadaptor.DefaultClassLoader.loadClass(DefaultClassLoader.java:107)
at java.lang.ClassLoader.loadClass(ClassLoader.java:248)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:169)
at org.hibernate.util.ReflectHelper.classForName(ReflectHelper.java:192)
at org.hibernate.cfg.AnnotationConfiguration.applyHibernateValidatorLegacyConstraintsOnDDL(AnnotationConfiguration.java:463)
at org.hibernate.cfg.AnnotationConfiguration.applyConstraintsToDDL(AnnotationConfiguration.java:428)
at org.hibernate.cfg.AnnotationConfiguration.secondPassCompile(AnnotationConfiguration.java:403)
at org.hibernate.cfg.Configuration.generateSchemaCreationScript(Configuration.java:920)
at org.hibernate.tool.hbm2ddl.SchemaExport.<init>(SchemaExport.java:129)
at org.hibernate.tool.hbm2ddl.SchemaExport.<init>(SchemaExport.java:91)
at org.hibernate.tool.hbm2x.Hbm2DDLExporter.doStart(Hbm2DDLExporter.java:159)
at org.hibernate.tool.hbm2x.AbstractExporter.start(AbstractExporter.java:95)
at org.hibernate.eclipse.launch.CodeGenerationLaunchDelegate$1.execute(CodeGenerationLaunchDelegate.java:408)
at org.hibernate.console.execution.DefaultExecutionContext.execute(DefaultExecutionContext.java:63)
at org.hibernate.console.ConsoleConfiguration.execute(ConsoleConfiguration.java:72)
at org.hibernate.eclipse.launch.CodeGenerationLaunchDelegate.runExporters(CodeGenerationLaunchDelegate.java:383)
at org.hibernate.eclipse.launch.CodeGenerationLaunchDelegate.launch(CodeGenerationLaunchDelegate.java:310)
at org.eclipse.debug.internal.core.LaunchConfiguration.launch(LaunchConfiguration.java:853)
at org.eclipse.debug.internal.core.LaunchConfiguration.launch(LaunchConfiguration.java:702)
at org.eclipse.debug.internal.ui.DebugUIPlugin.buildAndLaunch(DebugUIPlugin.java:924)
at org.eclipse.debug.internal.ui.DebugUIPlugin$8.run(DebugUIPlugin.java:1128)
at org.eclipse.core.internal.jobs.Worker.run(Worker.java:54)
TIA