Wolfgang Seifert ( https://hibernate.atlassian.net/secure/ViewProfile.jspa?accountId=635f717... ) *created* an issue Hibernate ORM ( https://hibernate.atlassian.net/browse/HHH?atlOrigin=eyJpIjoiN2QxZjc0MDgw... ) / Bug ( https://hibernate.atlassian.net/browse/HHH-15646?atlOrigin=eyJpIjoiN2QxZj... ) HHH-15646 ( https://hibernate.atlassian.net/browse/HHH-15646?atlOrigin=eyJpIjoiN2QxZj... ) Using a generic DTO i get a ClassCastException: class sun.reflect.generics.reflectiveObjects.TypeVariableImpl cannot be cast to class java.lang.reflect.ParameterizedType ( https://hibernate.atlassian.net/browse/HHH-15646?atlOrigin=eyJpIjoiN2QxZj... ) Issue Type: Bug Affects Versions: 6.1.5 Assignee: Unassigned Components: hibernate-core Created: 31/Oct/2022 00:24 AM Environment: hibernate 6.1.5 orm / core gradlew test Priority: Major Reporter: Wolfgang Seifert ( https://hibernate.atlassian.net/secure/ViewProfile.jspa?accountId=635f717... ) I was able to reproduce the bug using hibernates own test classes: In org/hibernate/orm/test/sql/exec/SmokeTests.java replace public static class BasicSetterBasedDto { private String code; private String value; public String getCode() { return code; } public void setCode( String code) { this.code = code; } public String getValue() { return value; } public void setValue( String value) { this.value = value; } } with public static class BasicSetterBasedDto<T> { private T code; private T value; public BasicSetterBasedDto() { } public BasicSetterBasedDto(T code, T value) { this.code = code; this.value = value; } public T getCode() { return code; } public void setCode(T code) { this.code = code; } public T getValue() { return value; } public void setValue(T value) { this.value = value; } } and one test will fail with: java.lang.ClassCastException: class sun.reflect.generics.reflectiveObjects.TypeVariableImpl cannot be cast to class java.lang.reflect.ParameterizedType (sun.reflect.generics.reflectiveObjects.TypeVariableImpl and java.lang.reflect.ParameterizedType are in module java.base of loader 'bootstrap') Removing the constructors avoids the problem. ( https://hibernate.atlassian.net/browse/HHH-15646#add-comment?atlOrigin=ey... ) Add Comment ( https://hibernate.atlassian.net/browse/HHH-15646#add-comment?atlOrigin=ey... ) Get Jira notifications on your phone! Download the Jira Cloud app for Android ( https://play.google.com/store/apps/details?id=com.atlassian.android.jira.... ) or iOS ( https://itunes.apple.com/app/apple-store/id1006972087?pt=696495&ct=Em... ) This message was sent by Atlassian Jira (v1001.0.0-SNAPSHOT#100209- sha1:5956172 )