Constraint violations produced by invalid parameters of a JAXRS resource method are not immediately returned in the Response returned by the method, causing business methods to be called with invalid values.

public class QueryBeanParam { @Size(min = 1) @QueryParam("foo") private String param; public String getParam() { return param; } } public interface ValidResource { Response getAll(@Valid QueryBeanParam beanParam); } public class RootResource implements ValidResource { @GET @Override public Response getAll(@BeanParam QueryBeanParam beanParam) { System.out.println("beanParam invalid value: " + beanParam.getParam()); // the line above is still called even with an invalid value passed to //beanParam#getparam, but the returned Response contains the list of //violations. return Response.ok().build(); } } public class ValidRootResource { @GET public Response getAll(@Valid @BeanParam QueryBeanParam beanParam) { System.out.println("beanParam invalid value: " + beanParam.getParam()); // the line above is NOT called, as expected, when an invalid value is //passed to //beanParam#getparam. Notice the @Valid annotation is placed //on the class and not on any interface return Response.ok().build(); } }