import com.alibaba.dubbo.rpc.protocol.rest.support.ContentType; //导入依赖的package包/类
public Response toResponse(RpcException e) {
    // TODO do more sophisticated exception handling and output
    if (e.getCause() instanceof ConstraintViolationException) {
        return handleConstraintViolationException((ConstraintViolationException) e.getCause());
    }
    // we may want to avoid exposing the dubbo exception details to certain clients
    // TODO for now just do plain text output
    return Response.status(Response.Status.INTERNAL_SERVER_ERROR).entity("Internal server error: " + e.getMessage()).type(ContentType.TEXT_PLAIN_UTF_8).build();
}
 

import com.alibaba.dubbo.rpc.protocol.rest.support.ContentType; //导入依赖的package包/类
protected Response handleConstraintViolationException(ConstraintViolationException cve) {
    ViolationReport report = new ViolationReport();
    for (ConstraintViolation cv : cve.getConstraintViolations()) {
        report.addConstraintViolation(new RestConstraintViolation(
                cv.getPropertyPath().toString(),
                cv.getMessage(),
                cv.getInvalidValue() == null ? "null" : cv.getInvalidValue().toString()));
    }
    // TODO for now just do xml output
    return Response.status(Response.Status.INTERNAL_SERVER_ERROR).entity(report).type(ContentType.TEXT_XML_UTF_8).build();
}