@Entity
@Table(name = "Test")
public class Test {

   private long id;
   private String name;

   @Id
   @GeneratedValue
   public long getId() {
      return id;
   }
   public void setId(long id) {
      this.id = id;
   }

   public String getName() {
      return name;
   }
   public void setName(String name) {
      this.name = name;
   }

@Entity
@Table(name = "Clinic")
public class Clinic {

   private long id;
   private String name;
   
   public Clinic() {
   }
   
   @Id
   @GeneratedValue
   public long getId() {
      return id;
   }
   public void setId(long id) {
      this.id = id;
   }

   public String getName() {
      return name;
   }

   public void setName(String name) {
      this.name = name;
   }
}

@Entity
@Table(name = "TestClinic")
public class TestClinic {

   private float price;
   private Test test;
   private Clinic clinic;

   public float getPrice() {
      return price;
   }
   public void setPrice(float price) {
      this.price = price;
   }

   //@Id
   @ManyToOne
   @JoinColumn(name="test_id")
   public Test getTest() {
      return test;
   }
   public void setTest(Test test) {
      this.test = test;
   }

   //@Id
   @ManyToOne
   @JoinColumn(name="clinic_id")
   public Clinic getClinic() {
      return clinic;
   }
   public void setClinic(Clinic clinic) {
      this.clinic = clinic;
   }
}

Caused by: org.hibernate.AnnotationException: No identifier specified for entity: pl.diagno.model.vo.TestClinic

Caused by: org.hibernate.MappingException: Could not determine type for: pl.diagno.model.vo.Test, for columns: [org.hibernate.mapping.Column(test)]