package ejava.examples.orm.core.annotated;
   
   import java.io.Serializable;
   
   import javax.persistence.*;
   
   /**
    * This class provides an example of a primary key class that can be 
    * embedded into the referenced class. The containing class will simply
   * use an instance of this class rather than having separate fields that
   * match the fields of this class.
   */
  @Embeddable
  public class NapsackPK implements Serializable {
      private static final long serialVersionUID = 1L;
  
      @Column(name="NAPSACK_MAKE") //maps field to column of containing class
      private String make;
      @Column(name="NAPSACK_MODEL")//maps field to column of containing class
      private String model;
      
      public NapsackPK() {}
      public NapsackPK(String make, String model) {
          this.make = make;
          this.model = model;
      }
      
      public String getMake() { return make; }
      public void setMake(String make) {
  		this.make = make;
  	}
      public String getModel() { return model; }
      public void setModel(String model) {
  		this.model = model;
  	}
  
      public int hashCode() { return make.hashCode() + model.hashCode(); }
      public boolean equals(Object obj) {
          try {
              if (this == obj) return true;
              return make.equals(((NapsackPK)obj).getMake()) &&
                     model.equals(((NapsackPK)obj).getModel());
              
          } catch (Throwable ignored) { //catch NP & Cast Exceptions 
              return false;
          }
      }
      
      public String toString() {
          return new StringBuilder()
              .append(super.toString())	       
              .append(", make=").append(make)
              .append(", model=").append(model)
              .toString();
      }
  }