problem mapping map-key-many-to-many

Dencel · **Joined:** Tue Jan 27, 2004 12:22 pm **Posts:** 103

Hibernate version:3.2.1 GA

Mapping code snippet:

Code:

      <map name="labelReports" table="debtor_label_reports" cascade="all">
         <key column="debId" />
         <map-key-many-to-many column="sortOrderId" class="SortOrder"/>
         <many-to-many column="reportId" class="nl.dgoexpress.webclient.model.report.LabelReport"/>
      </map>

Java code:

Code:

      Debtor debtor = service.getDebtor();
      SortOrder sortOrder =service.getSortOrder();
      Map<SortOrder,LabelReport> reports = debtor.getLabelReports();
      Set<SortOrder> keySet = reports.keySet();
      for(SortOrder key:keySet)
      {
         boolean equals1 = key.equals(sortOrder);
      }
        boolean equals2 = keySet.contains(sortOrder);

equals1 resolves to true.
equals2 resolves to false.

Is this by design or is this an error on my side?

thatmikewilliams · **Posted:** Wed Aug 08, 2007 10:18 am

Does your SortOrder class override BOTH equals and hashCode?

Dencel · **Joined:** Tue Jan 27, 2004 12:22 pm **Posts:** 103

yes.

SortOrder.java

Code:

   @Override
   public boolean equals(Object other) {
        if ( (this == other ) ) return true;
        if ( !(other instanceof SortOrder) ) return false;
        SortOrder castOther = (SortOrder) other;
        
        return new EqualsBuilder()
            .append(this.getName(), castOther.getName())
            .isEquals();
   }
   
   @Override
   public int hashCode() {
      return new HashCodeBuilder()
         .append(this.getName())
         .hashCode();
   }

LabelReport.java

Code:

   @Override
   public boolean equals(Object other) {
        if ( (this == other ) ) return true;
        if ( !(other instanceof Report) ) return false;
        Report castOther = (Report) other;
        
        return new EqualsBuilder()
            .append(this.getName(), castOther.getName())
            .isEquals();
   }
   
   @Override
   public int hashCode() {
      return new HashCodeBuilder()
         .append(this.getName())
         .hashCode();
   }

Anyway, I solved it using a composite-element and switching from map to set.

thatmikewilliams · **Posted:** Wed Aug 08, 2007 11:01 am

Your hashCode methods are wrong in both classes. You're returning the hashCode of the HashCodeBuilder instance, not the generated value from toHashCode(). Better check other places you've used HashCodeBuilder.

Code:

return new HashCodeBuilder() 
         .append(this.getName()) 
         .hashCode(); // <----------- hash code of builder instance

return new HashCodeBuilder() 
         .append(this.getName()) 
         .toHashCode();  // <-------- hash code generated by builder