Hash coordinate map display in sleep mode with annotation

Question

I just started using sleep mode, and I'm trying to map the distance between two coordinates to a hash map. There can be many links from one "FromCoordinate" to another "ToCoordinate". I'm not sure if I implemented this correctly. What annotations do I need to map to this MashMap? Thanks

HashMap> coordWalkingConnections = new HashMap> ();

@Entity
@Table(name = "COORDCONNECTIONS")
public class CoordinateConnection implements Serializable{

    private static final long serialVersionUID = -1624745319005591573L;

    /** auto increasing id number */
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "ID")
    @id
    private int id;

    @Embedded
    public FromCoordinate fromCoord;

    @Embedded
    public ToCoordinate toCoord;


HashMap<FromCoordinate, ArrayList<ToCoordinate >> coordWalkingConnections = new HashMap<FromCoordinate, ArrayList<ToCoordinate >>();

}

public class FromCoordinate implements ICoordinate
{
    @Column(name = "FROM_LAT")
    private double latitude;

    @Column(name = "FROM_LNG")
    private double longitude;
}

public class ToCoordinate implements ICoordinate
{

    @Column(name = "TO_LAT")
    private double latitude;

    @Column(name = "TO_LNG")
    private double longitude;

    @Column(name = "DISTANCE")
    private double distance;
}

DATABASE STRUCTURE
id  FROM_LAT    FROM_LNG    TO_LAT      TO_LNG      Dist
1   43.352669   -6.264341   43.350012   -6.260653   0.38
2   43.352669   -6.264341   43.352669   -6.264341   0.00
3   46.352669   -6.264341   43.353373   -6.262013   0.17
4   47.352465   -6.265865   43.351290   -6.261200   0.25
5   45.452578   -6.265768   43.352788   -6.264396   0.01
6   45.452578   -6.265768   45.782788   -6.234523   0.01
    .....
    ...
    .

Example HashMap for HashMap<Coordinate, ArrayList<Coordinate>>


<KEY{43.352669  -6.264341}, Arraylist VALUES{(43.350012,-6.260653,0.383657),  (43.352669, -6.264341, 0.000095), (43.353373, -6.262013,  0.173201)}>
<KEY{47.352465  -6.265865}, Arraylist VALUES{(43.351290,-6.261200,0.258781)}>
<KEY{45.452578  -6.265768}, Arraylist VALUES{(43.352788,-6.264396,0.013726),(45.782788,-6.234523,0.017726)}>

Answer 1

Well, in my opinion, you should use the interface type of the interface when initializing.

Instead:

HashMap<FromCoordinate, ArrayList<ToCoordinate >> coordWalkingConnections = new HashMap<FromCoordinate, ArrayList<ToCoordinate >>();

using:

Map<FromCoordinate, List<ToCoordinate >> coordWalkingConnections = new HashMap<FromCoordinate, ArrayList<ToCoordinate >>();

: http://docs.jboss.org/hibernate/core/3.3/reference/en/html/collections.html, :

java.util.Set, java.util.Collection, java.util.List, java.util.Map, java.util.SortedSet, java.util.SortedMap , ( " " org.hibernate.usertype.UserCollectionType.)

, HashSet. (). , persist(), , Hibernate HashSet Hibernate Set. :

, . , .