@Converter
public class PostgresInetConverter implements AttributeConverter<Object, PGobject> {

    @Override
    public PGinet convertToDatabaseColumn(Object objectValue) {

        if (objectValue == null) {
            return null;
        } else if (objectValue instanceof InetAddress) {
            try {
                InetAddress inet = (InetAddress) objectValue;

                return new PGinet(inet.getHostAddress());
            } catch (SQLException ex) {
                throw new IllegalArgumentException("Unable to convert an object value", ex);
            }
        } else if (objectValue instanceof String) {
            try {
                return new PGinet((String) objectValue);
            } catch (SQLException ex) {
                throw new IllegalArgumentException("Unable to convert an object value", ex);
            }
        }

        throw new IllegalArgumentException("Unable to convert object value of type "
                + objectValue.getClass().getName() + " into a "
                + PGinet.class.getName());
    }

    @Override
    public InetAddress convertToEntityAttribute(PGobject dataValue) {
        if (dataValue == null) {
            return null;
        } else if (dataValue instanceof PGobject) {
            PGobject net = (PGobject) dataValue;
            try {
                String ip = net.getValue().split("/")[0];
                return InetAddress.getByName(ip);
            } catch (UnknownHostException ex) {
                throw new IllegalArgumentException("Unable to convert an object value", ex);
            }
        }

        throw new IllegalArgumentException("Unable to convert data value of type "
                + dataValue.getClass().getName() + " into a "
                + PGinet.class.getName());

    }

}



public class PGinet extends PGobject implements Serializable, Cloneable {

    private int hashValue;

    /**
     * This constructor takes a string in the inet format a.b.c.d[/netmask] and
     * creates a new PGinet to represent it.
     *
     * @param s The string representation of the inet value.
     * @exception SQLException If the string is invalid.
     */
    public PGinet(String s)
            throws SQLException {
        this();
        this.setValue(s);
    }

    /**
     * A simple constructor.
     */
    public PGinet() {
        setType("inet");
    }

    /**
     * This method sets the value of this PGinet object.
     *
     * @param v A string representation of an inet address a.b.c.d[/netmask]
     * @exception SQLException If the parameter is not a valid inet address.
     */
    @Override
    public void setValue(String v)
            throws SQLException {
        if (v == null) {
            throw (new PSQLException(GT.tr("Conversion to type {0} failed: {1}.",
                    new Object[]{type, v}), PSQLState.DATA_TYPE_MISMATCH));
        }

        PGtokenizer t = new PGtokenizer(v, '/');

        int size = t.getSize();
        if ((size != 1) && (size != 2)) {
            throw (new PSQLException(GT.tr("Conversion to type {0} failed: {1}.",
                    new Object[]{type, v}), PSQLState.DATA_TYPE_MISMATCH));
        }

        int a = 0;
        int b = 0;
        int c = 0;
        int d = 0;
        int netmask = 32;

        try {
            if (size == 2) {
                netmask = Integer.valueOf(t.getToken(1)).intValue();
                if ((netmask < 0) || (netmask > 32)) {
                    throw (new PSQLException(
                            GT.tr("Conversion to typ {0} failed: {1}.", new Object[]{type, v}),
                            PSQLState.DATA_TYPE_MISMATCH));
                }
            }

            t = new PGtokenizer(t.getToken(0), '.');
            if (t.getSize() != 4) {
                throw (new PSQLException(
                        GT.tr("Conversion to typ {0} failed: {1}.", new Object[]{type, v}),
                        PSQLState.DATA_TYPE_MISMATCH));
            }

            a = Integer.valueOf(t.getToken(0)).intValue();
            b = Integer.valueOf(t.getToken(1)).intValue();
            c = Integer.valueOf(t.getToken(2)).intValue();
            d = Integer.valueOf(t.getToken(3)).intValue();
        } catch (NumberFormatException e) {
            throw (new PSQLException(GT.tr("Conversion to type {0} failed: {1}.",
                    new Object[]{type, v}), PSQLState.DATA_TYPE_MISMATCH, e));
        }

        // ensure that the values are within a valid range.
        if ((a < 0) || (a > 255)
                || (b < 0) || (b > 255)
                || (c < 0) || (c > 255)
                || (d < 0) || (d > 255)) {
            throw (new PSQLException(GT.tr("Conversion to type {0} failed: {1}.",
                    new Object[]{type, v}), PSQLState.DATA_TYPE_MISMATCH));
        }

        this.hashValue = ((a ^ c) << 24) | ((b ^ d) << 16) | ((b ^ c) << 8) | (d ^ netmask);
        this.value = "" + a + "." + b + "." + c + "." + d + ((netmask == 32) ? "" : ("/" + netmask));
    }

    /**
     * Get the hash code for this network address.
     *
     * @return The hash value for this object.
     */
    @Override
    public int hashCode() {
        return (this.hashValue);
    }

    /**
     * Compare two PGinet's for equality.
     *
     * @param obj The object which we wish to compare.
     * @return true if it represents the same network or ip address as this
     * PGinet, false otherwise.
     */
    @Override
    public boolean equals(Object obj) {
        if (obj instanceof PGinet) {
            PGinet inet = (PGinet) obj;
            if (this.toString().equals(inet.toString())) {
                return (true);
            }
        }
        return (false);
    }

    /**
     * Make a duplicate of this PGinet object.
     *
     * @return null on failure, or a new PGinet address which is equal to this
     * object.
     */
    @Override
    public Object clone() {
        try {
            return (new PGinet(this.getValue()));
        } catch (SQLException e) {
            return (null);
        }
    }
}


@Entity
public class Test implements Serializable {

    @Id
    private Integer id;

    @Column(columnDefinition = "inet")
    @Convert(converter = PostgresInetConverter.class)
    private InetAddress  address;

    public Test(){
       
    }
   ...
}

CREATE TABLE public.test
(
  id integer,
  address inet,
  CONSTRAINT id PRIMARY KEY (id)
)