// Point3.java import java.sql.*; public class Point3 implements SQLData { String type_name; double x; double y; public Point3 () {} public void readSQL (SQLInput stream, String type_name) throws SQLException { this.type_name = type_name; x = stream.readDouble (); y = stream.readDouble (); } public String getSQLTypeName () throws SQLException { return type_name; } public void writeSQL (SQLOutput stream) throws SQLException { stream.writeDouble (x); stream.writeDouble (y); } public double distance (Point3 p) { return Math.sqrt ((y - p.y) * (y - p.y) + (x - p.x) * (x - p.x)); } public void moveBy (Point3 p) { x += p.x; y += p.y; } }