pgcircle.java

关系型数据库 Postgresql 6.5.2

package postgresql.geometric;

import java.io.*;
import java.sql.*;
import postgresql.util.*;

/**
 * This represents postgresql's circle datatype, consisting of a point and
 * a radius
 */
public class PGcircle extends PGobject implements Serializable,Cloneable
{
  /**
   * This is the centre point
   */
  public PGpoint center;
  
  /**
   * This is the radius
   */
  double radius;
  
  /**
   * @param x coordinate of centre
   * @param y coordinate of centre
   * @param r radius of circle
   */
  public PGcircle(double x,double y,double r)
  {
    this(new PGpoint(x,y),r);
  }
  
  /**
   * @param c PGpoint describing the circle's centre
   * @param r radius of circle
   */
  public PGcircle(PGpoint c,double r)
  {
    this();
    this.center = c;
    this.radius = r;
  }
  
  /**
   * @param s definition of the circle in PostgreSQL's syntax.
   * @exception SQLException on conversion failure
   */
  public PGcircle(String s) throws SQLException
  {
    this();
    setValue(s);
  }
  
  /**
   * This constructor is used by the driver.
   */
  public PGcircle()
  {
    setType("circle");
  }
  
  /**
   * @param s definition of the circle in PostgreSQL's syntax.
   * @exception SQLException on conversion failure
   */
  public void setValue(String s) throws SQLException
  {
    PGtokenizer t = new PGtokenizer(PGtokenizer.removeAngle(s),',');
    if(t.getSize() != 2)
      throw new PSQLException("postgresql.geo.circle",s);
    
    try {
      center = new PGpoint(t.getToken(0));
      radius = Double.valueOf(t.getToken(1)).doubleValue();
    } catch(NumberFormatException e) {
      throw new PSQLException("postgresql.geo.circle",e);
    }
  }
  
  /**
   * @param obj Object to compare with
   * @return true if the two boxes are identical
   */
  public boolean equals(Object obj)
  {
    if(obj instanceof PGcircle) {
      PGcircle p = (PGcircle)obj;
      return p.center.equals(center) && p.radius==radius;
    }
    return false;
  }
  
  /**
   * This must be overidden to allow the object to be cloned
   */
  public Object clone()
  {
    return new PGcircle((PGpoint)center.clone(),radius);
  }
  
  /**
   * @return the PGcircle in the syntax expected by postgresql
   */
  public String getValue()
  {
    return "<"+center+","+radius+">";
  }
}