Clean Code

Listing B-5 (continued)
SpreadsheetDate.java

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386
Appendix B: 
org.jfree.date.SerialDate
249 
250 /**
251 * Tests the equality of this date with an arbitrary object.
252 *
253 * This method will return true ONLY if the object is an instance of the
254 * {@link SerialDate} base class, and it represents the same day as this
255 * {@link SpreadsheetDate}.
256 *
257 * @param object the object to compare (null permitted).
258 *
259 * @return A boolean.
260 */
261 public boolean equals(final Object object) {
262 
263 if (object instanceof SerialDate) {
264 final SerialDate s = (SerialDate) object;
265 return (s.toSerial() == this.toSerial());
266 }
267 else {
268 return false;
269 }
270 
271 }
272 
273 /**
274 * Returns a hash code for this object instance.
275 *
276 * @return A hash code.
277 */
278 public int hashCode() {
279 return toSerial();
280 }
281 
282 /**
283 * Returns the difference (in days) between this date and the specified
284 * 'other' date.
285 *
286 * @param other the date being compared to.
287 *
288 * @return The difference (in days) between this date and the specified
289 * 'other' date.
290 */
291 public int compare(final SerialDate other) {
292 return this.serial - other.toSerial();
293 }
294 
295 /**
296 * Implements the method required by the Comparable interface.
297 *
298 * @param other the other object (usually another SerialDate).
299 *
300 * @return A negative integer, zero, or a positive integer as this object
301 * is less than, equal to, or greater than the specified object.
302 */
303 public int compareTo(final Object other) {
304 return compare((SerialDate) other);
305 }
306 
307 /**
308 * Returns true if this SerialDate represents the same date as the
309 * specified SerialDate.
310 *