Improving structure with inheritance - Objects First with Java: A Practical Introduction Using BlueJ - page 277

Code 8.2
continued
Source code of the
PhotoPost class

private String caption; // a one-line image caption
private long timestamp;
private int likes;
private ArrayList<String> comments;

/**
* Constructor for objects of class PhotoPost.
*
* @param author The username of the author of this post.
* @param filename The filename of the image in this post.
* @param caption A caption for the image.
*/
public PhotoPost(String author, String filename, String caption)
{

username = author;
this .filename = filename;
this .caption = caption;
timestamp = System.currentTimeMillis();
likes = 0;
comments = new ArrayList<String>();

}

/**
* Record one more 'Like' indication from a user.
*/
public void like()
{

likes++;

}

/**
* Record that a user has withdrawn his/her 'Like' vote.
*/
public void unlike()
{

if (likes > 0) {
likes--;

}

}

/**
* Add a comment to this post.
*
* @param text The new comment to add.
*/