ImageCache.java

/*
* Authors: Jerry Li & Victor Jiang
* Date: June 13, 2025
* Description: This class stores and reuses images so the game doesn't have to load them from the disk repeatedly
*/

import java.awt.image.BufferedImage;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import javax.imageio.ImageIO;

/** Utility class that caches loaded images to avoid duplicate disk I/O. */
public final class ImageCache {
    /**
     * Cache of already loaded images. ConcurrentHashMap is used so that the
     * cache can be accessed safely from multiple threads if image loading
     * occurs on different game loops or Swing threads.
     */
    public static final Map<String, BufferedImage> CACHE = new ConcurrentHashMap<>();

    public ImageCache() {}

    /**
     * Loads an image from either the classpath or filesystem. Subsequent calls
     * with the same path return the cached instance.
     */
    public static BufferedImage load(String path) {
        BufferedImage img = CACHE.get(path);
        InputStream in = null;
        InputStream fileIn = null;
        InputStream auto = null;

        if (img != null) {
            return img;
        }
        try {
            in = ImageCache.class.getResourceAsStream(path);
            if (in != null) {
                auto = in;
            } else {
                fileIn = new FileInputStream(new File(path));
                auto = fileIn;
            }
            img = ImageIO.read(auto);
            CACHE.put(path, img);
            return img;
        } catch (IOException e) {
            System.err.println("Error loading image: " + path + " - " + e.getMessage());
            return null;
        } finally {
            if (auto != null) {
                try {
                    auto.close();
                } catch (IOException ignored) {
                }
            }
        }
    }
}