Fixes crash when an image is not found.

Adds an image_not_found.png
Displays this Image as when the path is not valid.

src/utility/ImageImport.java

@@ -2,6 +2,8 @@ package utility;
 
 import java.awt.Image;
 import java.awt.image.BufferedImage;
+import java.awt.image.ColorModel;
+import java.awt.image.WritableRaster;
 import java.io.File;
 import java.io.FileInputStream;
 import java.io.FileNotFoundException;
@@ -12,59 +14,35 @@ import javax.imageio.ImageIO;
 
 /**
  * 
- * @author TU-Darmstadt BP Gruppe 7 WS17/18
- *	Centralized resource loading methods
- *	for improved performance and easier troubleshooting.
+ * @author TU-Darmstadt BP Gruppe 7 WS17/18 Centralized resource loading methods
+ *         for improved performance and easier troubleshooting.
  */
 public class ImageImport {
-	
-	/**
-	 * 30x30 pixel FileNotFound Icon, which can be shown without using I/O operations
-	 * a red cross.
-	 */
-	static private BufferedImage defaultImage;
 	/*
-	 * Save nothing: Reload every image whenever requested.
-	 * Save external: Only save images that were found as external file.
-	 * Save raw: Save all non-scaled images.
-	 * Save everything: self-explanatory.
+	 * Save nothing: Reload every image whenever requested. Save external: Only save
+	 * images that were found as external file. Save raw: Save all non-scaled
+	 * images. Save everything: self-explanatory.
 	 */
 	private static HashMap<String, Image> imgStorage;
-	private static ImageImport xmp=new ImageImport();//Used to load resources from the JAR.
-	
-	static{
-		/*
-		 * creates the default Image 
-		 */
-		defaultImage = new BufferedImage(30,30,BufferedImage.TYPE_BYTE_INDEXED);
-		for(int x = 0; x < 30; x++)
-			for(int y = 0; y < 30; y++){
-				if(x == 29 || y == 29)
-					//Border Bottom/Left -> Light Grey
-					(defaultImage).setRGB(x, y, 13158600);
-				else if(x == 0 || y == 0)
-					//Border Top/Right -> Dark Grey
-					(defaultImage).setRGB(x, y, 6316128);
-				else if((x == y || x == 31 - y) && 6 < x && x < 25)
-					//Red Cross in the middle
-					(defaultImage).setRGB(x, y, 13107200);
-				else //all other Pixels are white
-					(defaultImage).setRGB(x, y, 16777215);
-			}
-		imgStorage=new HashMap<String, Image>();
+	private static ImageImport xmp = new ImageImport();// Used to load resources from the JAR.
+
+	static {
+		imgStorage = new HashMap<String, Image>();
 	}
-	
+
 	/**
 	 * The rawest function replacing the old method without any default parameters.
-	 * Currently not used in HOLEG at all(aside form calls from the convenience methods).
-	 * @param url Path to the image to be loaded.
-	 * @param w Width the loaded image should be scaled to.
-	 * @param h Height the loaded image should be scaled to.
-	 * @param hints Hints for the scaling algorithm to be used.
-	 * Same as the parameter in the getScaledInstance function of Image.
+	 * Currently not used in HOLEG at all(aside form calls from the convenience
+	 * methods).
+	 * 
+	 * @param url   Path to the image to be loaded.
+	 * @param w     Width the loaded image should be scaled to.
+	 * @param h     Height the loaded image should be scaled to.
+	 * @param hints Hints for the scaling algorithm to be used. Same as the
+	 *              parameter in the getScaledInstance function of Image.
 	 * @return A loaded and scaled image from the requested path.
 	 */
-	static Image loadImage(String url, int w, int h, int hints){
+	static Image loadImage(String url, int w, int h, int hints) {
 		String key = url + "?" + w + "?" + h + "?" + hints;
 		if (imgStorage.containsKey(key))
 			return (imgStorage.get(key));
@@ -74,26 +52,28 @@ public class ImageImport {
 			return img;
 		}
 	}
-	
+
 	/**
 	 * Loads an image from the given path and scales it using the smooth algorithm.
+	 * 
 	 * @param url Path to the image to be loaded.
-	 * @param w Width the loaded image should be scaled to.
-	 * @param h Height the loaded image should be scaled to.
+	 * @param w   Width the loaded image should be scaled to.
+	 * @param h   Height the loaded image should be scaled to.
 	 * @return A loaded and (smoothly) scaled image from the requested path.
 	 */
-	public static Image loadImage(String url, int w, int h){
-		return loadImage(url,w,h, Image.SCALE_SMOOTH);
+	public static Image loadImage(String url, int w, int h) {
+		return loadImage(url, w, h, Image.SCALE_SMOOTH);
 	}
-	
+
 	/**
 	 * Loads an image from the given path and scales it using the smooth algorithm.
+	 * 
 	 * @param url Path to the image to be loaded.
-	 * @param w Width the loaded image should be scaled to.
-	 * @param h Height the loaded image should be scaled to.
+	 * @param w   Width the loaded image should be scaled to.
+	 * @param h   Height the loaded image should be scaled to.
 	 * @return An image loaded from the requested path.
 	 */
-	public static Image loadImage(String url){
+	public static Image loadImage(String url) {
 		if (imgStorage.containsKey(url))
 			return imgStorage.get(url);
 		else {
@@ -101,41 +81,48 @@ public class ImageImport {
 			try {
 				img = ImageIO.read(loadStream(url));
 			} catch (IOException e) {
-				e.printStackTrace();
-				return defaultImage;
+				System.err.println(e);
+				return null;
 			}
 			imgStorage.put(url, img);
 			return img;
 		}
 	}
-	
+
 	/**
-	 * Loads any resource with a given path,
-	 * regardless of whether it is inside the jar or an external resource.
-	 * Every loadImage() function uses this as a basis.
+	 * Loads any resource with a given path, regardless of whether it is inside the
+	 * jar or an external resource. Every loadImage() function uses this as a basis.
+	 * 
 	 * @param url The path (and file name) of the requested resource.
 	 * @return An InputStream from the requested resource.
+	 * @throws FileNotFoundException
 	 */
-	public static InputStream loadStream(String url){
-		InputStream o=xmp.getClass().getResourceAsStream(url);
-		if(o!=null)return o;
-		else{
-			boolean rootSymbol=false;	//Whether url starts with a / or \
-			switch(url.charAt(0)){		//So we can make sure to construct res/path correctly.
-			case '/':case '\\':rootSymbol=true;
+	public static InputStream loadStream(String url) throws FileNotFoundException {
+		InputStream o = xmp.getClass().getResourceAsStream(url);
+		if (o != null)
+			return o;
+		else {
+			boolean rootSymbol = false; // Whether url starts with a / or \
+			switch (url.charAt(0)) { // So we can make sure to construct res/path correctly.
+			case '/':
+			case '\\':
+				rootSymbol = true;
 			}
-			try {
-				//Mixed separators might cause problems. Will fix later.
-				File f=new File(url);//Possible bug with duplicate names.
-				if(!f.exists())url="res"+(rootSymbol?"":"/")+url;
-				return new FileInputStream(url);
-			} catch (FileNotFoundException e1) {
-				e1.printStackTrace();
+			File f = new File(url);
+			if (!f.exists()) {
+				url = "res" + (rootSymbol ? "" : "/") + url;
+			}
+			f = new File(url);// Possible bug with duplicate names.
+			if (!f.exists()) {
+				url = "res/Images/image_not_found.png";
 			}
-			return null;
+			return new FileInputStream(url);
+
 		}
 	}
-	
-	//Nobody needs an instance of this. I do, because I use it to load images from inside the JAR.
-	private ImageImport(){}
+
+	// Nobody needs an instance of this. I do, because I use it to load images from
+	// inside the JAR.
+	private ImageImport() {
+	}
 }