Display latest image

The latest image gets displayed for 60 seconds, after that all images
get displayed randomly.

src/net/molez/mandlm/fotostream/server/CurrentImageURLServiceImpl.java

@@ -1,6 +1,10 @@
 package net.molez.mandlm.fotostream.server;
 
 import java.io.File;
+import java.util.ArrayList;
+import java.util.Comparator;
+import java.util.Date;
+import java.util.List;
 import java.util.Random;
 
 import com.google.gwt.user.server.rpc.RemoteServiceServlet;
@@ -10,12 +14,52 @@ import net.molez.mandlm.fotostream.client.CurrentImageURLService;
 @SuppressWarnings("serial")
 public class CurrentImageURLServiceImpl extends RemoteServiceServlet implements CurrentImageURLService 
 {
+	private List<File> imageFiles = new ArrayList<File>();
+	
+	private void readImageFiles()
+	{
+		imageFiles.clear();
+		
+		File imageFolder = new File("img/");
+		File[] files = imageFolder.listFiles();
+		
+		for (File imageFile : files)
+		{
+			if (imageFile.isFile() && imageFile.getName().endsWith(".jpg"))
+			{
+				imageFiles.add(imageFile);
+			}
+		}
+		
+		imageFiles.sort(new Comparator<File>()
+		{
+			@Override
+			public int compare(File file0, File file1) 
+			{
+				Long file0Date = file0.lastModified();
+				Long file1Date = file1.lastModified();
+				
+				return file0Date.compareTo(file1Date);
+			}
+		});		
+	}
+	
 	public String getCurrentImageURL() 
 	{
-		File imageFolder = new File("img/");
+		int newImageSeconds = 60;
 		
-		File[] fileList = imageFolder.listFiles();
+		readImageFiles();
 		
-		return fileList[new Random().nextInt(fileList.length)].getPath();
+		File latestFile = imageFiles.get(imageFiles.size() - 1);
+		Date latestFileDate = new Date(latestFile.lastModified());
+		
+		if (latestFileDate.before(new Date(new Date().getTime() - newImageSeconds * 1000)))
+		{
+			return imageFiles.get(new Random().nextInt(imageFiles.size())).getPath();
+		}
+		else
+		{
+			return latestFile.getPath();
+		}
 	}
 }

war/FotoStream.css

@@ -3,4 +3,5 @@ div
 {
 	padding: 20px;
 	background-color: black;
+	color: green;
 }