U fixes the path to the JRE on MacOS if release file not found

Author: fvarrui

src/main/java/io/github/fvarrui/javapackager/utils/FileUtils.java

@@ -211,5 +211,9 @@ public static void downloadFromUrl(URL url, File file) throws IOException {
 	public static boolean exists(File file) {
 		return file != null && file.exists();
 	}
+	
+	public static boolean folderContainsFile(File folder, String filename) {
+		return new File(folder, filename).exists();
+	}
 
 }

src/main/java/io/github/fvarrui/javapackager/utils/JDKUtils.java

@@ -13,7 +13,7 @@
 public class JDKUtils {
 
 	/**
-	 * Converts "release" file from specified JDK to map
+	 * Converts "release" file from specified JDK or JRE to map
 	 * @param jdkPath JDK directory path
 	 * @return Map with all properties
 	 * @throws FileNotFoundException release file not found
@@ -31,6 +31,14 @@ private static Map<String, String> getRelease(File jdkPath) throws FileNotFoundE
 		return propertiesMap;
 	}
 
+	/**
+	 * Checks if the platform specified in the "release" file matches the required platform 
+	 * @param platform
+	 * @param jdkPath
+	 * @return
+	 * @throws FileNotFoundException
+	 * @throws IOException
+	 */
 	private static boolean checkPlatform(Platform platform, File jdkPath) throws FileNotFoundException, IOException {
 		Map<String, String> releaseMap = getRelease(jdkPath);
 		String osName = releaseMap.get("OS_NAME");