no crash when no versions dir found

README.md

@@ -57,6 +57,28 @@ You will find modpack/mod name with some numbers after it. That is totally inten
 
 Installing a modpack will also generate a profile. However, the profile doesn't use the correct mod loader. Please install the mod loader yourself as instructed.
 
+## Compiling
+To compile the program yourself, some libraries are needed:
+- [Apache Commons IO](https://commons.apache.org/proper/commons-io/)
+- [jansi](https://github.com/fusesource/jansi)
+- [JSON Simple](https://code.google.com/archive/p/json-simple)
+
+Download them and put them somewhere.
+
+This program is compiled with IntelliJ, so I don't know how to compile it outside of IntelliJ.  
+Anyway, follow the steps:
+1. Download the repository by `git clone` or downloading as ZIP and extract it. 
+2. Launch IntelliJ IDEA if you haven't.
+3. Open the directory where the files are extracted into.
+4. In the top bar, go to File->Project Structure.
+5. On the left side, go to Global Libraries.
+6. Click the + symbol and choose Java.
+7. In the file chooser, choose the Java libraries you downloaded.
+8. Click OK on everything.
+9. In the top bar, go to Build->Build Artifacts.
+10. In the little window, choose Build.
+11. The `.jar` file should be built inside `out/artifacts`.
+
 ## Support
 If you want to support me, please consider becoming [my Patron](https://www.patreon.com/nww).
 

src/ml/northwestwind/Constants.java

@@ -6,7 +6,7 @@
 
 public class Constants {
     public static final String CURSEFORGE_API = "https://northwestwind.ml/api/curseforge/mods/";
-    public static final String VERSION = "1.4.0";
+    public static final String VERSION = "1.4.1";
     private static final String OS = System.getProperty("os.name").toLowerCase();
     public static final boolean IS_WINDOWS = (OS.contains("win"));
     public static final boolean IS_MAC = (OS.contains("mac"));

src/ml/northwestwind/Modpack.java

@@ -199,18 +199,28 @@ private static String getModVersion(JSONObject manifest) {
                     String[] splitted = id.split("-");
                     String loader = splitted[0].toLowerCase();
                     String modVer = Arrays.stream(splitted).skip(1).collect(Collectors.joining("-"));
-                    List<String> versions = Arrays.stream(new File(Utils.getMinecraftPath() + File.separator + "versions").listFiles()).map(File::getName).collect(Collectors.toList());
-                    Optional<String> found = versions.stream().filter(name -> name.contains(loader) && name.contains(modVer) && name.contains(version)).findFirst();
-                    if (found.isPresent()) return found.get();
+                    File versionsDir = new File(Utils.getMinecraftPath() + File.separator + "versions");
+                    if (versionsDir.exists()) {
+                        System.out.println(Ansi.ansi().fg(Ansi.Color.MAGENTA).a("Looking into versions directory: ").a(versionsDir.getAbsolutePath()).reset());
+                        String[] versionNames = versionsDir.list();
+                        if (versionNames != null) {
+                            Optional<String> found = Arrays.stream(versionNames).filter(name -> name.contains(loader) && name.contains(modVer) && name.contains(version)).findFirst();
+                            if (found.isPresent()) return found.get();
+                        }
+                    }
                     System.out.println(Ansi.ansi().fg(Ansi.Color.YELLOW).a("We couldn't find the mod launcher version required for your modpack!"));
                     System.out.println(Ansi.ansi().a("Please download the required mod launcher version from the link below. Enter y after you have that installed, or enter n to skip it for now [y/n]"));
                     if (loader.equalsIgnoreCase("forge")) System.out.println(Ansi.ansi().a("https://files.minecraftforge.net/net/minecraftforge/forge/").reset());
                     else if (loader.equalsIgnoreCase("fabric")) System.out.println((Ansi.ansi().a("https://fabricmc.net/use/installer/")).reset());
                     else if (loader.equalsIgnoreCase("quilt")) System.out.println(Ansi.ansi().a("https://quiltmc.org/en/install/").reset());
                     if (Utils.readYesNo()) {
-                        versions = Arrays.stream(new File(Utils.getMinecraftPath() + File.separator + "versions").listFiles()).map(f -> f.getName().toLowerCase()).collect(Collectors.toList());
-                        found = versions.stream().filter(name -> name.contains(loader) && name.contains(modVer) && name.contains(version)).findFirst();
-                        if (found.isPresent()) return found.get();
+                        if (versionsDir.exists()) {
+                            String[] versionNames = versionsDir.list();
+                            if (versionNames != null) {
+                                Optional<String> found = Arrays.stream(versionNames).filter(name -> name.contains(loader) && name.contains(modVer) && name.contains(version)).findFirst();
+                                if (found.isPresent()) return found.get();
+                            }
+                        }
                         System.out.println(Ansi.ansi().fg(Ansi.Color.YELLOW).a("We still couldn't find the mod launcher version required! The installation will continue anyway. You may have to change the profile settings after this."));
                     }
                     if (loader.equalsIgnoreCase("forge")) id = version + "-forge-" + modVer;

update.json

@@ -1,4 +1,7 @@
 {
+  "1.4.1": {
+    "title": "Prevent crashing when no versions directory is found"
+  },
   "1.4.0": {
     "title": "Quilt support"
   },
@@ -83,5 +86,5 @@
   "1.2.0": {
     "title": "Update Checker & Profile Generator"
   },
-  "latest": "1.4.0"
+  "latest": "1.4.1"
 }