fix(android): run downloadFile asynchronously

Author: ItsChaceD

filesystem/android/src/main/java/com/capacitorjs/plugins/filesystem/Filesystem.java

@@ -3,6 +3,8 @@
 import android.content.Context;
 import android.net.Uri;
 import android.os.Environment;
+import android.os.Handler;
+import android.os.Looper;
 import android.util.Base64;
 import com.capacitorjs.plugins.filesystem.exceptions.CopyFailedException;
 import com.capacitorjs.plugins.filesystem.exceptions.DirectoryExistsException;
@@ -27,6 +29,8 @@
 import java.nio.charset.Charset;
 import java.nio.charset.StandardCharsets;
 import java.util.Locale;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
 import org.json.JSONException;
 
 public class Filesystem {
@@ -303,9 +307,32 @@ public void copyRecursively(File src, File dst) throws IOException {
         }
     }
 
-    public JSObject downloadFile(PluginCall call, Bridge bridge, HttpRequestHandler.ProgressEmitter emitter)
-        throws IOException, URISyntaxException, JSONException {
+    public void downloadFile(
+        PluginCall call,
+        Bridge bridge,
+        HttpRequestHandler.ProgressEmitter emitter,
+        FilesystemDownloadCallback callback
+    ) {
         String urlString = call.getString("url", "");
+        ExecutorService executor = Executors.newSingleThreadExecutor();
+        Handler handler = new Handler(Looper.getMainLooper());
+
+        executor.execute(
+            () -> {
+                try {
+                    JSObject result = doDownloadInBackground(urlString, call, bridge, emitter);
+                    handler.post(() -> callback.onSuccess(result));
+                } catch (Exception error) {
+                    handler.post(() -> callback.onError(error));
+                } finally {
+                    executor.shutdown();
+                }
+            }
+        );
+    }
+
+    private JSObject doDownloadInBackground(String urlString, PluginCall call, Bridge bridge, HttpRequestHandler.ProgressEmitter emitter)
+        throws IOException, URISyntaxException, JSONException {
         JSObject headers = call.getObject("headers", new JSObject());
         JSObject params = call.getObject("params", new JSObject());
         Integer connectTimeout = call.getInt("connectTimeout");
@@ -374,10 +401,14 @@ public JSObject downloadFile(PluginCall call, Bridge bridge, HttpRequestHandler.
         connectionInputStream.close();
         fileOutputStream.close();
 
-        return new JSObject() {
-            {
-                put("path", file.getAbsolutePath());
-            }
-        };
+        JSObject ret = new JSObject();
+        ret.put("path", file.getAbsolutePath());
+        return ret;
+    }
+
+    public interface FilesystemDownloadCallback {
+        void onSuccess(JSObject result);
+
+        void onError(Exception error);
     }
 }

filesystem/android/src/main/java/com/capacitorjs/plugins/filesystem/FilesystemPlugin.java

@@ -388,23 +388,37 @@ public void downloadFile(PluginCall call) {
 
             if (isPublicDirectory(directory) && !isStoragePermissionGranted()) {
                 requestAllPermissions(call, "permissionCallback");
-            } else {
-                HttpRequestHandler.ProgressEmitter emitter = (bytes, contentLength) -> {
-                    JSObject ret = new JSObject();
-                    ret.put("url", call.getString("url"));
-                    ret.put("bytes", bytes);
-                    ret.put("contentLength", contentLength);
+                return;
+            }
 
-                    notifyListeners("progress", ret);
-                };
+            HttpRequestHandler.ProgressEmitter emitter = (bytes, contentLength) -> {
+                JSObject ret = new JSObject();
+                ret.put("url", call.getString("url"));
+                ret.put("bytes", bytes);
+                ret.put("contentLength", contentLength);
+                notifyListeners("progress", ret);
+            };
+
+            implementation.downloadFile(
+                call,
+                bridge,
+                emitter,
+                new Filesystem.FilesystemDownloadCallback() {
+                    @Override
+                    public void onSuccess(JSObject response) {
+                        // update mediaStore index only if file was written to external storage
+                        if (isPublicDirectory(directory)) {
+                            MediaScannerConnection.scanFile(getContext(), new String[] { response.getString("path") }, null, null);
+                        }
+                        call.resolve(response);
+                    }
 
-                JSObject response = implementation.downloadFile(call, bridge, emitter);
-                // update mediaStore index only if file was written to external storage
-                if (isPublicDirectory(directory)) {
-                    MediaScannerConnection.scanFile(getContext(), new String[] { response.getString("path") }, null, null);
+                    @Override
+                    public void onError(Exception error) {
+                        call.reject("Error downloading file: " + error.getLocalizedMessage(), error);
+                    }
                 }
-                call.resolve(response);
-            }
+            );
         } catch (Exception ex) {
             call.reject("Error downloading file: " + ex.getLocalizedMessage(), ex);
         }