Fix Android app connection and timeout issues

Add proper timeout configuration to OkHttpClient (30s connect/read/write)
Update OkHttp logging-interceptor to 4.12.0 to match OkHttp version
Improve error messages to show server URL for debugging
Configure backend to listen on all interfaces (0.0.0.0)
Remove EdgeToEdge calls that interfered with layout

android/app/build.gradle.kts

@@ -39,7 +39,7 @@ dependencies {
 
     implementation("com.squareup.retrofit2:retrofit:2.9.0")
     implementation("com.squareup.retrofit2:converter-gson:2.9.0")
-    implementation("com.squareup.okhttp3:logging-interceptor:4.9.1")
+    implementation("com.squareup.okhttp3:logging-interceptor:4.12.0")
     implementation("com.squareup.okhttp3:okhttp:4.12.0")
 
     implementation("com.google.android.material:material:1.11.0")

android/app/src/main/java/com/example/petstoremobile/activities/HomeActivity.java

@@ -39,15 +39,8 @@ public class HomeActivity extends AppCompatActivity {
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
-        EdgeToEdge.enable(this);
         setContentView(R.layout.activity_home);
 
-        ViewCompat.setOnApplyWindowInsetsListener(findViewById(R.id.main), (v, insets) -> {
-            Insets systemBars = insets.getInsets(WindowInsetsCompat.Type.systemBars());
-            v.setPadding(systemBars.left, systemBars.top, systemBars.right, systemBars.bottom);
-            return insets;
-        });
-
         //get the bottom navbar from the layout
         bottomNav = findViewById(R.id.bottom_navigation);
         

android/app/src/main/java/com/example/petstoremobile/activities/MainActivity.java

@@ -52,15 +52,8 @@ public class MainActivity extends AppCompatActivity {
             }
         }
 
-        EdgeToEdge.enable(this);
         setContentView(R.layout.activity_main);
 
-        ViewCompat.setOnApplyWindowInsetsListener(findViewById(R.id.main), (v, insets) -> {
-            Insets systemBars = insets.getInsets(WindowInsetsCompat.Type.systemBars());
-            v.setPadding(systemBars.left, systemBars.top, systemBars.right, systemBars.bottom);
-            return insets;
-        });
-
         //get all controls from layout
         tvLoginStatus = findViewById(R.id.tvLoginStatus);
         etUser     = findViewById(R.id.etUser);
@@ -132,15 +125,43 @@ public class MainActivity extends AppCompatActivity {
                                     }
                                 });
                     } else {
-                        Toast.makeText(MainActivity.this, "Login failed", Toast.LENGTH_SHORT).show();
-                        tvLoginStatus.setText("Login failed");
+                        String errorMessage;
+                        switch (response.code()) {
+                            case 401:
+                                errorMessage = "Invalid username or password";
+                                break;
+                            case 500:
+                                errorMessage = "Server error. Please try again later.";
+                                break;
+                            case 503:
+                                errorMessage = "Service unavailable. Backend may be starting up.";
+                                break;
+                            default:
+                                errorMessage = "Login failed (Error " + response.code() + ")";
+                        }
+                        Toast.makeText(MainActivity.this, errorMessage, Toast.LENGTH_LONG).show();
+                        tvLoginStatus.setText(errorMessage);
                     }
                 }
 
                 @Override
                 public void onFailure(Call<AuthDTO.LoginResponse> call, Throwable t) {
-                    Toast.makeText(MainActivity.this, "Login failed", Toast.LENGTH_SHORT).show();
-                    tvLoginStatus.setText("Login failed");
+                    Log.e("MainActivity", "Login request failed", t);
+
+                    String errorMessage;
+                    if (t instanceof java.net.ConnectException ||
+                        t instanceof java.net.SocketTimeoutException ||
+                        t instanceof java.net.UnknownHostException) {
+                        errorMessage = "Cannot connect to server at " + RetrofitClient.BASE_URL +
+                                ". Please check if the backend is running.";
+                    } else if (t instanceof java.io.IOException) {
+                        errorMessage = "Network error. Please check your connection.";
+                    } else {
+                        errorMessage = "Login failed: " + t.getMessage();
+                    }
+
+                    Toast.makeText(MainActivity.this, errorMessage, Toast.LENGTH_LONG).show();
+                    tvLoginStatus.setText(errorMessage);
                 }
             });
         });

android/app/src/main/java/com/example/petstoremobile/api/RetrofitClient.java

@@ -11,6 +11,8 @@ import okhttp3.logging.HttpLoggingInterceptor;
 import retrofit2.Retrofit;
 import retrofit2.converter.gson.GsonConverterFactory;
 
+import java.util.concurrent.TimeUnit;
+
 //Retrofit client Used for API calls
 public class RetrofitClient {
     public static final String BASE_URL = getBaseUrl();
@@ -41,6 +43,9 @@ public class RetrofitClient {
         OkHttpClient client = new OkHttpClient.Builder()
                 .addInterceptor(interceptor)
                 .addInterceptor(new AuthInterceptor(context))
+                .connectTimeout(30, TimeUnit.SECONDS)
+                .readTimeout(30, TimeUnit.SECONDS)
+                .writeTimeout(30, TimeUnit.SECONDS)
                 .build();
 
         //build the retrofit object with all needed properties

backend/src/main/resources/application.yml

@@ -36,6 +36,7 @@ spring:
 
 server:
   port: ${SERVER_PORT:8080}
+  address: ${SERVER_ADDRESS:0.0.0.0}
   servlet:
     context-path: /