[url_launcher] Fix Android Java warnings (#3690)

[url_launcher] Fix Android Java warnings

Author: stuartmorgan-g

packages/url_launcher/url_launcher_android/CHANGELOG.md

@@ -1,5 +1,6 @@
-## NEXT
+## 6.0.27
 
+* Fixes Java warnings.
 * Updates minimum Flutter version to 3.3.
 
 ## 6.0.26

packages/url_launcher/url_launcher_android/android/build.gradle

@@ -32,7 +32,6 @@ android {
         checkAllWarnings true
         warningsAsErrors true
         disable 'AndroidGradlePluginVersion', 'InvalidPackage', 'GradleDependency'
-        baseline file("lint-baseline.xml")
     }
 
 

packages/url_launcher/url_launcher_android/android/lint-baseline.xml

@@ -6,6 +6,7 @@
 
 import android.os.Bundle;
 import android.util.Log;
+import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 import io.flutter.plugin.common.BinaryMessenger;
 import io.flutter.plugin.common.MethodCall;
@@ -30,7 +31,7 @@ final class MethodCallHandlerImpl implements MethodCallHandler {
   }
 
   @Override
-  public void onMethodCall(MethodCall call, Result result) {
+  public void onMethodCall(@NonNull MethodCall call, @NonNull Result result) {
     final String url = call.argument("url");
     switch (call.method) {
       case "canLaunch":
@@ -80,11 +81,11 @@ void stopListening() {
     channel = null;
   }
 
-  private void onCanLaunch(Result result, String url) {
+  private void onCanLaunch(@NonNull Result result, @NonNull String url) {
     result.success(urlLauncher.canLaunch(url));
   }
 
-  private void onLaunch(MethodCall call, Result result, String url) {
+  private void onLaunch(@NonNull MethodCall call, @NonNull Result result, @NonNull String url) {
     final boolean useWebView = call.argument("useWebView");
     final boolean enableJavaScript = call.argument("enableJavaScript");
     final boolean enableDomStorage = call.argument("enableDomStorage");
@@ -111,7 +112,7 @@ private void onCloseWebView(Result result) {
     result.success(null);
   }
 
-  private static Bundle extractBundle(Map<String, String> headersMap) {
+  private static @NonNull Bundle extractBundle(Map<String, String> headersMap) {
     final Bundle headersBundle = new Bundle();
     for (String key : headersMap.keySet()) {
       final String value = headersMap.get(key);

packages/url_launcher/url_launcher_android/android/src/main/java/io/flutter/plugins/urllauncher/MethodCallHandlerImpl.java

@@ -13,6 +13,7 @@
 import android.os.Bundle;
 import android.provider.Browser;
 import android.util.Log;
+import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 
 /** Launches components for URLs. */
@@ -37,7 +38,7 @@ void setActivity(@Nullable Activity activity) {
   }
 
   /** Returns whether the given {@code url} resolves into an existing component. */
-  boolean canLaunch(String url) {
+  boolean canLaunch(@NonNull String url) {
     Intent launchIntent = new Intent(Intent.ACTION_VIEW);
     launchIntent.setData(Uri.parse(url));
     ComponentName componentName =
@@ -65,8 +66,8 @@ boolean canLaunch(String url) {
    *     launchIntent}. {@link LaunchStatus#OK} otherwise.
    */
   LaunchStatus launch(
-      String url,
-      Bundle headersBundle,
+      @NonNull String url,
+      @NonNull Bundle headersBundle,
       boolean useWebView,
       boolean enableJavaScript,
       boolean enableDomStorage) {

packages/url_launcher/url_launcher_android/android/src/main/java/io/flutter/plugins/urllauncher/UrlLauncher.java

@@ -29,7 +29,8 @@ public final class UrlLauncherPlugin implements FlutterPlugin, ActivityAware {
    * won't react to changes in activity or context, unlike {@link UrlLauncherPlugin}.
    */
   @SuppressWarnings("deprecation")
-  public static void registerWith(io.flutter.plugin.common.PluginRegistry.Registrar registrar) {
+  public static void registerWith(
+      @NonNull io.flutter.plugin.common.PluginRegistry.Registrar registrar) {
     MethodCallHandlerImpl handler =
         new MethodCallHandlerImpl(new UrlLauncher(registrar.context(), registrar.activity()));
     handler.startListening(registrar.messenger());
@@ -61,6 +62,7 @@ public void onAttachedToActivity(@NonNull ActivityPluginBinding binding) {
       return;
     }
 
+    assert urlLauncher != null;
     urlLauncher.setActivity(binding.getActivity());
   }
 
@@ -71,6 +73,7 @@ public void onDetachedFromActivity() {
       return;
     }
 
+    assert urlLauncher != null;
     urlLauncher.setActivity(null);
   }
 

packages/url_launcher/url_launcher_android/android/src/main/java/io/flutter/plugins/urllauncher/UrlLauncherPlugin.java

@@ -34,7 +34,7 @@ public class WebViewActivity extends Activity {
    * Use this to trigger a BroadcastReceiver inside WebViewActivity
    * that will request the current instance to finish.
    * */
-  public static String ACTION_CLOSE = "close action";
+  public static final String ACTION_CLOSE = "close action";
 
   private final BroadcastReceiver broadcastReceiver =
       new BroadcastReceiver() {
@@ -74,12 +74,13 @@ public boolean shouldOverrideUrlLoading(WebView view, WebResourceRequest request
         }
       };
 
-  private WebView webview;
+  // Uses default (package-private) access since it's used by inner class implementations.
+  WebView webview;
 
-  private IntentFilter closeIntentFilter = new IntentFilter(ACTION_CLOSE);
+  private final IntentFilter closeIntentFilter = new IntentFilter(ACTION_CLOSE);
 
   // Verifies that a url opened by `Window.open` has a secure url.
-  private class FlutterWebChromeClient extends WebChromeClient {
+  class FlutterWebChromeClient extends WebChromeClient {
     @Override
     public boolean onCreateWindow(
         final WebView view, boolean isDialog, boolean isUserGesture, Message resultMsg) {
@@ -117,7 +118,7 @@ public boolean shouldOverrideUrlLoading(WebView view, String url) {
   }
 
   @Override
-  public void onCreate(Bundle savedInstanceState) {
+  public void onCreate(@Nullable Bundle savedInstanceState) {
     super.onCreate(savedInstanceState);
     webview = new WebView(this);
     setContentView(webview);
@@ -146,7 +147,7 @@ public void onCreate(Bundle savedInstanceState) {
   }
 
   @VisibleForTesting
-  public static Map<String, String> extractHeaders(@Nullable Bundle headersBundle) {
+  public static @NonNull Map<String, String> extractHeaders(@Nullable Bundle headersBundle) {
     if (headersBundle == null) {
       return Collections.emptyMap();
     }
@@ -165,25 +166,25 @@ protected void onDestroy() {
   }
 
   @Override
-  public boolean onKeyDown(int keyCode, KeyEvent event) {
+  public boolean onKeyDown(int keyCode, @Nullable KeyEvent event) {
     if (keyCode == KeyEvent.KEYCODE_BACK && webview.canGoBack()) {
       webview.goBack();
       return true;
     }
     return super.onKeyDown(keyCode, event);
   }
 
-  private static String URL_EXTRA = "url";
-  private static String ENABLE_JS_EXTRA = "enableJavaScript";
-  private static String ENABLE_DOM_EXTRA = "enableDomStorage";
+  private static final String URL_EXTRA = "url";
+  private static final String ENABLE_JS_EXTRA = "enableJavaScript";
+  private static final String ENABLE_DOM_EXTRA = "enableDomStorage";
 
   /* Hides the constants used to forward data to the Activity instance. */
-  public static Intent createIntent(
-      Context context,
-      String url,
+  public static @NonNull Intent createIntent(
+      @NonNull Context context,
+      @NonNull String url,
       boolean enableJavaScript,
       boolean enableDomStorage,
-      Bundle headersBundle) {
+      @NonNull Bundle headersBundle) {
     return new Intent(context, WebViewActivity.class)
         .putExtra(URL_EXTRA, url)
         .putExtra(ENABLE_JS_EXTRA, enableJavaScript)

packages/url_launcher/url_launcher_android/android/src/main/java/io/flutter/plugins/urllauncher/WebViewActivity.java

@@ -2,7 +2,7 @@ name: url_launcher_android
 description: Android implementation of the url_launcher plugin.
 repository: https://github.com/flutter/packages/tree/main/packages/url_launcher/url_launcher_android
 issue_tracker: https://github.com/flutter/flutter/issues?q=is%3Aissue+is%3Aopen+label%3A%22p%3A+url_launcher%22
-version: 6.0.26
+version: 6.0.27
 
 environment:
   sdk: ">=2.18.0 <4.0.0"