Merge pull request #2872 from wordpress-mobile/analysis/add-missing-n…

…ullability-annotations-to-discovery-clients

[Nullability Annotations to Java Classes] Add Missing Nullability Annotations to `Discovery` Network Client Classes (`safe`)

libs/fluxc/src/main/java/org/wordpress/android/fluxc/network/discovery/DiscoveryRequest.java

@@ -15,20 +15,24 @@ public class DiscoveryRequest extends BaseRequest<String> {
     private static final String PROTOCOL_CHARSET = "utf-8";
     private static final String PROTOCOL_CONTENT_TYPE = String.format("text/xml; charset=%s", PROTOCOL_CHARSET);
 
-    private final Listener<String> mListener;
+    @NonNull private final Listener<String> mListener;
 
-    public DiscoveryRequest(String url, Listener<String> listener, BaseErrorListener errorListener) {
+    public DiscoveryRequest(
+            @NonNull String url,
+            @NonNull Listener<String> listener,
+            @NonNull BaseErrorListener errorListener) {
         super(Method.GET, url, errorListener);
         mListener = listener;
     }
 
     @Override
-    protected void deliverResponse(String response) {
+    protected void deliverResponse(@NonNull String response) {
         mListener.onResponse(response);
     }
 
+    @NonNull
     @Override
-    protected Response<String> parseNetworkResponse(NetworkResponse response) {
+    protected Response<String> parseNetworkResponse(@NonNull NetworkResponse response) {
         String parsed;
         try {
             parsed = new String(response.data, HttpHeaderParser.parseCharset(response.headers));
@@ -38,12 +42,14 @@ protected Response<String> parseNetworkResponse(NetworkResponse response) {
         return Response.success(parsed, HttpHeaderParser.parseCacheHeaders(response));
     }
 
+    @NonNull
     @Override
     public BaseNetworkError deliverBaseNetworkError(@NonNull BaseNetworkError error) {
         // no op
         return error;
     }
 
+    @NonNull
     @Override
     public String getBodyContentType() {
         return PROTOCOL_CONTENT_TYPE;

libs/fluxc/src/main/java/org/wordpress/android/fluxc/network/discovery/DiscoveryUtils.java

@@ -3,6 +3,9 @@
 import android.text.TextUtils;
 import android.webkit.URLUtil;
 
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+
 import org.wordpress.android.util.AppLog;
 
 import java.util.regex.Matcher;
@@ -12,7 +15,8 @@ public class DiscoveryUtils {
     /**
      * Strip known unnecessary paths from XML-RPC URL and remove trailing slashes
      */
-    public static String stripKnownPaths(String url) {
+    @NonNull
+    public static String stripKnownPaths(@NonNull String url) {
         // Remove 'wp-login.php' if available in the URL
         String sanitizedURL = truncateUrl(url, "wp-login.php");
 
@@ -36,9 +40,10 @@ public static String stripKnownPaths(String url) {
      * Truncate a string beginning at the marker
      * @param url input string
      * @param marker the marker to begin the truncation from
-     * @return new string truncated to the begining of the marker or the input string if marker is not found
+     * @return new string truncated to the beginning of the marker or the input string if marker is not found
      */
-    public static String truncateUrl(String url, String marker) {
+    @NonNull
+    public static String truncateUrl(@NonNull String url, @NonNull String marker) {
         if (TextUtils.isEmpty(marker) || !url.contains(marker)) {
             return url;
         }
@@ -51,7 +56,8 @@ public static String truncateUrl(String url, String marker) {
     /**
      * Append 'xmlrpc.php' if missing in the URL
      */
-    public static String appendXMLRPCPath(String url) {
+    @NonNull
+    public static String appendXMLRPCPath(@NonNull String url) {
         // Don't use 'ends' here! Some hosting wants parameters passed to baseURL/xmlrpc-php?my-authcode=XXX
         if (url.contains("xmlrpc.php")) {
             return url;
@@ -63,7 +69,7 @@ public static String appendXMLRPCPath(String url) {
     /**
      * Verify that the response of system.listMethods matches the expected list of available XML-RPC methods
      */
-    public static boolean validateListMethodsResponse(Object[] availableMethods) {
+    public static boolean validateListMethodsResponse(@Nullable Object[] availableMethods) {
         if (availableMethods == null) {
             AppLog.e(AppLog.T.NUX, "The response of system.listMethods was empty!");
             return false;
@@ -96,7 +102,7 @@ public static boolean validateListMethodsResponse(Object[] availableMethods) {
     /**
      * Check whether given network error is a 401 Unauthorized HTTP error
      */
-    public static boolean isHTTPAuthErrorMessage(Exception e) {
+    public static boolean isHTTPAuthErrorMessage(@Nullable Exception e) {
         return e != null && e.getMessage() != null && e.getMessage().contains("401");
     }
 
@@ -105,7 +111,8 @@ public static boolean isHTTPAuthErrorMessage(Exception e) {
      *
      * @return XML-RPC endpoint for the specified site, or null if unable to discover endpoint.
      */
-    public static String getXMLRPCApiLink(String html) {
+    @Nullable
+    public static String getXMLRPCApiLink(@Nullable String html) {
         Pattern xmlrpcLink = Pattern.compile("<api\\s*?name=\"WordPress\".*?apiLink=\"(.*?)\"",
                 Pattern.CASE_INSENSITIVE | Pattern.DOTALL);
         if (html != null) {
@@ -122,7 +129,8 @@ public static String getXMLRPCApiLink(String html) {
      *
      * @return String XML-RPC url
      */
-    public static String getXMLRPCPingback(String html) {
+    @Nullable
+    public static String getXMLRPCPingback(@Nullable String html) {
         Pattern pingbackLink = Pattern.compile(
                 "<link\\s*?rel=\"pingback\"\\s*?href=\"(.*?)\"",
                 Pattern.CASE_INSENSITIVE | Pattern.DOTALL);

libs/fluxc/src/main/java/org/wordpress/android/fluxc/network/discovery/DiscoveryWPAPIRestClient.java

@@ -1,5 +1,8 @@
 package org.wordpress.android.fluxc.network.discovery;
 
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+
 import com.android.volley.Request;
 import com.android.volley.RequestQueue;
 
@@ -11,6 +14,7 @@
 import org.wordpress.android.fluxc.network.rest.wpapi.WPAPIGsonRequest;
 import org.wordpress.android.util.AppLog;
 
+import java.util.List;
 import java.util.concurrent.ExecutionException;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.TimeoutException;
@@ -21,15 +25,18 @@
 
 import static org.wordpress.android.fluxc.network.discovery.SelfHostedEndpointFinder.TIMEOUT_MS;
 
+@SuppressWarnings("CommentedOutCode")
 @Singleton
 public class DiscoveryWPAPIRestClient extends BaseWPAPIRestClient {
-    @Inject public DiscoveryWPAPIRestClient(Dispatcher dispatcher,
-                                    @Named("custom-ssl") RequestQueue requestQueue,
-                                    UserAgent userAgent) {
+    @Inject public DiscoveryWPAPIRestClient(
+            Dispatcher dispatcher,
+            @Named("custom-ssl") RequestQueue requestQueue,
+            UserAgent userAgent) {
         super(dispatcher, requestQueue, userAgent);
     }
 
-    public String discoverWPAPIBaseURL(String url) throws SelfHostedEndpointFinder.DiscoveryException {
+    @Nullable
+    public String discoverWPAPIBaseURL(@NonNull String url) {
         BaseRequestFuture<String> future = BaseRequestFuture.newFuture();
         WPAPIHeadRequest request = new WPAPIHeadRequest(url, future, future);
         add(request);
@@ -50,18 +57,27 @@ public String discoverWPAPIBaseURL(String url) throws SelfHostedEndpointFinder.D
         return null;
     }
 
-    public String verifyWPAPIV2Support(String wpApiBaseUrl) {
+    @Nullable
+    public String verifyWPAPIV2Support(@NonNull String wpApiBaseUrl) {
         BaseRequestFuture<RootWPAPIRestResponse> future = BaseRequestFuture.newFuture();
         OnWPAPIErrorListener errorListener = future::onErrorResponse;
 
-        WPAPIGsonRequest request = new WPAPIGsonRequest<>(Request.Method.GET, wpApiBaseUrl, null, null,
-                RootWPAPIRestResponse.class, future, errorListener);
+        WPAPIGsonRequest<RootWPAPIRestResponse> request = new WPAPIGsonRequest<>(
+                Request.Method.GET,
+                wpApiBaseUrl,
+                null,
+                null,
+                RootWPAPIRestResponse.class,
+                future,
+                errorListener
+        );
         add(request);
         try {
             RootWPAPIRestResponse response = future.get(TIMEOUT_MS, TimeUnit.MILLISECONDS);
-            if (!response.getNamespaces().contains("wp/v2")) {
+            List<String> namespaces = response.getNamespaces();
+            if (namespaces != null && !namespaces.contains("wp/v2")) {
                 AppLog.i(AppLog.T.NUX, "Site does not have the full WP-API available "
-                        + "(missing wp/v2 namespace)");
+                                       + "(missing wp/v2 namespace)");
                 return null;
             } else {
                 AppLog.i(AppLog.T.NUX, "Found valid WP-API endpoint! - " + wpApiBaseUrl);

libs/fluxc/src/main/java/org/wordpress/android/fluxc/network/discovery/DiscoveryXMLRPCClient.java

@@ -1,5 +1,8 @@
 package org.wordpress.android.fluxc.network.discovery;
 
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+
 import com.android.volley.AuthFailureError;
 import com.android.volley.NetworkResponse;
 import com.android.volley.NoConnectionError;
@@ -31,17 +34,19 @@
 
 @Singleton
 public class DiscoveryXMLRPCClient extends BaseXMLRPCClient {
-    @Inject public DiscoveryXMLRPCClient(Dispatcher dispatcher,
-                                 @Named("custom-ssl") RequestQueue requestQueue,
-                                 UserAgent userAgent,
-                                 HTTPAuthManager httpAuthManager) {
+    @Inject public DiscoveryXMLRPCClient(
+            Dispatcher dispatcher,
+            @Named("custom-ssl") RequestQueue requestQueue,
+            UserAgent userAgent,
+            HTTPAuthManager httpAuthManager) {
         super(dispatcher, requestQueue, userAgent, httpAuthManager);
     }
 
     /**
      * Obtain the HTML response from a GET request for the given URL.
      */
-    public String getResponse(String url) throws DiscoveryException {
+    @Nullable
+    public String getResponse(@NonNull String url) throws DiscoveryException {
         BaseRequestFuture<String> future = BaseRequestFuture.newFuture();
         DiscoveryRequest request = new DiscoveryRequest(url, future, future);
         add(request);
@@ -63,8 +68,8 @@ public String getResponse(String url) throws DiscoveryException {
                     throw new DiscoveryException(DiscoveryError.XMLRPC_FORBIDDEN, url);
                 }
             } else if (e.getCause() instanceof NoConnectionError
-                    && e.getCause().getCause() instanceof SSLHandshakeException
-                    && e.getCause().getCause().getCause() instanceof CertificateException) {
+                       && e.getCause().getCause() instanceof SSLHandshakeException
+                       && e.getCause().getCause().getCause() instanceof CertificateException) {
                 // In the event of an SSL handshake error we should stop attempting discovery
                 throw new DiscoveryException(DiscoveryError.ERRONEOUS_SSL_CERTIFICATE, url);
             }
@@ -73,9 +78,10 @@ public String getResponse(String url) throws DiscoveryException {
     }
 
     /**
-     * Peform a system.listMethods call on the given URL.
+     * Perform a system.listMethods call on the given URL.
      */
-    public Object[] listMethods(String url) throws DiscoveryException {
+    @Nullable
+    public Object[] listMethods(@NonNull String url) throws DiscoveryException {
         if (!UrlUtils.isValidUrlAndHostNotNull(url)) {
             AppLog.e(AppLog.T.NUX, "Invalid URL: " + url);
             throw new DiscoveryException(DiscoveryError.INVALID_URL, url);
@@ -104,8 +110,8 @@ public Object[] listMethods(String url) throws DiscoveryException {
                     throw new DiscoveryException(DiscoveryError.XMLRPC_FORBIDDEN, url);
                 }
             } else if (e.getCause() instanceof NoConnectionError
-                    && e.getCause().getCause() instanceof SSLHandshakeException
-                    && e.getCause().getCause().getCause() instanceof CertificateException) {
+                       && e.getCause().getCause() instanceof SSLHandshakeException
+                       && e.getCause().getCause().getCause() instanceof CertificateException) {
                 // In the event of an SSL handshake error we should stop attempting discovery
                 throw new DiscoveryException(DiscoveryError.ERRONEOUS_SSL_CERTIFICATE, url);
             } else if (e.getCause() instanceof ServerError) {

libs/fluxc/src/main/java/org/wordpress/android/fluxc/network/discovery/DiscoveryXMLRPCRequest.java

@@ -13,11 +13,15 @@
  * {@link AuthenticationAction#AUTHENTICATE_ERROR} events.
  */
 public class DiscoveryXMLRPCRequest extends XMLRPCRequest {
-    DiscoveryXMLRPCRequest(String url, XMLRPC method, Listener<? super Object[]> listener,
-                           BaseErrorListener errorListener) {
+    DiscoveryXMLRPCRequest(
+            @NonNull String url,
+            @NonNull XMLRPC method,
+            @NonNull Listener<? super Object[]> listener,
+            @NonNull BaseErrorListener errorListener) {
         super(url, method, null, listener, errorListener);
     }
 
+    @NonNull
     @Override
     public BaseNetworkError deliverBaseNetworkError(@NonNull BaseNetworkError error) {
         // no op