[OAuth] Added capability for custom deserializer (#1891)

* Added capability for custom deserializer

Closes #1888

Signed-off-by: clinique <gael@lhopital.org>

bundles/org.openhab.core.auth.oauth2client/src/main/java/org/openhab/core/auth/oauth2client/internal/OAuthClientServiceImpl.java

@@ -35,6 +35,8 @@ import org.openhab.core.io.net.http.HttpClientFactory;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import com.google.gson.JsonDeserializer;
+
 /**
  * Implementation of OAuthClientService.
  *
@@ -49,6 +51,7 @@ import org.slf4j.LoggerFactory;
  *
  * @author Michael Bock - Initial contribution
  * @author Gary Tse - Initial contribution
+ * @author Gaël L'hopital - Added capability for custom deserializer
  */
 @NonNullByDefault
 public class OAuthClientServiceImpl implements OAuthClientService {
@@ -150,7 +153,7 @@ public class OAuthClientServiceImpl implements OAuthClientService {
             throw new OAuthException("Missing client ID");
         }
 
-        OAuthConnector connector = new OAuthConnector(httpClientFactory);
+        OAuthConnector connector = new OAuthConnector(httpClientFactory, persistedParams.deserializerClassName);
         return connector.getAuthorizationUrl(authorizationUrl, clientId, redirectURI, persistedParams.state,
                 scopeToUse);
     }
@@ -204,7 +207,7 @@ public class OAuthClientServiceImpl implements OAuthClientService {
             throw new OAuthException("Missing client ID");
         }
 
-        OAuthConnector connector = new OAuthConnector(httpClientFactory);
+        OAuthConnector connector = new OAuthConnector(httpClientFactory, persistedParams.deserializerClassName);
         AccessTokenResponse accessTokenResponse = connector.grantTypeAuthorizationCode(tokenUrl, authorizationCode,
                 clientId, persistedParams.clientSecret, redirectURI,
                 Boolean.TRUE.equals(persistedParams.supportsBasicAuth));
@@ -236,7 +239,7 @@ public class OAuthClientServiceImpl implements OAuthClientService {
             throw new OAuthException("Missing token url");
         }
 
-        OAuthConnector connector = new OAuthConnector(httpClientFactory);
+        OAuthConnector connector = new OAuthConnector(httpClientFactory, persistedParams.deserializerClassName);
         AccessTokenResponse accessTokenResponse = connector.grantTypePassword(tokenUrl, username, password,
                 persistedParams.clientId, persistedParams.clientSecret, scope,
                 Boolean.TRUE.equals(persistedParams.supportsBasicAuth));
@@ -261,7 +264,7 @@ public class OAuthClientServiceImpl implements OAuthClientService {
             throw new OAuthException("Missing client ID");
         }
 
-        OAuthConnector connector = new OAuthConnector(httpClientFactory);
+        OAuthConnector connector = new OAuthConnector(httpClientFactory, persistedParams.deserializerClassName);
         // depending on usage, cannot guarantee every parameter is not null at the beginning
         AccessTokenResponse accessTokenResponse = connector.grantTypeClientCredentials(tokenUrl, clientId,
                 persistedParams.clientSecret, scope, Boolean.TRUE.equals(persistedParams.supportsBasicAuth));
@@ -295,7 +298,7 @@ public class OAuthClientServiceImpl implements OAuthClientService {
             throw new OAuthException("tokenUrl is required but null");
         }
 
-        OAuthConnector connector = new OAuthConnector(httpClientFactory);
+        OAuthConnector connector = new OAuthConnector(httpClientFactory, persistedParams.deserializerClassName);
         AccessTokenResponse accessTokenResponse = connector.grantTypeRefreshToken(tokenUrl,
                 lastAccessToken.getRefreshToken(), persistedParams.clientId, persistedParams.clientSecret,
                 persistedParams.scope, Boolean.TRUE.equals(persistedParams.supportsBasicAuth));
@@ -395,4 +398,17 @@ public class OAuthClientServiceImpl implements OAuthClientService {
     private String createNewState() {
         return UUID.randomUUID().toString();
     }
+
+    @Override
+    public <T extends JsonDeserializer<?>> OAuthClientService withDeserializer(Class<T> deserializerClass) {
+        OAuthClientServiceImpl clientService = new OAuthClientServiceImpl(handle, persistedParams.tokenExpiresInSeconds,
+                httpClientFactory);
+        persistedParams.deserializerClassName = deserializerClass.getName();
+        clientService.persistedParams = persistedParams;
+        clientService.storeHandler = storeHandler;
+
+        storeHandler.savePersistedParams(handle, clientService.persistedParams);
+
+        return clientService;
+    }
 }

bundles/org.openhab.core.auth.oauth2client/src/main/java/org/openhab/core/auth/oauth2client/internal/OAuthConnector.java

@@ -15,6 +15,7 @@ package org.openhab.core.auth.oauth2client.internal;
 import static org.openhab.core.auth.oauth2client.internal.Keyword.*;
 
 import java.io.IOException;
+import java.lang.reflect.InvocationTargetException;
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
 import java.security.AccessController;
@@ -65,9 +66,21 @@ public class OAuthConnector {
     private final Logger logger = LoggerFactory.getLogger(OAuthConnector.class);
     private final Gson gson;
 
-    public OAuthConnector(HttpClientFactory httpClientFactory) {
+    public OAuthConnector(HttpClientFactory httpClientFactory, @Nullable String deserializerClassName) {
         this.httpClientFactory = httpClientFactory;
-        gson = new GsonBuilder().setFieldNamingPolicy(FieldNamingPolicy.LOWER_CASE_WITH_UNDERSCORES).create();
+        GsonBuilder gsonBuilder = new GsonBuilder().setFieldNamingPolicy(FieldNamingPolicy.LOWER_CASE_WITH_UNDERSCORES);
+        if (deserializerClassName != null) {
+            try {
+                Class<?> deserializerClass = Class.forName(deserializerClassName);
+                gsonBuilder = gsonBuilder.registerTypeAdapter(AccessTokenResponse.class,
+                        deserializerClass.getConstructor().newInstance());
+            } catch (InstantiationException | IllegalAccessException | IllegalArgumentException
+                    | InvocationTargetException | NoSuchMethodException | SecurityException
+                    | ClassNotFoundException e) {
+                logger.error("Unable to construct custom deserializer '{}'", deserializerClassName, e);
+            }
+        }
+        gson = gsonBuilder.create();
     }
 
     /**

bundles/org.openhab.core.auth.oauth2client/src/main/java/org/openhab/core/auth/oauth2client/internal/OAuthFactoryImpl.java

@@ -70,7 +70,7 @@ public class OAuthFactoryImpl implements OAuthFactory {
             @Nullable Boolean supportsBasicAuth) {
         PersistedParams params = oAuthStoreHandler.loadPersistedParams(handle);
         PersistedParams newParams = new PersistedParams(handle, tokenUrl, authorizationUrl, clientId, clientSecret,
-                scope, supportsBasicAuth, tokenExpiresInBuffer);
+                scope, supportsBasicAuth, tokenExpiresInBuffer, null);
         OAuthClientService clientImpl = null;
 
         // If parameters in storage and parameters are the same as arguments passed get the client from storage

bundles/org.openhab.core.auth.oauth2client/src/main/java/org/openhab/core/auth/oauth2client/internal/PersistedParams.java

@@ -20,6 +20,7 @@ import org.eclipse.jdt.annotation.Nullable;
  * @author Michael Bock - Initial contribution
  * @author Gary Tse - Initial contribution
  * @author Hilbrand Bouwkamp - Moved class to it's own file and added hashCode and equals methods
+ * @author Gaël L'hopital - Added deserializerClassName
  */
 class PersistedParams {
     String handle;
@@ -32,6 +33,8 @@ class PersistedParams {
     String state;
     String redirectUri;
     int tokenExpiresInSeconds = 60;
+    @Nullable
+    String deserializerClassName;
 
     /**
      * Default constructor needed for json serialization.
@@ -56,9 +59,11 @@ class PersistedParams {
      *            of the access tokens. This allows the access token to expire earlier than the
      *            official stated expiry time; thus prevents the caller obtaining a valid token at the time of invoke,
      *            only to find the token immediately expired.
+     * @param deserializerClass (optional) if a specific deserializer is needed
      */
     public PersistedParams(String handle, String tokenUrl, String authorizationUrl, String clientId,
-            String clientSecret, String scope, Boolean supportsBasicAuth, int tokenExpiresInSeconds) {
+            String clientSecret, String scope, Boolean supportsBasicAuth, int tokenExpiresInSeconds,
+            @Nullable String deserializerClassName) {
         this.handle = handle;
         this.tokenUrl = tokenUrl;
         this.authorizationUrl = authorizationUrl;
@@ -67,6 +72,7 @@ class PersistedParams {
         this.scope = scope;
         this.supportsBasicAuth = supportsBasicAuth;
         this.tokenExpiresInSeconds = tokenExpiresInSeconds;
+        this.deserializerClassName = deserializerClassName;
     }
 
     @Override
@@ -83,6 +89,7 @@ class PersistedParams {
         result = prime * result + ((supportsBasicAuth == null) ? 0 : supportsBasicAuth.hashCode());
         result = prime * result + tokenExpiresInSeconds;
         result = prime * result + ((tokenUrl == null) ? 0 : tokenUrl.hashCode());
+        result = prime * result + ((deserializerClassName != null) ? deserializerClassName.hashCode() : 0);
         return result;
     }
 
@@ -161,6 +168,14 @@ class PersistedParams {
         } else if (!tokenUrl.equals(other.tokenUrl)) {
             return false;
         }
+        if (deserializerClassName == null) {
+            if (other.deserializerClassName != null) {
+                return false;
+            }
+        } else if (deserializerClassName != null && !deserializerClassName.equals(other.deserializerClassName)) {
+            return false;
+        }
+
         return true;
     }
 }

bundles/org.openhab.core/src/main/java/org/openhab/core/auth/client/oauth2/OAuthClientService.java

@@ -17,6 +17,8 @@ import java.io.IOException;
 import org.eclipse.jdt.annotation.NonNullByDefault;
 import org.eclipse.jdt.annotation.Nullable;
 
+import com.google.gson.JsonDeserializer;
+
 /**
  * This is the service factory to produce a OAuth2 service client that authenticates using OAUTH2.
  * This is a service factory pattern; the OAuthe2 service client is not shared between bundles.
@@ -77,6 +79,7 @@ import org.eclipse.jdt.annotation.Nullable;
  *
  * @author Gary Tse - Initial contribution
  * @author Hilbrand Bouwkamp - Added AccessTokenRefreshListener, fixed javadoc warnings
+ * @author Gaël L'hopital - Added capability for custom deserializer
  */
 @NonNullByDefault
 public interface OAuthClientService extends AutoCloseable {
@@ -286,4 +289,12 @@ public interface OAuthClientService extends AutoCloseable {
      * @param listener the listener to remove
      */
     boolean removeAccessTokenRefreshListener(AccessTokenRefreshListener listener);
+
+    /**
+     * Adds a personalized deserializer to a given oauth service.
+     *
+     * @param deserializeClass the deserializer class that should be used to deserialize AccessTokenResponse
+     * @return the oauth service
+     */
+    <T extends JsonDeserializer<?>> OAuthClientService withDeserializer(Class<T> deserializerClass);
 }