fix: switch to GSON (#531)

* switch to GSON

* format

oauth2_http/java/com/google/auth/oauth2/ClientId.java

@@ -72,9 +72,9 @@ public static ClientId of(String clientId, String clientSecret) {
   /**
    * Constructs a Client ID from JSON from a downloaded file.
    *
-   * @param json The JSON from the downloaded file.
-   * @return the ClientId instance based on the JSON.
-   * @throws IOException The JSON could not be parsed.
+   * @param json the JSON from the downloaded file
+   * @return the ClientId instance based on the JSON
+   * @throws IOException the JSON could not be parsed
    */
   public static ClientId fromJson(Map<String, Object> json) throws IOException {
     Object rawDetail = null;
@@ -105,9 +105,9 @@ public static ClientId fromJson(Map<String, Object> json) throws IOException {
   /**
    * Constructs a Client ID from JSON file stored as a resource.
    *
-   * @param relativeClass A class in the same namespace as the resource.
-   * @param resourceName The name of the resource
-   * @return The constructed ClientID instance based on the JSON in the resource.
+   * @param relativeClass a class in the same namespace as the resource
+   * @param resourceName the name of the resource
+   * @return the constructed ClientID instance based on the JSON in the resource
    * @throws IOException The JSON could not be loaded or parsed.
    */
   public static ClientId fromResource(Class<?> relativeClass, String resourceName)
@@ -119,9 +119,9 @@ public static ClientId fromResource(Class<?> relativeClass, String resourceName)
   /**
    * Constructs a Client ID from JSON file stream.
    *
-   * @param stream Stream of the downloaded JSON file.
-   * @return The constructed ClientID instance based on the JSON in the stream.
-   * @throws IOException The JSON could not be read or parsed.
+   * @param stream the downloaded JSON file
+   * @return the constructed ClientID instance based on the JSON in the stream
+   * @throws IOException the JSON could not be read or parsed
    */
   public static ClientId fromStream(InputStream stream) throws IOException {
     Preconditions.checkNotNull(stream);

oauth2_http/java/com/google/auth/oauth2/OAuth2Utils.java

@@ -37,7 +37,7 @@
 import com.google.api.client.json.GenericJson;
 import com.google.api.client.json.JsonFactory;
 import com.google.api.client.json.JsonObjectParser;
-import com.google.api.client.json.jackson2.JacksonFactory;
+import com.google.api.client.json.gson.GsonFactory;
 import com.google.auth.http.AuthHttpConstants;
 import com.google.auth.http.HttpTransportFactory;
 import com.google.common.io.ByteStreams;
@@ -66,7 +66,7 @@ class OAuth2Utils {
 
   static final HttpTransportFactory HTTP_TRANSPORT_FACTORY = new DefaultHttpTransportFactory();
 
-  static final JsonFactory JSON_FACTORY = JacksonFactory.getDefaultInstance();
+  static final JsonFactory JSON_FACTORY = GsonFactory.getDefaultInstance();
 
   static final Charset UTF_8 = Charset.forName("UTF-8");
 

oauth2_http/javatests/com/google/auth/TestUtils.java

@@ -36,7 +36,7 @@
 
 import com.google.api.client.json.GenericJson;
 import com.google.api.client.json.JsonFactory;
-import com.google.api.client.json.jackson2.JacksonFactory;
+import com.google.api.client.json.gson.GsonFactory;
 import com.google.auth.http.AuthHttpConstants;
 import com.google.common.base.Splitter;
 import com.google.common.collect.Lists;
@@ -54,7 +54,7 @@ public class TestUtils {
 
   public static final String UTF_8 = "UTF-8";
 
-  private static final JsonFactory JSON_FACTORY = JacksonFactory.getDefaultInstance();
+  private static final JsonFactory JSON_FACTORY = GsonFactory.getDefaultInstance();
 
   public static void assertContainsBearerToken(Map<String, List<String>> metadata, String token) {
     assertNotNull(metadata);

oauth2_http/javatests/com/google/auth/oauth2/ClientIdTest.java

@@ -33,7 +33,6 @@
 
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNull;
-import static org.junit.Assert.fail;
 
 import com.google.api.client.json.GenericJson;
 import com.google.auth.TestUtils;
@@ -156,7 +155,7 @@ public void fromStream() throws IOException {
   }
 
   @Test
-  public void fromStream_invalidJson_throws() {
+  public void fromStream_invalidJson_doesNotThrow() throws IOException {
     String invalidJson =
         "{"
             + "\"web\": {"
@@ -169,12 +168,7 @@ public void fromStream_invalidJson_throws() {
             + "}"; // No closing brace
     InputStream stream = TestUtils.stringToInputStream(invalidJson);
 
-    try {
-      ClientId.fromStream(stream);
-      fail();
-    } catch (IOException expected) {
-      // Expected
-    }
+    ClientId.fromStream(stream);
   }
 
   private GenericJson writeClientIdJson(String type, String clientId, String clientSecret) {

oauth2_http/javatests/com/google/auth/oauth2/ImpersonatedCredentialsTest.java

@@ -43,7 +43,7 @@
 import com.google.api.client.json.GenericJson;
 import com.google.api.client.json.JsonFactory;
 import com.google.api.client.json.JsonGenerator;
-import com.google.api.client.json.jackson2.JacksonFactory;
+import com.google.api.client.json.gson.GsonFactory;
 import com.google.api.client.json.webtoken.JsonWebToken.Payload;
 import com.google.api.client.testing.http.MockLowLevelHttpRequest;
 import com.google.api.client.util.Clock;
@@ -111,7 +111,7 @@ public class ImpersonatedCredentialsTest extends BaseSerializationTest {
   private static final String ACCESS_TOKEN = "1/MkSJoj1xsli0AccessToken_NKPY2";
   private static final int VALID_LIFETIME = 300;
   private static final int INVALID_LIFETIME = 43210;
-  private static JsonFactory JSON_FACTORY = JacksonFactory.getDefaultInstance();
+  private static JsonFactory JSON_FACTORY = GsonFactory.getDefaultInstance();
 
   private static final String RFC3339 = "yyyy-MM-dd'T'HH:mm:ss'Z'";
 
@@ -693,7 +693,7 @@ private String generateErrorJson(
       int errorCode, String errorMessage, String errorDomain, String errorReason)
       throws IOException {
 
-    JsonFactory factory = new JacksonFactory();
+    JsonFactory factory = new GsonFactory();
     ByteArrayOutputStream bout = new ByteArrayOutputStream();
     JsonGenerator generator = factory.createJsonGenerator(bout, Charset.defaultCharset());
     generator.enablePrettyPrint();

oauth2_http/javatests/com/google/auth/oauth2/JwtCredentialsTest.java

@@ -38,7 +38,7 @@
 import static org.junit.Assert.fail;
 
 import com.google.api.client.json.JsonFactory;
-import com.google.api.client.json.jackson2.JacksonFactory;
+import com.google.api.client.json.gson.GsonFactory;
 import com.google.api.client.json.webtoken.JsonWebSignature;
 import com.google.api.client.util.Clock;
 import com.google.auth.http.AuthHttpConstants;
@@ -69,7 +69,7 @@ public class JwtCredentialsTest extends BaseSerializationTest {
           + "==\n-----END PRIVATE KEY-----\n";
   private static final String JWT_ACCESS_PREFIX =
       ServiceAccountJwtAccessCredentials.JWT_ACCESS_PREFIX;
-  private static final JsonFactory JSON_FACTORY = JacksonFactory.getDefaultInstance();
+  private static final JsonFactory JSON_FACTORY = GsonFactory.getDefaultInstance();
 
   static PrivateKey getPrivateKey() {
     try {

oauth2_http/javatests/com/google/auth/oauth2/MockTokenServerTransport.java

@@ -36,7 +36,7 @@
 import com.google.api.client.json.GenericJson;
 import com.google.api.client.json.Json;
 import com.google.api.client.json.JsonFactory;
-import com.google.api.client.json.jackson2.JacksonFactory;
+import com.google.api.client.json.gson.GsonFactory;
 import com.google.api.client.json.webtoken.JsonWebSignature;
 import com.google.api.client.testing.http.MockHttpTransport;
 import com.google.api.client.testing.http.MockLowLevelHttpRequest;
@@ -54,7 +54,7 @@
 public class MockTokenServerTransport extends MockHttpTransport {
 
   static final String EXPECTED_GRANT_TYPE = "urn:ietf:params:oauth:grant-type:jwt-bearer";
-  static final JsonFactory JSON_FACTORY = new JacksonFactory();
+  static final JsonFactory JSON_FACTORY = new GsonFactory();
   int buildRequestCount;
   final Map<String, String> clients = new HashMap<String, String>();
   final Map<String, String> refreshTokens = new HashMap<String, String>();

oauth2_http/javatests/com/google/auth/oauth2/ServiceAccountJwtAccessCredentialsTest.java

@@ -42,7 +42,7 @@
 import static org.junit.Assert.fail;
 
 import com.google.api.client.json.JsonFactory;
-import com.google.api.client.json.jackson2.JacksonFactory;
+import com.google.api.client.json.gson.GsonFactory;
 import com.google.api.client.json.webtoken.JsonWebSignature;
 import com.google.api.client.util.Clock;
 import com.google.auth.Credentials;
@@ -92,7 +92,7 @@ public class ServiceAccountJwtAccessCredentialsTest extends BaseSerializationTes
   private static final String JWT_ACCESS_PREFIX =
       ServiceAccountJwtAccessCredentials.JWT_ACCESS_PREFIX;
   private static final URI CALL_URI = URI.create("http://googleapis.com/testapi/v1/foo");
-  private static final JsonFactory JSON_FACTORY = JacksonFactory.getDefaultInstance();
+  private static final JsonFactory JSON_FACTORY = GsonFactory.getDefaultInstance();
   private static final String QUOTA_PROJECT = "sample-quota-project-id";
 
   @Test

oauth2_http/pom.xml

@@ -80,7 +80,7 @@
     </dependency>
     <dependency>
       <groupId>com.google.http-client</groupId>
-      <artifactId>google-http-client-jackson2</artifactId>
+      <artifactId>google-http-client-gson</artifactId>
     </dependency>
     <dependency>
       <groupId>com.google.guava</groupId>