fix: handle gzip response in v2-settings

Author: Abhi591

CHANGELOG.md

@@ -5,6 +5,11 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [1.12.1] - 2025-09-09
+
+### Fixed
+- Handle case where we are getting Gzip-compressed response for v2-settings
+
 ## [1.12.0] - 2025-09-01
 
 ### Fixed

pom.xml

@@ -19,7 +19,7 @@ limitations under the License. -->
 
     <groupId>com.vwo.sdk</groupId>
     <artifactId>vwo-fme-java-sdk</artifactId>
-    <version>1.12.0</version>
+    <version>1.12.1</version>
     <packaging>jar</packaging>
 
     <name>VWO FME Java SDK</name>

src/main/java/com/vwo/constants/Constants.java

@@ -28,7 +28,7 @@ public class Constants {
   public static final int DEFAULT_REQUEST_TIME_INTERVAL = 600; // 10 * 60(secs) = 600 secs i.e. 10 minutes
   public static final int DEFAULT_EVENTS_PER_REQUEST = 100;
   public static final String SDK_NAME = "vwo-fme-java-sdk";
-  public static final String SDK_VERSION = "1.12.0";
+  public static final String SDK_VERSION = "1.12.1";
   public static final long SETTINGS_EXPIRY = 10000000;
   public static final long SETTINGS_TIMEOUT = 50000;
 

src/main/java/com/vwo/packages/network_layer/client/NetworkClient.java

@@ -20,7 +20,11 @@
 import com.vwo.packages.network_layer.models.RequestModel;
 import com.vwo.packages.network_layer.models.ResponseModel;
 
+import java.io.BufferedInputStream;
 import java.io.BufferedReader;
+import java.io.ByteArrayInputStream;
+import java.io.IOException;
+import java.io.InputStream;
 import java.io.InputStreamReader;
 import java.io.OutputStream;
 import java.net.HttpURLConnection;
@@ -29,6 +33,7 @@
 import java.util.HashMap;
 import java.util.LinkedHashMap;
 import java.util.Map;
+import java.util.zip.GZIPInputStream;
 
 public class NetworkClient implements NetworkClientInterface {
 
@@ -41,6 +46,40 @@ public static String constructUrl(Map<String, Object> networkOptions) {
     return networkOptions.get("scheme").toString().toLowerCase() + "://" + hostname + path;
   }
 
+  /**
+   * Magic Number Detection - Check first two bytes for gzip signature (0x1f, 0x8b)
+   * This is the most reliable method as it checks the actual content
+   */
+  private boolean isGzippedByMagicNumber(InputStream inputStream) throws IOException {
+    if (!inputStream.markSupported()) {
+      return false;
+    }
+    
+    inputStream.mark(2);
+    int byte1 = inputStream.read();
+    int byte2 = inputStream.read();
+    inputStream.reset();
+    
+    return (byte1 == 0x1f && byte2 == 0x8b);
+  }
+
+  /**
+   * This method is used to get the input stream from the connection
+   * @param connection The HttpURLConnection object
+   * @return The InputStream object
+   * @throws IOException If an I/O error occurs
+   */
+  private InputStream getInputStream(HttpURLConnection connection) throws IOException {
+    InputStream rawInputStream = connection.getInputStream();
+  
+    BufferedInputStream bufferedStream = new BufferedInputStream(rawInputStream);
+    if (isGzippedByMagicNumber(bufferedStream)) {
+      return new GZIPInputStream(bufferedStream);
+    }
+    
+    return bufferedStream;
+  }
+
   /**
    * Performs a GET request using the provided RequestModel.
    * @param requestModel The model containing request options.
@@ -71,7 +110,12 @@ public ResponseModel GET(RequestModel requestModel){
         return responseModel;
       }
 
-      BufferedReader in = new BufferedReader(new InputStreamReader(connection.getInputStream()));
+      // Use the comprehensive gzip detection method
+      InputStream inputStream = getInputStream(connection);
+      if (inputStream instanceof GZIPInputStream) {
+        responseModel.setIsGzipped(true);
+      }
+      BufferedReader in = new BufferedReader(new InputStreamReader(inputStream, StandardCharsets.UTF_8));
       String inputLine;
       StringBuilder response = new StringBuilder();
 

src/main/java/com/vwo/packages/network_layer/models/ResponseModel.java

@@ -23,6 +23,7 @@ public class ResponseModel {
   private Exception error;
   private Map<String, String> headers;
   private String data;
+  private boolean isGzipped;
 
   public void setStatusCode(int statusCode) {
     this.statusCode = statusCode;
@@ -55,4 +56,12 @@ public int getStatusCode() {
   public Exception getError() {
     return error;
   }
+
+  public void setIsGzipped(boolean isGzipped) {
+    this.isGzipped = isGzipped;
+  }
+
+  public boolean getIsGzipped() {
+    return isGzipped;
+  }
 }

src/main/java/com/vwo/services/SettingsManager.java

@@ -29,6 +29,7 @@
 import com.vwo.packages.network_layer.manager.NetworkManager;
 import com.vwo.packages.network_layer.models.RequestModel;
 import com.vwo.packages.network_layer.models.ResponseModel;
+import com.vwo.utils.LogMessageUtil;
 import com.vwo.utils.NetworkUtil;
 
 // public class SettingsManager implements ISettingsManager {
@@ -150,6 +151,11 @@ public String fetchSettings(Boolean isViaWebhook) {
                 });
                 return null;
             }
+            if (response.getIsGzipped()) {
+                try {
+                    LogMessageUtil.sendLogToVWO("Got Gzip response from the server for v2-settings", LogLevelEnum.DEBUG.name(), this);
+                } catch (Exception e) {}
+            }
             this.settingsFetchTime = System.currentTimeMillis() - startTime;
             return response.getData();
         } catch (Exception e) {