diff --git a/modules/swagger-codegen/src/main/resources/Java/libraries/jersey2/ApiClient.mustache b/modules/swagger-codegen/src/main/resources/Java/libraries/jersey2/ApiClient.mustache
index 517b6e1c8aa..24de11aedaa 100644
--- a/modules/swagger-codegen/src/main/resources/Java/libraries/jersey2/ApiClient.mustache
+++ b/modules/swagger-codegen/src/main/resources/Java/libraries/jersey2/ApiClient.mustache
@@ -498,8 +498,15 @@ public class ApiClient {
    * Deserialize response body to Java object according to the Content-Type.
    */
   public <T> T deserialize(Response response, GenericType<T> returnType) throws ApiException {
-    // Handle file downloading.
-    if (returnType.equals(File.class)) {
+    if (response == null || returnType == null) {
+      return null;
+    }
+
+    if ("byte[]".equals(returnType.toString())) {
+      // Handle binary response (byte array).
+      return (T) response.readEntity(byte[].class);
+    } else if (returnType.equals(File.class)) {
+      // Handle file downloading.
       @SuppressWarnings("unchecked")
       T file = (T) downloadFileFromResponse(response);
       return file;
diff --git a/samples/client/petstore/java/jersey2-java8/src/main/java/io/swagger/client/ApiClient.java b/samples/client/petstore/java/jersey2-java8/src/main/java/io/swagger/client/ApiClient.java
index 06f6d4d899a..617049afbcd 100644
--- a/samples/client/petstore/java/jersey2-java8/src/main/java/io/swagger/client/ApiClient.java
+++ b/samples/client/petstore/java/jersey2-java8/src/main/java/io/swagger/client/ApiClient.java
@@ -497,8 +497,15 @@ public class ApiClient {
    * Deserialize response body to Java object according to the Content-Type.
    */
   public <T> T deserialize(Response response, GenericType<T> returnType) throws ApiException {
-    // Handle file downloading.
-    if (returnType.equals(File.class)) {
+    if (response == null || returnType == null) {
+      return null;
+    }
+
+    if ("byte[]".equals(returnType.toString())) {
+      // Handle binary response (byte array).
+      return (T) response.readEntity(byte[].class);
+    } else if (returnType.equals(File.class)) {
+      // Handle file downloading.
       @SuppressWarnings("unchecked")
       T file = (T) downloadFileFromResponse(response);
       return file;
diff --git a/samples/client/petstore/java/jersey2/src/main/java/io/swagger/client/ApiClient.java b/samples/client/petstore/java/jersey2/src/main/java/io/swagger/client/ApiClient.java
index 06f6d4d899a..617049afbcd 100644
--- a/samples/client/petstore/java/jersey2/src/main/java/io/swagger/client/ApiClient.java
+++ b/samples/client/petstore/java/jersey2/src/main/java/io/swagger/client/ApiClient.java
@@ -497,8 +497,15 @@ public class ApiClient {
    * Deserialize response body to Java object according to the Content-Type.
    */
   public <T> T deserialize(Response response, GenericType<T> returnType) throws ApiException {
-    // Handle file downloading.
-    if (returnType.equals(File.class)) {
+    if (response == null || returnType == null) {
+      return null;
+    }
+
+    if ("byte[]".equals(returnType.toString())) {
+      // Handle binary response (byte array).
+      return (T) response.readEntity(byte[].class);
+    } else if (returnType.equals(File.class)) {
+      // Handle file downloading.
       @SuppressWarnings("unchecked")
       T file = (T) downloadFileFromResponse(response);
       return file;