Customizing date format in Java jersey2 client

modules/swagger-codegen/src/main/resources/Java/libraries/jersey2/ApiClient.mustache

@@ -60,13 +60,15 @@ public class ApiClient {
   private DateFormat dateFormat;
 
   public ApiClient() {
-    // Use ISO 8601 format for date and datetime.
-    // See https://en.wikipedia.org/wiki/ISO_8601
-    this.dateFormat = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSSZ");
+    // Use RFC3339 format for date and datetime.
+    // See http://xml2rfc.ietf.org/public/rfc/html/rfc3339.html#anchor14
+    this.dateFormat = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSSXXX");
 
     // Use UTC as the default time zone.
     this.dateFormat.setTimeZone(TimeZone.getTimeZone("UTC"));
 
+    this.json.setDateFormat((DateFormat) dateFormat.clone());
+
     // Set default User-Agent.
     setUserAgent("Java-Swagger");
 
@@ -81,6 +83,13 @@ public class ApiClient {
     authentications = Collections.unmodifiableMap(authentications);
   }
 
+  /**
+   * Gets the JSON instance to do JSON serialization and deserialization.
+   */
+  public JSON getJSON() {
+    return json;
+  }
+
   public String getBasePath() {
     return basePath;
   }
@@ -235,6 +244,8 @@ public class ApiClient {
    */
   public ApiClient setDateFormat(DateFormat dateFormat) {
     this.dateFormat = dateFormat;
+    // also set the date format for model (de)serialization with Date properties
+    this.json.setDateFormat((DateFormat) dateFormat.clone());
     return this;
   }