Fix NPE in isIdempotencyReplayed caused by null status-line header key

CHANGELOG.md

@@ -1,3 +1,9 @@
+### v4.17.2 (2026-10-21)
+* * *
+### Bug Fixes:
+* Fix `NullPointerException` in `isIdempotencyReplayed()` and `header()` when response headers contain the HTTP status line under a `null` key (as returned by `HttpURLConnection`). The `null` key is no longer exposed via `headers()`.
+* Treat the `chargebee-idempotency-key` header case-insensitively in `RequestOptions`, so `getIdempotencyKey()` finds keys set with any casing and the header is not sent twice.
+
 ### v4.17.1 (2026-10-19)
 * * *
 ### Bug Fixes:

VERSION

@@ -1 +1 @@
-4.17.1
+4.17.2

build.gradle.kts

@@ -7,7 +7,7 @@ plugins {
 }
 
 group = "com.chargebee"
-version = "4.17.1"
+version = "4.17.2"
 description = "Java client library for ChargeBee"
 
 // Project metadata

src/main/java/com/chargebee/v4/client/request/RequestOptions.java

@@ -12,6 +12,8 @@
  * Supports headers and can be extended for timeouts, retries, API versions, etc.
  */
 public final class RequestOptions {
+    private static final String IDEMPOTENCY_KEY_HEADER = "chargebee-idempotency-key";
+
     private final Map<String, String> headers;
     private final Integer maxNetworkRetries;
     private final Boolean retryEnabled;
@@ -61,13 +63,13 @@ public static Builder builder() {
 
     public RequestOptions withHeader(String key, String value) {
         Map<String, String> copy = new HashMap<>(headers);
-        copy.put(key, value);
+        putHeader(copy, key, value);
         return new RequestOptions(copy, maxNetworkRetries, retryEnabled, retryBaseDelayMs, retryOnStatus, connectTimeoutMs, readTimeoutMs, followRedirects, gzipCompression, requestLogger, telemetryAdapter);
     }
 
     public RequestOptions withHeaders(Map<String, String> newHeaders) {
         Map<String, String> copy = new HashMap<>(headers);
-        copy.putAll(newHeaders);
+        putHeaders(copy, newHeaders);
         return new RequestOptions(copy, maxNetworkRetries, retryEnabled, retryBaseDelayMs, retryOnStatus, connectTimeoutMs, readTimeoutMs, followRedirects, gzipCompression, requestLogger, telemetryAdapter);
     }
 
@@ -81,7 +83,17 @@ public Map<String, String> getHeaders() {
      * @return the idempotency key, or null if not set
      */
     public String getIdempotencyKey() {
-        return headers.get("chargebee-idempotency-key");
+        return headers.get(IDEMPOTENCY_KEY_HEADER);
+    }
+
+    private static void putHeader(Map<String, String> target, String name, String value) {
+        target.put(IDEMPOTENCY_KEY_HEADER.equalsIgnoreCase(name) ? IDEMPOTENCY_KEY_HEADER : name, value);
+    }
+
+    private static void putHeaders(Map<String, String> target, Map<String, String> source) {
+        for (Map.Entry<String, String> entry : source.entrySet()) {
+            putHeader(target, entry.getKey(), entry.getValue());
+        }
     }
 
     public Integer getMaxNetworkRetries() {
@@ -139,14 +151,14 @@ public static final class Builder {
 
         public Builder header(String name, String value) {
             if (name != null && value != null) {
-                headers.put(name, value);
+                putHeader(headers, name, value);
             }
             return this;
         }
 
         public Builder headers(Map<String, String> headers) {
             if (headers != null) {
-                this.headers.putAll(headers);
+                putHeaders(this.headers, headers);
             }
             return this;
         }
@@ -160,7 +172,7 @@ public Builder headers(Map<String, String> headers) {
          */
         public Builder idempotencyKey(String idempotencyKey) {
             if (idempotencyKey != null && !idempotencyKey.isEmpty()) {
-                this.headers.put("chargebee-idempotency-key", idempotencyKey);
+                this.headers.put(IDEMPOTENCY_KEY_HEADER, idempotencyKey);
             }
             return this;
         }

src/main/java/com/chargebee/v4/models/BaseResponse.java

@@ -35,7 +35,7 @@ public Map<String, List<String>> headers() {
   public List<String> header(String name) {
     if (httpResponse == null) return null;
     return httpResponse.getHeaders().entrySet().stream()
-        .filter(e -> e.getKey().equalsIgnoreCase(name))
+        .filter(e -> name.equalsIgnoreCase(e.getKey()))
         .map(Map.Entry::getValue)
         .findFirst()
         .orElse(null);

src/main/java/com/chargebee/v4/models/addon/responses/AddonListResponse.java

@@ -133,7 +133,7 @@ public java.util.Map<String, java.util.List<String>> headers() {
   public java.util.List<String> header(String name) {
     if (httpResponse == null) return null;
     return httpResponse.getHeaders().entrySet().stream()
-        .filter(e -> e.getKey().equalsIgnoreCase(name))
+        .filter(e -> name.equalsIgnoreCase(e.getKey()))
         .map(java.util.Map.Entry::getValue)
         .findFirst()
         .orElse(null);

src/main/java/com/chargebee/v4/models/alert/responses/AlertListResponse.java

@@ -133,7 +133,7 @@ public java.util.Map<String, java.util.List<String>> headers() {
   public java.util.List<String> header(String name) {
     if (httpResponse == null) return null;
     return httpResponse.getHeaders().entrySet().stream()
-        .filter(e -> e.getKey().equalsIgnoreCase(name))
+        .filter(e -> name.equalsIgnoreCase(e.getKey()))
         .map(java.util.Map.Entry::getValue)
         .findFirst()
         .orElse(null);

src/main/java/com/chargebee/v4/models/alert/responses/ApplicationAlertsForSubscriptionResponse.java

@@ -154,7 +154,7 @@ public java.util.Map<String, java.util.List<String>> headers() {
   public java.util.List<String> header(String name) {
     if (httpResponse == null) return null;
     return httpResponse.getHeaders().entrySet().stream()
-        .filter(e -> e.getKey().equalsIgnoreCase(name))
+        .filter(e -> name.equalsIgnoreCase(e.getKey()))
         .map(java.util.Map.Entry::getValue)
         .findFirst()
         .orElse(null);

src/main/java/com/chargebee/v4/models/alertStatus/responses/AlertStatusesForAlertResponse.java

@@ -149,7 +149,7 @@ public java.util.Map<String, java.util.List<String>> headers() {
   public java.util.List<String> header(String name) {
     if (httpResponse == null) return null;
     return httpResponse.getHeaders().entrySet().stream()
-        .filter(e -> e.getKey().equalsIgnoreCase(name))
+        .filter(e -> name.equalsIgnoreCase(e.getKey()))
         .map(java.util.Map.Entry::getValue)
         .findFirst()
         .orElse(null);

src/main/java/com/chargebee/v4/models/alertStatus/responses/AlertStatusesForSubscriptionResponse.java

@@ -154,7 +154,7 @@ public java.util.Map<String, java.util.List<String>> headers() {
   public java.util.List<String> header(String name) {
     if (httpResponse == null) return null;
     return httpResponse.getHeaders().entrySet().stream()
-        .filter(e -> e.getKey().equalsIgnoreCase(name))
+        .filter(e -> name.equalsIgnoreCase(e.getKey()))
         .map(java.util.Map.Entry::getValue)
         .findFirst()
         .orElse(null);

src/main/java/com/chargebee/v4/models/attachedItem/responses/AttachedItemListResponse.java

@@ -143,7 +143,7 @@ public java.util.Map<String, java.util.List<String>> headers() {
   public java.util.List<String> header(String name) {
     if (httpResponse == null) return null;
     return httpResponse.getHeaders().entrySet().stream()
-        .filter(e -> e.getKey().equalsIgnoreCase(name))
+        .filter(e -> name.equalsIgnoreCase(e.getKey()))
         .map(java.util.Map.Entry::getValue)
         .findFirst()
         .orElse(null);

src/main/java/com/chargebee/v4/models/businessEntity/responses/BusinessEntityGetTransfersResponse.java

@@ -143,7 +143,7 @@ public java.util.Map<String, java.util.List<String>> headers() {
   public java.util.List<String> header(String name) {
     if (httpResponse == null) return null;
     return httpResponse.getHeaders().entrySet().stream()
-        .filter(e -> e.getKey().equalsIgnoreCase(name))
+        .filter(e -> name.equalsIgnoreCase(e.getKey()))
         .map(java.util.Map.Entry::getValue)
         .findFirst()
         .orElse(null);

src/main/java/com/chargebee/v4/models/businessRule/responses/BusinessRuleListResponse.java

@@ -136,7 +136,7 @@ public java.util.Map<String, java.util.List<String>> headers() {
   public java.util.List<String> header(String name) {
     if (httpResponse == null) return null;
     return httpResponse.getHeaders().entrySet().stream()
-        .filter(e -> e.getKey().equalsIgnoreCase(name))
+        .filter(e -> name.equalsIgnoreCase(e.getKey()))
         .map(java.util.Map.Entry::getValue)
         .findFirst()
         .orElse(null);

src/main/java/com/chargebee/v4/models/businessRuleset/responses/BusinessRulesetListResponse.java

@@ -139,7 +139,7 @@ public java.util.Map<String, java.util.List<String>> headers() {
   public java.util.List<String> header(String name) {
     if (httpResponse == null) return null;
     return httpResponse.getHeaders().entrySet().stream()
-        .filter(e -> e.getKey().equalsIgnoreCase(name))
+        .filter(e -> name.equalsIgnoreCase(e.getKey()))
         .map(java.util.Map.Entry::getValue)
         .findFirst()
         .orElse(null);

src/main/java/com/chargebee/v4/models/comment/responses/CommentListResponse.java

@@ -136,7 +136,7 @@ public java.util.Map<String, java.util.List<String>> headers() {
   public java.util.List<String> header(String name) {
     if (httpResponse == null) return null;
     return httpResponse.getHeaders().entrySet().stream()
-        .filter(e -> e.getKey().equalsIgnoreCase(name))
+        .filter(e -> name.equalsIgnoreCase(e.getKey()))
         .map(java.util.Map.Entry::getValue)
         .findFirst()
         .orElse(null);

src/main/java/com/chargebee/v4/models/coupon/responses/CouponListResponse.java

@@ -133,7 +133,7 @@ public java.util.Map<String, java.util.List<String>> headers() {
   public java.util.List<String> header(String name) {
     if (httpResponse == null) return null;
     return httpResponse.getHeaders().entrySet().stream()
-        .filter(e -> e.getKey().equalsIgnoreCase(name))
+        .filter(e -> name.equalsIgnoreCase(e.getKey()))
         .map(java.util.Map.Entry::getValue)
         .findFirst()
         .orElse(null);

src/main/java/com/chargebee/v4/models/couponCode/responses/CouponCodeListResponse.java

@@ -136,7 +136,7 @@ public java.util.Map<String, java.util.List<String>> headers() {
   public java.util.List<String> header(String name) {
     if (httpResponse == null) return null;
     return httpResponse.getHeaders().entrySet().stream()
-        .filter(e -> e.getKey().equalsIgnoreCase(name))
+        .filter(e -> name.equalsIgnoreCase(e.getKey()))
         .map(java.util.Map.Entry::getValue)
         .findFirst()
         .orElse(null);

src/main/java/com/chargebee/v4/models/couponSet/responses/CouponSetListResponse.java

@@ -136,7 +136,7 @@ public java.util.Map<String, java.util.List<String>> headers() {
   public java.util.List<String> header(String name) {
     if (httpResponse == null) return null;
     return httpResponse.getHeaders().entrySet().stream()
-        .filter(e -> e.getKey().equalsIgnoreCase(name))
+        .filter(e -> name.equalsIgnoreCase(e.getKey()))
         .map(java.util.Map.Entry::getValue)
         .findFirst()
         .orElse(null);

src/main/java/com/chargebee/v4/models/creditNote/responses/CreditNoteListResponse.java

@@ -136,7 +136,7 @@ public java.util.Map<String, java.util.List<String>> headers() {
   public java.util.List<String> header(String name) {
     if (httpResponse == null) return null;
     return httpResponse.getHeaders().entrySet().stream()
-        .filter(e -> e.getKey().equalsIgnoreCase(name))
+        .filter(e -> name.equalsIgnoreCase(e.getKey()))
         .map(java.util.Map.Entry::getValue)
         .findFirst()
         .orElse(null);

src/main/java/com/chargebee/v4/models/creditNote/responses/CreditNotesForCustomerResponse.java

@@ -149,7 +149,7 @@ public java.util.Map<String, java.util.List<String>> headers() {
   public java.util.List<String> header(String name) {
     if (httpResponse == null) return null;
     return httpResponse.getHeaders().entrySet().stream()
-        .filter(e -> e.getKey().equalsIgnoreCase(name))
+        .filter(e -> name.equalsIgnoreCase(e.getKey()))
         .map(java.util.Map.Entry::getValue)
         .findFirst()
         .orElse(null);

src/main/java/com/chargebee/v4/models/creditUnit/responses/CreditUnitListResponse.java

@@ -136,7 +136,7 @@ public java.util.Map<String, java.util.List<String>> headers() {
   public java.util.List<String> header(String name) {
     if (httpResponse == null) return null;
     return httpResponse.getHeaders().entrySet().stream()
-        .filter(e -> e.getKey().equalsIgnoreCase(name))
+        .filter(e -> name.equalsIgnoreCase(e.getKey()))
         .map(java.util.Map.Entry::getValue)
         .findFirst()
         .orElse(null);

src/main/java/com/chargebee/v4/models/currency/responses/CurrencyListResponse.java

@@ -136,7 +136,7 @@ public java.util.Map<String, java.util.List<String>> headers() {
   public java.util.List<String> header(String name) {
     if (httpResponse == null) return null;
     return httpResponse.getHeaders().entrySet().stream()
-        .filter(e -> e.getKey().equalsIgnoreCase(name))
+        .filter(e -> name.equalsIgnoreCase(e.getKey()))
         .map(java.util.Map.Entry::getValue)
         .findFirst()
         .orElse(null);

src/main/java/com/chargebee/v4/models/customer/responses/ContactsForCustomerResponse.java

@@ -145,7 +145,7 @@ public java.util.Map<String, java.util.List<String>> headers() {
   public java.util.List<String> header(String name) {
     if (httpResponse == null) return null;
     return httpResponse.getHeaders().entrySet().stream()
-        .filter(e -> e.getKey().equalsIgnoreCase(name))
+        .filter(e -> name.equalsIgnoreCase(e.getKey()))
         .map(java.util.Map.Entry::getValue)
         .findFirst()
         .orElse(null);

src/main/java/com/chargebee/v4/models/customer/responses/CustomerListHierarchyDetailResponse.java

@@ -152,7 +152,7 @@ public java.util.Map<String, java.util.List<String>> headers() {
   public java.util.List<String> header(String name) {
     if (httpResponse == null) return null;
     return httpResponse.getHeaders().entrySet().stream()
-        .filter(e -> e.getKey().equalsIgnoreCase(name))
+        .filter(e -> name.equalsIgnoreCase(e.getKey()))
         .map(java.util.Map.Entry::getValue)
         .findFirst()
         .orElse(null);

src/main/java/com/chargebee/v4/models/customer/responses/CustomerListResponse.java

@@ -138,7 +138,7 @@ public java.util.Map<String, java.util.List<String>> headers() {
   public java.util.List<String> header(String name) {
     if (httpResponse == null) return null;
     return httpResponse.getHeaders().entrySet().stream()
-        .filter(e -> e.getKey().equalsIgnoreCase(name))
+        .filter(e -> name.equalsIgnoreCase(e.getKey()))
         .map(java.util.Map.Entry::getValue)
         .findFirst()
         .orElse(null);

src/main/java/com/chargebee/v4/models/customerEntitlement/responses/CustomerEntitlementEntitlementsForCustomerResponse.java

@@ -155,7 +155,7 @@ public java.util.Map<String, java.util.List<String>> headers() {
   public java.util.List<String> header(String name) {
     if (httpResponse == null) return null;
     return httpResponse.getHeaders().entrySet().stream()
-        .filter(e -> e.getKey().equalsIgnoreCase(name))
+        .filter(e -> name.equalsIgnoreCase(e.getKey()))
         .map(java.util.Map.Entry::getValue)
         .findFirst()
         .orElse(null);

src/main/java/com/chargebee/v4/models/differentialPrice/responses/DifferentialPriceListResponse.java

@@ -141,7 +141,7 @@ public java.util.Map<String, java.util.List<String>> headers() {
   public java.util.List<String> header(String name) {
     if (httpResponse == null) return null;
     return httpResponse.getHeaders().entrySet().stream()
-        .filter(e -> e.getKey().equalsIgnoreCase(name))
+        .filter(e -> name.equalsIgnoreCase(e.getKey()))
         .map(java.util.Map.Entry::getValue)
         .findFirst()
         .orElse(null);

src/main/java/com/chargebee/v4/models/dispute/responses/DisputeListResponse.java

@@ -136,7 +136,7 @@ public java.util.Map<String, java.util.List<String>> headers() {
   public java.util.List<String> header(String name) {
     if (httpResponse == null) return null;
     return httpResponse.getHeaders().entrySet().stream()
-        .filter(e -> e.getKey().equalsIgnoreCase(name))
+        .filter(e -> name.equalsIgnoreCase(e.getKey()))
         .map(java.util.Map.Entry::getValue)
         .findFirst()
         .orElse(null);

src/main/java/com/chargebee/v4/models/einvoice/responses/ListEinvoicesResponse.java

@@ -138,7 +138,7 @@ public java.util.Map<String, java.util.List<String>> headers() {
   public java.util.List<String> header(String name) {
     if (httpResponse == null) return null;
     return httpResponse.getHeaders().entrySet().stream()
-        .filter(e -> e.getKey().equalsIgnoreCase(name))
+        .filter(e -> name.equalsIgnoreCase(e.getKey()))
         .map(java.util.Map.Entry::getValue)
         .findFirst()
         .orElse(null);

src/main/java/com/chargebee/v4/models/emailLog/responses/EmailLogsForCustomerResponse.java

@@ -145,7 +145,7 @@ public java.util.Map<String, java.util.List<String>> headers() {
   public java.util.List<String> header(String name) {
     if (httpResponse == null) return null;
     return httpResponse.getHeaders().entrySet().stream()
-        .filter(e -> e.getKey().equalsIgnoreCase(name))
+        .filter(e -> name.equalsIgnoreCase(e.getKey()))
         .map(java.util.Map.Entry::getValue)
         .findFirst()
         .orElse(null);

src/main/java/com/chargebee/v4/models/entitlement/responses/EntitlementListResponse.java

@@ -136,7 +136,7 @@ public java.util.Map<String, java.util.List<String>> headers() {
   public java.util.List<String> header(String name) {
     if (httpResponse == null) return null;
     return httpResponse.getHeaders().entrySet().stream()
-        .filter(e -> e.getKey().equalsIgnoreCase(name))
+        .filter(e -> name.equalsIgnoreCase(e.getKey()))
         .map(java.util.Map.Entry::getValue)
         .findFirst()
         .orElse(null);

src/main/java/com/chargebee/v4/models/entitlementOverride/responses/ListEntitlementOverrideForSubscriptionResponse.java

@@ -155,7 +155,7 @@ public java.util.Map<String, java.util.List<String>> headers() {
   public java.util.List<String> header(String name) {
     if (httpResponse == null) return null;
     return httpResponse.getHeaders().entrySet().stream()
-        .filter(e -> e.getKey().equalsIgnoreCase(name))
+        .filter(e -> name.equalsIgnoreCase(e.getKey()))
         .map(java.util.Map.Entry::getValue)
         .findFirst()
         .orElse(null);

src/main/java/com/chargebee/v4/models/event/responses/EventListResponse.java

@@ -133,7 +133,7 @@ public java.util.Map<String, java.util.List<String>> headers() {
   public java.util.List<String> header(String name) {
     if (httpResponse == null) return null;
     return httpResponse.getHeaders().entrySet().stream()
-        .filter(e -> e.getKey().equalsIgnoreCase(name))
+        .filter(e -> name.equalsIgnoreCase(e.getKey()))
         .map(java.util.Map.Entry::getValue)
         .findFirst()
         .orElse(null);

src/main/java/com/chargebee/v4/models/feature/responses/FeatureListResponse.java

@@ -136,7 +136,7 @@ public java.util.Map<String, java.util.List<String>> headers() {
   public java.util.List<String> header(String name) {
     if (httpResponse == null) return null;
     return httpResponse.getHeaders().entrySet().stream()
-        .filter(e -> e.getKey().equalsIgnoreCase(name))
+        .filter(e -> name.equalsIgnoreCase(e.getKey()))
         .map(java.util.Map.Entry::getValue)
         .findFirst()
         .orElse(null);

src/main/java/com/chargebee/v4/models/gift/responses/GiftListResponse.java

@@ -135,7 +135,7 @@ public java.util.Map<String, java.util.List<String>> headers() {
   public java.util.List<String> header(String name) {
     if (httpResponse == null) return null;
     return httpResponse.getHeaders().entrySet().stream()
-        .filter(e -> e.getKey().equalsIgnoreCase(name))
+        .filter(e -> name.equalsIgnoreCase(e.getKey()))
         .map(java.util.Map.Entry::getValue)
         .findFirst()
         .orElse(null);

src/main/java/com/chargebee/v4/models/grantBlock/responses/ListGrantBlocksResponse.java

@@ -138,7 +138,7 @@ public java.util.Map<String, java.util.List<String>> headers() {
   public java.util.List<String> header(String name) {
     if (httpResponse == null) return null;
     return httpResponse.getHeaders().entrySet().stream()
-        .filter(e -> e.getKey().equalsIgnoreCase(name))
+        .filter(e -> name.equalsIgnoreCase(e.getKey()))
         .map(java.util.Map.Entry::getValue)
         .findFirst()
         .orElse(null);

src/main/java/com/chargebee/v4/models/hostedPage/responses/HostedPageListResponse.java

@@ -136,7 +136,7 @@ public java.util.Map<String, java.util.List<String>> headers() {
   public java.util.List<String> header(String name) {
     if (httpResponse == null) return null;
     return httpResponse.getHeaders().entrySet().stream()
-        .filter(e -> e.getKey().equalsIgnoreCase(name))
+        .filter(e -> name.equalsIgnoreCase(e.getKey()))
         .map(java.util.Map.Entry::getValue)
         .findFirst()
         .orElse(null);

src/main/java/com/chargebee/v4/models/invoice/responses/InvoiceListPaymentReferenceNumbersResponse.java

@@ -148,7 +148,7 @@ public java.util.Map<String, java.util.List<String>> headers() {
   public java.util.List<String> header(String name) {
     if (httpResponse == null) return null;
     return httpResponse.getHeaders().entrySet().stream()
-        .filter(e -> e.getKey().equalsIgnoreCase(name))
+        .filter(e -> name.equalsIgnoreCase(e.getKey()))
         .map(java.util.Map.Entry::getValue)
         .findFirst()
         .orElse(null);