add event handler class

src/main/java/com/stripe/StripeClient.java

@@ -41,6 +41,50 @@ protected StripeResponseGetter getResponseGetter() {
     return responseGetter;
   }
 
+  /**
+   * Gets the current StripeContext from the client's configuration.
+   *
+   * @return the current StripeContext, or null if none is set
+   */
+  protected String getContext() {
+    // TODO(major): add getOptions to the StripeResponseGetter interface? that would simplify this
+    if (!(responseGetter instanceof LiveStripeResponseGetter)) {
+      return null;
+    }
+
+    LiveStripeResponseGetter liveGetter = (LiveStripeResponseGetter) responseGetter;
+    StripeResponseGetterOptions options = liveGetter.getOptions();
+
+    return options.getStripeContext();
+  }
+
+  /**
+   * Sets the StripeContext for this client. This updates the client configuration to use the
+   * provided context for all subsequent requests.
+   */
+  protected void setContext(String context) {
+    // TODO(major): add getOptions to the StripeResponseGetter interface? that would simplify this
+    if (!(responseGetter instanceof LiveStripeResponseGetter)) {
+      throw new IllegalStateException(
+          "Cannot set context on a StripeClient with a non-Live response getter");
+    }
+
+    LiveStripeResponseGetter liveGetter = (LiveStripeResponseGetter) responseGetter;
+    StripeResponseGetterOptions options = liveGetter.getOptions();
+
+    if (!(options instanceof ClientStripeResponseGetterOptions)) {
+      throw new IllegalStateException(
+          "Cannot set context on a StripeClient with non-standard options");
+    }
+
+    ClientStripeResponseGetterOptions clientOptions = (ClientStripeResponseGetterOptions) options;
+    clientOptions.setStripeContext(context);
+  }
+
+  protected void setContext(StripeContext context) {
+    setContext(context.toString());
+  }
+
   /**
    * Returns an StripeEvent instance using the provided JSON payload. Throws a JsonSyntaxException
    * if the payload is not valid JSON, and a SignatureVerificationException if the signature
@@ -1073,7 +1117,7 @@ static class ClientStripeResponseGetterOptions extends StripeResponseGetterOptio
     private final String stripeAccount;
 
     @Getter(onMethod_ = {@Override})
-    private final String stripeContext;
+    private volatile String stripeContext;
 
     ClientStripeResponseGetterOptions(
         Authenticator authenticator,
@@ -1103,6 +1147,15 @@ static class ClientStripeResponseGetterOptions extends StripeResponseGetterOptio
       this.stripeAccount = stripeAccount;
       this.stripeContext = stripeContext;
     }
+
+    /**
+     * Updates the stripe context.
+     *
+     * @param stripeContext the new stripe context value
+     */
+    protected void setStripeContext(String stripeContext) {
+      this.stripeContext = stripeContext;
+    }
   }
 
   /**
@@ -1412,4 +1465,9 @@ public StripeResponse rawRequest(
   public StripeObject deserialize(String rawJson, ApiMode apiMode) throws StripeException {
     return StripeObject.deserializeStripeObject(rawJson, this.getResponseGetter(), apiMode);
   }
+
+  public StripeEventRouter router(
+      String webhookSecret, StripeEventRouter.UnhandledEventHandler handler) {
+    return new StripeEventRouter(webhookSecret, this, handler);
+  }
 }

src/main/java/com/stripe/StripeContext.java

@@ -64,8 +64,8 @@ public StripeContext pop() {
   /**
    * Converts the context to a string by joining segments with '/'.
    *
-   * @return string representation of the context segments joined by '/', `null` if there are no
-   *     segments (useful for clearing context)
+   * @return string representation of the context segments joined by '/'. If there are no segments,
+   *     returns an empty string (useful for clearing context).
    */
   @Override
   public String toString() {