Pass in a context with an optional logger and request object for additional context for the handler.

Author: robotdan

src/main/java/io/fusionauth/http/server/DefaultHTTPUnexpectedExceptionHandler.java

@@ -15,25 +15,14 @@
  */
 package io.fusionauth.http.server;
 
-import io.fusionauth.http.log.Logger;
-import io.fusionauth.http.log.LoggerFactory;
-
 /**
  * THe default HTTP unexpected exception handler.
  *
  * @author Daniel DeGroff
  */
 public class DefaultHTTPUnexpectedExceptionHandler implements HTTPUnexpectedExceptionHandler {
-  private final Logger logger;
-
-  public DefaultHTTPUnexpectedExceptionHandler(LoggerFactory loggerFactory) {
-    this.logger = loggerFactory.getLogger(DefaultHTTPUnexpectedExceptionHandler.class);
-  }
-
   @Override
-  public int handle(Throwable t) {
-    int internalServerError = 500;
-    logger.error(String.format("[%s] Closing socket with status [%d]. An HTTP worker threw an exception while processing a request.", Thread.currentThread().threadId(), internalServerError), t);
-    return internalServerError;
+  public void handle(ExceptionHandlerContext context) {
+    context.logger.error(String.format("[%s] Closing socket with status [%d]. An HTTP worker threw an exception while processing a request.", Thread.currentThread().threadId(), context.statusCode), context.throwable);
   }
 }

src/main/java/io/fusionauth/http/server/ExceptionHandlerContext.java

@@ -0,0 +1,40 @@
+/*
+ * Copyright (c) 2025, FusionAuth, All Rights Reserved
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
+ * either express or implied. See the License for the specific
+ * language governing permissions and limitations under the License.
+ */
+package io.fusionauth.http.server;
+
+import io.fusionauth.http.log.Logger;
+
+/**
+ * Provide context to the exception handler.
+ *
+ * @author Daniel DeGroff
+ */
+public class ExceptionHandlerContext {
+  public Logger logger;
+
+  public HTTPRequest request;
+
+  public int statusCode;
+
+  public Throwable throwable;
+
+  public ExceptionHandlerContext(Logger logger, HTTPRequest request, int statusCode, Throwable throwable) {
+    this.logger = logger;
+    this.request = request; // may be null
+    this.statusCode = statusCode;
+    this.throwable = throwable;
+  }
+}

src/main/java/io/fusionauth/http/server/HTTPServerConfiguration.java

@@ -79,7 +79,7 @@ public class HTTPServerConfiguration implements Configurable<HTTPServerConfigura
 
   private Duration shutdownDuration = Duration.ofSeconds(10);
 
-  private HTTPUnexpectedExceptionHandler unexpectedExceptionHandler;
+  private HTTPUnexpectedExceptionHandler unexpectedExceptionHandler = new DefaultHTTPUnexpectedExceptionHandler();
 
   private Duration writeThroughputCalculationDelayDuration = Duration.ofSeconds(5);
 
@@ -281,11 +281,6 @@ public Duration getShutdownDuration() {
    * @return The HTTP unexpected exception handler for this server. Never null.
    */
   public HTTPUnexpectedExceptionHandler getUnexpectedExceptionHandler() {
-    // Lazily construct a default so we can use the configured loggerFactory.
-    if (unexpectedExceptionHandler == null) {
-      unexpectedExceptionHandler = new DefaultHTTPUnexpectedExceptionHandler(loggerFactory);
-    }
-
     return unexpectedExceptionHandler;
   }
 

src/main/java/io/fusionauth/http/server/HTTPUnexpectedExceptionHandler.java

@@ -28,8 +28,7 @@ public interface HTTPUnexpectedExceptionHandler {
    * The intent is that this provides additional flexibility on the status code and the logging behavior when an unexpected exception
    * caught.
    *
-   * @param t the unexpected exception to handle.
-   * @return the desired HTTP status code. Note that if the response has already been committed this will be ignored.
+   * @param context the exception context
    */
-  int handle(Throwable t);
+  void handle(ExceptionHandlerContext context);
 }

src/main/java/io/fusionauth/http/server/internal/HTTPWorker.java

@@ -31,6 +31,7 @@
 import io.fusionauth.http.io.MultipartConfiguration;
 import io.fusionauth.http.io.PushbackInputStream;
 import io.fusionauth.http.log.Logger;
+import io.fusionauth.http.server.ExceptionHandlerContext;
 import io.fusionauth.http.server.HTTPHandler;
 import io.fusionauth.http.server.HTTPListenerConfiguration;
 import io.fusionauth.http.server.HTTPRequest;
@@ -104,6 +105,7 @@ public long getStartInstant() {
   @Override
   public void run() {
     HTTPInputStream httpInputStream;
+    HTTPRequest request = null;
     HTTPResponse response = null;
 
     try {
@@ -113,7 +115,7 @@ public void run() {
 
       while (true) {
         logger.trace("[{}] Running HTTP worker. Block while we wait to read the preamble", Thread.currentThread().threadId());
-        var request = new HTTPRequest(configuration.getContextPath(), listener.getCertificate() != null ? "https" : "http", listener.getPort(), socket.getInetAddress().getHostAddress());
+        request = new HTTPRequest(configuration.getContextPath(), listener.getCertificate() != null ? "https" : "http", listener.getPort(), socket.getInetAddress().getHostAddress());
 
         // Create a deep copy of the MultipartConfiguration so that the request may optionally modify the configuration on a per-request basis.
         request.getMultiPartStreamProcessor().setMultipartConfiguration(new MultipartConfiguration(configuration.getMultipartConfiguration()));
@@ -268,14 +270,14 @@ public void run() {
       logger.debug(String.format("[%s] Closing socket with status [%d]. An IO exception was thrown during processing. These are pretty common.", Thread.currentThread().threadId(), Status.InternalServerError), e);
       closeSocketOnError(response, Status.InternalServerError);
     } catch (Throwable e) {
-      var status = Status.InternalServerError;
+      ExceptionHandlerContext context = new ExceptionHandlerContext(logger, request, Status.InternalServerError, e);
       try {
-        status = configuration.getUnexpectedExceptionHandler().handle(e);
+        configuration.getUnexpectedExceptionHandler().handle(context);
       } catch (Throwable ignore) {
       }
 
       // Signal an error
-      closeSocketOnError(response, status);
+      closeSocketOnError(response, context.statusCode);
     } finally {
       if (instrumenter != null) {
         instrumenter.workerStopped();