Use ByteBuffer support in ServletHttpHandlerAdapter

As of Servlet 6.1, the `ServletInputStream` and `ServletOutputStream`
offer read and write variants based on `ByteBuffer` instead of byte
arrays. This can improve performance and avoid memory copy for I/O
calls.

This was already partially supported for some servers like Tomcat
through specific adapters. This commit moves this support to the
standard `ServletHttpHandlerAdapter` and makes it available for all
Servlet 6.1+ containers.

Closes gh-33748

spring-web/src/main/java/org/springframework/http/server/reactive/JettyHttpHandlerAdapter.java

@@ -1,83 +0,0 @@
-/*
- * Copyright 2002-2024 the original author or authors.
- *
- * 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
- *
- *      https://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 org.springframework.http.server.reactive;
-
-import java.io.IOException;
-import java.io.OutputStream;
-import java.nio.ByteBuffer;
-
-import jakarta.servlet.AsyncContext;
-import jakarta.servlet.http.HttpServletResponse;
-import org.eclipse.jetty.ee10.servlet.HttpOutput;
-
-import org.springframework.core.io.buffer.DataBuffer;
-import org.springframework.core.io.buffer.DataBufferFactory;
-
-/**
- * {@link ServletHttpHandlerAdapter} extension that uses Jetty APIs for writing
- * to the response with {@link ByteBuffer}.
- *
- * @author Violeta Georgieva
- * @author Brian Clozel
- * @author Juergen Hoeller
- * @since 5.0
- * @see org.springframework.web.server.adapter.AbstractReactiveWebInitializer
- */
-public class JettyHttpHandlerAdapter extends ServletHttpHandlerAdapter {
-
-	public JettyHttpHandlerAdapter(HttpHandler httpHandler) {
-		super(httpHandler);
-	}
-
-
-	@Override
-	protected ServletServerHttpResponse createResponse(HttpServletResponse response,
-			AsyncContext context, ServletServerHttpRequest request) throws IOException {
-
-		return new Jetty12ServerHttpResponse(
-				response, context, getDataBufferFactory(), getBufferSize(), request);
-	}
-
-
-	private static final class Jetty12ServerHttpResponse extends ServletServerHttpResponse {
-
-		Jetty12ServerHttpResponse(HttpServletResponse response, AsyncContext asyncContext,
-				DataBufferFactory bufferFactory, int bufferSize, ServletServerHttpRequest request)
-				throws IOException {
-
-			super(response, asyncContext, bufferFactory, bufferSize, request);
-		}
-
-		@Override
-		protected int writeToOutputStream(DataBuffer dataBuffer) throws IOException {
-			OutputStream output = getOutputStream();
-			if (output instanceof HttpOutput httpOutput) {
-				int len = 0;
-				try (DataBuffer.ByteBufferIterator iterator = dataBuffer.readableByteBuffers()) {
-					while (iterator.hasNext() && httpOutput.isReady()) {
-						ByteBuffer byteBuffer = iterator.next();
-						len += byteBuffer.remaining();
-						httpOutput.write(byteBuffer);
-					}
-				}
-				return len;
-			}
-			return super.writeToOutputStream(dataBuffer);
-		}
-	}
-
-}

spring-web/src/main/java/org/springframework/http/server/reactive/ServletServerHttpRequest.java

@@ -20,6 +20,7 @@ import java.io.IOException;
 import java.net.InetSocketAddress;
 import java.net.URI;
 import java.net.URISyntaxException;
+import java.nio.ByteBuffer;
 import java.nio.charset.Charset;
 import java.security.cert.X509Certificate;
 import java.util.Enumeration;
@@ -38,6 +39,7 @@ import reactor.core.publisher.Flux;
 
 import org.springframework.core.io.buffer.DataBuffer;
 import org.springframework.core.io.buffer.DataBufferFactory;
+import org.springframework.core.io.buffer.DataBufferUtils;
 import org.springframework.core.io.buffer.DefaultDataBufferFactory;
 import org.springframework.http.HttpCookie;
 import org.springframework.http.HttpHeaders;
@@ -58,6 +60,7 @@ import org.springframework.web.util.UriComponentsBuilder;
  *
  * @author Rossen Stoyanchev
  * @author Juergen Hoeller
+ * @author Brian Clozel
  * @since 5.0
  */
 class ServletServerHttpRequest extends AbstractServerHttpRequest {
@@ -75,7 +78,7 @@ class ServletServerHttpRequest extends AbstractServerHttpRequest {
 
 	private final DataBufferFactory bufferFactory;
 
-	private final byte[] buffer;
+	private final int bufferSize;
 
 	private final AsyncListener asyncListener;
 
@@ -99,7 +102,7 @@ class ServletServerHttpRequest extends AbstractServerHttpRequest {
 
 		this.request = request;
 		this.bufferFactory = bufferFactory;
-		this.buffer = new byte[bufferSize];
+		this.bufferSize = bufferSize;
 
 		this.asyncListener = new RequestAsyncListener();
 
@@ -275,21 +278,32 @@ class ServletServerHttpRequest extends AbstractServerHttpRequest {
 	 * or {@link #EOF_BUFFER} if the input stream returned -1.
 	 */
 	DataBuffer readFromInputStream() throws IOException {
-		int read = this.inputStream.read(this.buffer);
+		DataBuffer dataBuffer = this.bufferFactory.allocateBuffer(this.bufferSize);
+		int read = -1;
+		try {
+			try (DataBuffer.ByteBufferIterator iterator = dataBuffer.writableByteBuffers()) {
+				Assert.state(iterator.hasNext(), "No ByteBuffer available");
+				ByteBuffer byteBuffer = iterator.next();
+				read = this.inputStream.read(byteBuffer);
+			}
 			logBytesRead(read);
-
 			if (read > 0) {
-			DataBuffer dataBuffer = this.bufferFactory.allocateBuffer(read);
-			dataBuffer.write(this.buffer, 0, read);
+				dataBuffer.writePosition(read);
 				return dataBuffer;
 			}
-
-		if (read == -1) {
+			else if (read == -1) {
 				return EOF_BUFFER;
 			}
-
+			else {
 				return AbstractListenerReadPublisher.EMPTY_BUFFER;
 			}
+		}
+		finally {
+			if (read <= 0) {
+				DataBufferUtils.release(dataBuffer);
+			}
+		}
+	}
 
 	protected final void logBytesRead(int read) {
 		Log rsReadLogger = AbstractListenerReadPublisher.rsReadLogger;

spring-web/src/main/java/org/springframework/http/server/reactive/ServletServerHttpResponse.java

@@ -17,7 +17,7 @@
 package org.springframework.http.server.reactive;
 
 import java.io.IOException;
-import java.io.InputStream;
+import java.nio.ByteBuffer;
 import java.nio.charset.Charset;
 
 import jakarta.servlet.AsyncContext;
@@ -45,6 +45,7 @@ import org.springframework.util.Assert;
  *
  * @author Rossen Stoyanchev
  * @author Juergen Hoeller
+ * @author Brian Clozel
  * @since 5.0
  */
 class ServletServerHttpResponse extends AbstractListenerServerHttpResponse {
@@ -222,15 +223,15 @@ class ServletServerHttpResponse extends AbstractListenerServerHttpResponse {
 	 */
 	protected int writeToOutputStream(DataBuffer dataBuffer) throws IOException {
 		ServletOutputStream outputStream = this.outputStream;
-		InputStream input = dataBuffer.asInputStream();
-		int bytesWritten = 0;
-		byte[] buffer = new byte[this.bufferSize];
-		int bytesRead;
-		while (outputStream.isReady() && (bytesRead = input.read(buffer)) != -1) {
-			outputStream.write(buffer, 0, bytesRead);
-			bytesWritten += bytesRead;
-		}
-		return bytesWritten;
+		int len = 0;
+		try (DataBuffer.ByteBufferIterator iterator = dataBuffer.readableByteBuffers()) {
+			while (iterator.hasNext() && outputStream.isReady()) {
+				ByteBuffer byteBuffer = iterator.next();
+				len += byteBuffer.remaining();
+				outputStream.write(byteBuffer);
+			}
+		}
+		return len;
 	}
 
 	private void flush() throws IOException {

spring-web/src/main/java/org/springframework/http/server/reactive/TomcatHttpHandlerAdapter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2023 the original author or authors.
+ * Copyright 2002-2024 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -26,16 +26,12 @@ import jakarta.servlet.http.HttpServletRequest;
 import jakarta.servlet.http.HttpServletRequestWrapper;
 import jakarta.servlet.http.HttpServletResponse;
 import jakarta.servlet.http.HttpServletResponseWrapper;
-import org.apache.catalina.connector.CoyoteInputStream;
-import org.apache.catalina.connector.CoyoteOutputStream;
 import org.apache.catalina.connector.RequestFacade;
 import org.apache.catalina.connector.ResponseFacade;
 import org.apache.coyote.Request;
 import org.apache.coyote.Response;
 
-import org.springframework.core.io.buffer.DataBuffer;
 import org.springframework.core.io.buffer.DataBufferFactory;
-import org.springframework.core.io.buffer.DataBufferUtils;
 import org.springframework.http.HttpHeaders;
 import org.springframework.util.Assert;
 import org.springframework.util.MultiValueMap;
@@ -81,10 +77,6 @@ public class TomcatHttpHandlerAdapter extends ServletHttpHandlerAdapter {
 
 		private static final Field COYOTE_REQUEST_FIELD;
 
-		private final int bufferSize;
-
-		private final DataBufferFactory factory;
-
 		static {
 			Field field = ReflectionUtils.findField(RequestFacade.class, "request");
 			Assert.state(field != null, "Incompatible Tomcat implementation");
@@ -97,8 +89,6 @@ public class TomcatHttpHandlerAdapter extends ServletHttpHandlerAdapter {
 				throws IOException, URISyntaxException {
 
 			super(createTomcatHttpHeaders(request), request, context, servletPath, factory, bufferSize);
-			this.factory = factory;
-			this.bufferSize = bufferSize;
 		}
 
 		private static MultiValueMap<String, String> createTomcatHttpHeaders(HttpServletRequest request) {
@@ -124,41 +114,6 @@ public class TomcatHttpHandlerAdapter extends ServletHttpHandlerAdapter {
 			}
 		}
 
-		@Override
-		protected DataBuffer readFromInputStream() throws IOException {
-			if (getInputStream() instanceof CoyoteInputStream coyoteInputStream) {
-				DataBuffer dataBuffer = this.factory.allocateBuffer(this.bufferSize);
-				int read = -1;
-				try {
-					try (DataBuffer.ByteBufferIterator iterator = dataBuffer.writableByteBuffers()) {
-						Assert.state(iterator.hasNext(), "No ByteBuffer available");
-						ByteBuffer byteBuffer = iterator.next();
-						read = coyoteInputStream.read(byteBuffer);
-					}
-					logBytesRead(read);
-					if (read > 0) {
-						dataBuffer.writePosition(read);
-						return dataBuffer;
-					}
-					else if (read == -1) {
-						return EOF_BUFFER;
-					}
-					else {
-						return AbstractListenerReadPublisher.EMPTY_BUFFER;
-					}
-				}
-				finally {
-					if (read <= 0) {
-						DataBufferUtils.release(dataBuffer);
-					}
-				}
-			}
-			else {
-				// It's possible InputStream can be wrapped, preventing use of CoyoteInputStream
-				return super.readFromInputStream();
-			}
-
-		}
 	}
 
 
@@ -208,23 +163,6 @@ public class TomcatHttpHandlerAdapter extends ServletHttpHandlerAdapter {
 			adaptHeaders(true);
 		}
 
-		@Override
-		protected int writeToOutputStream(DataBuffer dataBuffer) throws IOException {
-			if (getOutputStream() instanceof CoyoteOutputStream coyoteOutputStream) {
-				int len = 0;
-				try (DataBuffer.ByteBufferIterator iterator = dataBuffer.readableByteBuffers()) {
-					while (iterator.hasNext() && coyoteOutputStream.isReady()) {
-						ByteBuffer byteBuffer = iterator.next();
-						len += byteBuffer.remaining();
-						coyoteOutputStream.write(byteBuffer);
-					}
-				}
-				return len;
-			}
-			else {
-				return super.writeToOutputStream(dataBuffer);
-			}
-		}
 	}
 
 }

spring-web/src/testFixtures/java/org/springframework/web/testfixture/http/server/reactive/bootstrap/JettyHttpServer.java

@@ -22,7 +22,6 @@ import org.eclipse.jetty.ee10.websocket.server.config.JettyWebSocketServletConta
 import org.eclipse.jetty.server.Server;
 import org.eclipse.jetty.server.ServerConnector;
 
-import org.springframework.http.server.reactive.JettyHttpHandlerAdapter;
 import org.springframework.http.server.reactive.ServletHttpHandlerAdapter;
 
 /**
@@ -41,7 +40,7 @@ public class JettyHttpServer extends AbstractHttpServer {
 
 		this.jettyServer = new Server();
 
-		ServletHttpHandlerAdapter servlet = createServletAdapter();
+		ServletHttpHandlerAdapter servlet = new ServletHttpHandlerAdapter(resolveHttpHandler());
 		ServletHolder servletHolder = new ServletHolder(servlet);
 		servletHolder.setAsyncSupported(true);
 
@@ -56,10 +55,6 @@ public class JettyHttpServer extends AbstractHttpServer {
 		this.jettyServer.setHandler(this.contextHandler);
 	}
 
-	private ServletHttpHandlerAdapter createServletAdapter() {
-		return new JettyHttpHandlerAdapter(resolveHttpHandler());
-	}
-
 	@Override
 	protected void startInternal() throws Exception {
 		this.jettyServer.start();