/*
 * Copyright 2002-2018 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
 *
 *      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.
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package org.springframework.http.server.reactive;

import java.io.IOException;
import java.lang.reflect.Field;
import java.net.URISyntaxException;
import java.nio.ByteBuffer;
import java.nio.charset.Charset;
import javax.servlet.AsyncContext;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;
import javax.servlet.http.HttpServletResponse;
import javax.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.http.MediaType;
import org.springframework.util.Assert;
import org.springframework.util.ReflectionUtils;

ServletHttpHandlerAdapter extension that uses Tomcat APIs for reading from the request and writing to the response with ByteBuffer.
Author:Violeta Georgieva, Brian Clozel
See Also:
Since:5.0
/** * {@link ServletHttpHandlerAdapter} extension that uses Tomcat APIs for reading * from the request and writing to the response with {@link ByteBuffer}. * * @author Violeta Georgieva * @author Brian Clozel * @since 5.0 * @see org.springframework.web.server.adapter.AbstractReactiveWebInitializer */
public class TomcatHttpHandlerAdapter extends ServletHttpHandlerAdapter { public TomcatHttpHandlerAdapter(HttpHandler httpHandler) { super(httpHandler); } @Override protected ServletServerHttpRequest createRequest(HttpServletRequest request, AsyncContext asyncContext) throws IOException, URISyntaxException { Assert.notNull(getServletPath(), "Servlet path is not initialized"); return new TomcatServerHttpRequest( request, asyncContext, getServletPath(), getDataBufferFactory(), getBufferSize()); } @Override protected ServletServerHttpResponse createResponse(HttpServletResponse response, AsyncContext asyncContext, ServletServerHttpRequest request) throws IOException { return new TomcatServerHttpResponse( response, asyncContext, getDataBufferFactory(), getBufferSize(), request); } private static final class TomcatServerHttpRequest extends ServletServerHttpRequest { 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"); ReflectionUtils.makeAccessible(field); COYOTE_REQUEST_FIELD = field; } TomcatServerHttpRequest(HttpServletRequest request, AsyncContext context, String servletPath, DataBufferFactory factory, int bufferSize) throws IOException, URISyntaxException { super(createTomcatHttpHeaders(request), request, context, servletPath, factory, bufferSize); this.factory = factory; this.bufferSize = bufferSize; } private static HttpHeaders createTomcatHttpHeaders(HttpServletRequest request) { RequestFacade requestFacade = getRequestFacade(request); org.apache.catalina.connector.Request connectorRequest = (org.apache.catalina.connector.Request) ReflectionUtils.getField(COYOTE_REQUEST_FIELD, requestFacade); Assert.state(connectorRequest != null, "No Tomcat connector request"); Request tomcatRequest = connectorRequest.getCoyoteRequest(); TomcatHeadersAdapter headers = new TomcatHeadersAdapter(tomcatRequest.getMimeHeaders()); return new HttpHeaders(headers); } private static RequestFacade getRequestFacade(HttpServletRequest request) { if (request instanceof RequestFacade) { return (RequestFacade) request; } else if (request instanceof HttpServletRequestWrapper) { HttpServletRequestWrapper wrapper = (HttpServletRequestWrapper) request; HttpServletRequest wrappedRequest = (HttpServletRequest) wrapper.getRequest(); return getRequestFacade(wrappedRequest); } else { throw new IllegalArgumentException("Cannot convert [" + request.getClass() + "] to org.apache.catalina.connector.RequestFacade"); } } @Override protected DataBuffer readFromInputStream() throws IOException { boolean release = true; int capacity = this.bufferSize; DataBuffer dataBuffer = this.factory.allocateBuffer(capacity); try { ByteBuffer byteBuffer = dataBuffer.asByteBuffer(0, capacity); ServletRequest request = getNativeRequest(); int read = ((CoyoteInputStream) request.getInputStream()).read(byteBuffer); logBytesRead(read); if (read > 0) { dataBuffer.writePosition(read); release = false; return dataBuffer; } else if (read == -1) { return EOF_BUFFER; } else { return null; } } finally { if (release) { DataBufferUtils.release(dataBuffer); } } } } private static final class TomcatServerHttpResponse extends ServletServerHttpResponse { private static final Field COYOTE_RESPONSE_FIELD; static { Field field = ReflectionUtils.findField(ResponseFacade.class, "response"); Assert.state(field != null, "Incompatible Tomcat implementation"); ReflectionUtils.makeAccessible(field); COYOTE_RESPONSE_FIELD = field; } TomcatServerHttpResponse(HttpServletResponse response, AsyncContext context, DataBufferFactory factory, int bufferSize, ServletServerHttpRequest request) throws IOException { super(createTomcatHttpHeaders(response), response, context, factory, bufferSize, request); } private static HttpHeaders createTomcatHttpHeaders(HttpServletResponse response) { ResponseFacade responseFacade = getResponseFacade(response); org.apache.catalina.connector.Response connectorResponse = (org.apache.catalina.connector.Response) ReflectionUtils.getField(COYOTE_RESPONSE_FIELD, responseFacade); Assert.state(connectorResponse != null, "No Tomcat connector response"); Response tomcatResponse = connectorResponse.getCoyoteResponse(); TomcatHeadersAdapter headers = new TomcatHeadersAdapter(tomcatResponse.getMimeHeaders()); return new HttpHeaders(headers); } private static ResponseFacade getResponseFacade(HttpServletResponse response) { if (response instanceof ResponseFacade) { return (ResponseFacade) response; } else if (response instanceof HttpServletResponseWrapper) { HttpServletResponseWrapper wrapper = (HttpServletResponseWrapper) response; HttpServletResponse wrappedResponse = (HttpServletResponse) wrapper.getResponse(); return getResponseFacade(wrappedResponse); } else { throw new IllegalArgumentException("Cannot convert [" + response.getClass() + "] to org.apache.catalina.connector.ResponseFacade"); } } @Override protected void applyHeaders() { HttpServletResponse response = getNativeResponse(); MediaType contentType = getHeaders().getContentType(); if (response.getContentType() == null && contentType != null) { response.setContentType(contentType.toString()); } Charset charset = (contentType != null ? contentType.getCharset() : null); if (response.getCharacterEncoding() == null && charset != null) { response.setCharacterEncoding(charset.name()); } long contentLength = getHeaders().getContentLength(); if (contentLength != -1) { response.setContentLengthLong(contentLength); } } @Override protected int writeToOutputStream(DataBuffer dataBuffer) throws IOException { ByteBuffer input = dataBuffer.asByteBuffer(); int len = input.remaining(); ServletResponse response = getNativeResponse(); ((CoyoteOutputStream) response.getOutputStream()).write(input); return len; } } }