Added documentation to migrate from Servlet to Handler.
Introduced CompletableTask to simplify Content.Source reads. Signed-off-by: Simone Bordet <simone.bordet@gmail.com>
This commit is contained in:
Simone Bordet
parent
b126407c4e
commit
8f6a38aca8
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@ -97,8 +97,52 @@
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[[pg-migration-11-to-12-servlet-to-handler]]
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==== Migrate Servlets to Jetty Handlers
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Web applications written using the Servlet APIs may be re-written using the Jetty `Handler` APIs.
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The sections below outline the Jetty `Handler` APIs that correspond to the Servlet APIs.
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To replace the functionalities of Servlet Filters, refer to xref:pg-server-http-handler[this section].
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===== Handler Request APIs
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[source,java,indent=0]
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----
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include::../{doc_code}/org/eclipse/jetty/docs/programming/migration/ServletToHandlerDocs.java[tags=request]
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----
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===== Handler Request Content APIs
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[source,java,indent=0]
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----
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include::../{doc_code}/org/eclipse/jetty/docs/programming/migration/ServletToHandlerDocs.java[tags=requestContent-string]
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include::../{doc_code}/org/eclipse/jetty/docs/programming/migration/ServletToHandlerDocs.java[tags=requestContent-buffer]
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include::../{doc_code}/org/eclipse/jetty/docs/programming/migration/ServletToHandlerDocs.java[tags=requestContent-stream]
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include::../{doc_code}/org/eclipse/jetty/docs/programming/migration/ServletToHandlerDocs.java[tags=requestContent-source]
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----
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===== Handler Response APIs
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[source,java,indent=0]
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----
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include::../{doc_code}/org/eclipse/jetty/docs/programming/migration/ServletToHandlerDocs.java[tags=response]
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----
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===== Handler Response Content APIs
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[source,java,indent=0]
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----
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include::../{doc_code}/org/eclipse/jetty/docs/programming/migration/ServletToHandlerDocs.java[tags=responseContent-implicit]
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include::../{doc_code}/org/eclipse/jetty/docs/programming/migration/ServletToHandlerDocs.java[tags=responseContent-implicit-status]
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include::../{doc_code}/org/eclipse/jetty/docs/programming/migration/ServletToHandlerDocs.java[tags=responseContent-explicit]
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include::../{doc_code}/org/eclipse/jetty/docs/programming/migration/ServletToHandlerDocs.java[tags=responseContent-content]
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include::../{doc_code}/org/eclipse/jetty/docs/programming/migration/ServletToHandlerDocs.java[tags=responseContent-string]
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include::../{doc_code}/org/eclipse/jetty/docs/programming/migration/ServletToHandlerDocs.java[tags=responseContent-echo]
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include::../{doc_code}/org/eclipse/jetty/docs/programming/migration/ServletToHandlerDocs.java[tags=responseContent-trailers]
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----
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[[pg-migration-11-to-12-api-changes]]
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==== APIs Changes
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@ -0,0 +1,643 @@
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//
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// ========================================================================
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// Copyright (c) 1995 Mort Bay Consulting Pty Ltd and others.
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//
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// This program and the accompanying materials are made available under the
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// terms of the Eclipse Public License v. 2.0 which is available at
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// https://www.eclipse.org/legal/epl-2.0, or the Apache License, Version 2.0
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// which is available at https://www.apache.org/licenses/LICENSE-2.0.
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//
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// SPDX-License-Identifier: EPL-2.0 OR Apache-2.0
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// ========================================================================
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//
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package org.eclipse.jetty.docs.programming.migration;
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import java.io.InputStream;
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import java.nio.ByteBuffer;
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import java.time.Duration;
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import java.util.List;
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import java.util.Locale;
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import java.util.Map;
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import java.util.Set;
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import java.util.function.Supplier;
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import org.eclipse.jetty.http.HttpCookie;
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import org.eclipse.jetty.http.HttpFields;
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import org.eclipse.jetty.http.HttpHeader;
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import org.eclipse.jetty.http.HttpStatus;
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import org.eclipse.jetty.http.Trailers;
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import org.eclipse.jetty.io.Content;
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import org.eclipse.jetty.server.Context;
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import org.eclipse.jetty.server.Handler;
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import org.eclipse.jetty.server.Request;
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import org.eclipse.jetty.server.Response;
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import org.eclipse.jetty.server.Session;
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import org.eclipse.jetty.util.Callback;
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import org.eclipse.jetty.util.CompletableTask;
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import org.eclipse.jetty.util.Fields;
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import org.eclipse.jetty.util.Promise;
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import static java.nio.charset.StandardCharsets.UTF_8;
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@SuppressWarnings("unused")
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public class ServletToHandlerDocs
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{
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@SuppressWarnings("InnerClassMayBeStatic")
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// tag::request[]
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public class RequestAPIs extends Handler.Abstract
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{
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@Override
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public boolean handle(Request request, Response response, Callback callback) throws Exception
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{
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// Gets the request method.
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// Replaces:
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// - servletRequest.getMethod();
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String method = request.getMethod();
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// Gets the request protocol name and version.
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// Replaces:
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// - servletRequest.getProtocol();
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String protocol = request.getConnectionMetaData().getProtocol();
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// Gets the full request URI.
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// Replaces:
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// - servletRequest.getRequestURL();
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String fullRequestURI = request.getHttpURI().asString();
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// Gets the request context.
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// Replaces:
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// - servletRequest.getServletContext()
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Context context = request.getContext();
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// Gets the context path.
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// Replaces:
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// - servletRequest.getContextPath()
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String contextPath = context.getContextPath();
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// Gets the request path.
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// Replaces:
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// - servletRequest.getRequestURI();
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String requestPath = request.getHttpURI().getPath();
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// Gets the request path after the context path.
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// Replaces:
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// - servletRequest.getServletPath() + servletRequest.getPathInfo()
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String pathInContext = Request.getPathInContext(request);
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// Gets the request query.
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// Replaces:
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// - servletRequest.getQueryString()
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String queryString = request.getHttpURI().getQuery();
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// Gets request parameters.
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// Replaces:
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// - servletRequest.getParameterNames();
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// - servletRequest.getParameter(name);
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// - servletRequest.getParameterValues(name);
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// - servletRequest.getParameterMap();
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Fields queryParameters = Request.extractQueryParameters(request, UTF_8);
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Fields allParameters = Request.getParameters(request);
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// Gets cookies.
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// Replaces:
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// - servletRequest.getCookies();
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List<HttpCookie> cookies = Request.getCookies(request);
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// Gets request HTTP headers.
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// Replaces:
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// - servletRequest.getHeaderNames()
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// - servletRequest.getHeader(name)
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// - servletRequest.getHeaders(name)
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// - servletRequest.getDateHeader(name)
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// - servletRequest.getIntHeader(name)
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HttpFields requestHeaders = request.getHeaders();
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// Gets the request Content-Type.
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// Replaces:
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// - servletRequest.getContentType()
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String contentType = request.getHeaders().get(HttpHeader.CONTENT_TYPE);
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// Gets the request Content-Length.
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// Replaces:
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// - servletRequest.getContentLength()
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// - servletRequest.getContentLengthLong()
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long contentLength = request.getHeaders().getLongField(HttpHeader.CONTENT_LENGTH);
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// Gets the request locales.
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// Replaces:
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// - servletRequest.getLocale()
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// - servletRequest.getLocales()
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List<Locale> locales = Request.getLocales(request);
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// Gets the request scheme.
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// Replaces:
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// - servletRequest.getScheme()
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String scheme = request.getHttpURI().getScheme();
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// Gets the server name.
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// Replaces:
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// - servletRequest.getServerName()
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String serverName = Request.getServerName(request);
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// Gets the server port.
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// Replaces:
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// - servletRequest.getServerPort()
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int serverPort = Request.getServerPort(request);
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// Gets the remote host/address.
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// Replaces:
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// - servletRequest.getRemoteAddr()
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// - servletRequest.getRemoteHost()
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String remoteAddress = Request.getRemoteAddr(request);
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// Gets the remote port.
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// Replaces:
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// - servletRequest.getRemotePort()
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int remotePort = Request.getRemotePort(request);
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// Gets the local host/address.
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// Replaces:
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// - servletRequest.getLocalAddr()
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// - servletRequest.getLocalHost()
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String localAddress = Request.getLocalAddr(request);
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// Gets the local port.
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// Replaces:
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// - servletRequest.getLocalPort()
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int localPort = Request.getLocalPort(request);
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// Gets the request attributes.
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// Replaces:
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// - servletRequest.getAttributeNames()
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// - servletRequest.getAttribute(name)
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// - servletRequest.setAttribute(name, value)
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// - servletRequest.removeAttribute(name)
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String name = "name";
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Object value = "value";
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Set<String> names = request.getAttributeNameSet();
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Object attribute = request.getAttribute(name);
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request.setAttribute(name, value);
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request.removeAttribute(name);
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request.clearAttributes();
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Map<String, Object> map = request.asAttributeMap();
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// Gets the request trailers.
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// Replaces:
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// - servletRequest.getTrailerFields()
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HttpFields trailers = request.getTrailers();
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// Gets the HTTP session.
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// Replaces:
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// - servletRequest.getSession()
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// - servletRequest.getSession(create)
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boolean create = true;
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Session session = request.getSession(create);
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callback.succeeded();
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return false;
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}
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}
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// end::request[]
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@SuppressWarnings("InnerClassMayBeStatic")
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public class RequestContentAPIsString extends Handler.Abstract
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{
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// tag::requestContent-string[]
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@Override
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public boolean handle(Request request, Response response, Callback callback) throws Exception
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{
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// Non-blocking read the request content as a String.
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// Use with caution as the request content may be large.
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Promise.Completable<String> completable = new Promise.Completable<>();
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Content.Source.asString(request, UTF_8, completable);
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completable.whenComplete((requestContent, failure) ->
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{
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if (failure == null)
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{
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// Process the request content here.
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// Implicitly respond with status code 200 and no content.
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callback.succeeded();
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}
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else
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{
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// Implicitly respond with status code 500.
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callback.failed(failure);
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}
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});
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return true;
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}
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// end::requestContent-string[]
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}
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@SuppressWarnings("InnerClassMayBeStatic")
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public class RequestContentAPIsByteBuffer extends Handler.Abstract
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{
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// tag::requestContent-buffer[]
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@Override
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public boolean handle(Request request, Response response, Callback callback) throws Exception
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{
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// Non-blocking read the request content as a ByteBuffer.
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// Use with caution as the request content may be large.
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Promise.Completable<ByteBuffer> completable = new Promise.Completable<>();
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Content.Source.asByteBuffer(request, completable);
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completable.whenComplete((requestContent, failure) ->
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{
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if (failure == null)
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{
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// Process the request content here.
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// Implicitly respond with status code 200 and no content.
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callback.succeeded();
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}
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else
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{
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// Implicitly respond with status code 500.
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callback.failed(failure);
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}
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});
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return true;
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}
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// end::requestContent-buffer[]
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}
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@SuppressWarnings("InnerClassMayBeStatic")
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public class RequestContentAPIsInputStream extends Handler.Abstract
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{
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// tag::requestContent-stream[]
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@Override
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public boolean handle(Request request, Response response, Callback callback) throws Exception
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{
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// Read the request content as an InputStream.
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// Note that InputStream.read() may block.
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try (InputStream inputStream = Content.Source.asInputStream(request))
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{
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while (true)
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{
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int read = inputStream.read();
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// EOF was reached, stop reading.
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if (read < 0)
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break;
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// Process the read byte here.
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}
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}
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// Implicitly respond with status code 200 and no content.
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callback.succeeded();
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return true;
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}
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// end::requestContent-stream[]
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}
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@SuppressWarnings("InnerClassMayBeStatic")
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public class RequestContentAPIsSource extends Handler.Abstract
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{
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// tag::requestContent-source[]
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@Override
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public boolean handle(Request request, Response response, Callback callback) throws Exception
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{
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CompletableTask<Void> reader = new CompletableTask<>()
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{
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@Override
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public void run()
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{
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// Read in a loop.
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while (true)
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{
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// Read a chunk of content.
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Content.Chunk chunk = request.read();
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// If there is no content, demand to be
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// called back when more content is available.
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if (chunk == null)
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{
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request.demand(this);
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return;
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}
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// If a failure is read, complete with a failure.
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if (Content.Chunk.isFailure(chunk))
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{
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Throwable failure = chunk.getFailure();
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completeExceptionally(failure);
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return;
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}
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if (chunk instanceof Trailers trailers)
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{
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// Possibly process the request trailers here.
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// Trailers have an empty ByteBuffer and are a last chunk.
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}
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// Process the request content chunk here.
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// After the processing, the chunk MUST be released.
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chunk.release();
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// If the last chunk is read, complete normally.
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if (chunk.isLast())
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{
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complete(null);
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return;
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}
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// Not the last chunk of content, loop around to read more.
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}
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}
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};
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// Initiate the read of the request content.
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reader.start();
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// When the read is complete, complete the Handler callback.
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callback.completeWith(reader);
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return true;
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}
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// end::requestContent-source[]
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}
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@SuppressWarnings("InnerClassMayBeStatic")
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// tag::response[]
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public class ResponseAPIs extends Handler.Abstract
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{
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@Override
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public boolean handle(Request request, Response response, Callback callback) throws Exception
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{
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// Sets/Gets the response HTTP status.
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// Replaces:
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// - servletResponse.setStatus(code);
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// - servletResponse.getStatus();
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response.setStatus(HttpStatus.OK_200);
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int status = response.getStatus();
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// Gets the response HTTP headers.
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// Replaces:
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// - servletResponse.setHeader(name, value);
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// - servletResponse.addHeader(name, value);
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// - servletResponse.setDateHeader(name, date);
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// - servletResponse.addDateHeader(name, date);
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// - servletResponse.setIntHeader(name, value);
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// - servletResponse.addIntHeader(name, value);
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// - servletResponse.getHeaderNames()
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// - servletResponse.getHeader(name)
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// - servletResponse.getHeaders(name)
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// - servletResponse.containsHeader(name)
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HttpFields.Mutable responseHeaders = response.getHeaders();
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// Sets an HTTP cookie.
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// Replaces:
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// - servletResponse.addCookie(cookie);
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HttpCookie cookie = HttpCookie.build("name", "value")
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.domain("example.org")
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.path("/path")
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.maxAge(Duration.ofDays(1).toSeconds())
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.build();
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Response.addCookie(response, cookie);
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// Sets the response Content-Type.
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// Replaces:
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// - servletResponse.setContentType(type)
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responseHeaders.put(HttpHeader.CONTENT_TYPE, "text/plain; charset=UTF-8");
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// Sets the response Content-Length.
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// Replaces:
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// - servletResponse.setContentLength(length)
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// - servletResponse.setContentLengthLong(length)
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responseHeaders.put(HttpHeader.CONTENT_LENGTH, 1024L);
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// Sets/Gets the response trailers.
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// Replaces:
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// - servletResponse.setTrailerFields(() -> trailers)
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// - servletResponse.getTrailerFields()
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HttpFields trailers = HttpFields.build().put("checksum", 0xCAFE);
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response.setTrailersSupplier(trailers);
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Supplier<HttpFields> trailersSupplier = response.getTrailersSupplier();
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// Gets whether the response is committed.
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// Replaces:
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// - servletResponse.isCommitted()
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boolean committed = response.isCommitted();
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// Resets the response.
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// Replaces:
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// - servletResponse.reset();
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response.reset();
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// Sends a redirect response.
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// Replaces:
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// - servletResponse.encodeRedirectURL(location)
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// - servletResponse.sendRedirect(location)
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String location = Request.toRedirectURI(request, "/redirect");
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Response.sendRedirect(request, response, callback, location);
|
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// Sends an error response.
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// Replaces:
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// - servletResponse.sendError(code);
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// - servletResponse.sendError(code, message);
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Response.writeError(request, response, callback, HttpStatus.SERVICE_UNAVAILABLE_503, "Request Cannot be Processed");
|
||||
|
||||
callback.succeeded();
|
||||
return true;
|
||||
}
|
||||
}
|
||||
// end::response[]
|
||||
|
||||
@SuppressWarnings("InnerClassMayBeStatic")
|
||||
public class ResponseContentAPIsImplicit extends Handler.Abstract
|
||||
{
|
||||
// tag::responseContent-implicit[]
|
||||
@Override
|
||||
public boolean handle(Request request, Response response, Callback callback) throws Exception
|
||||
{
|
||||
// Produces an implicit response with status code 200
|
||||
// with no content when returning from this method.
|
||||
|
||||
// The Handler callback must be completed when returning true.
|
||||
callback.succeeded();
|
||||
return true;
|
||||
}
|
||||
// end::responseContent-implicit[]
|
||||
}
|
||||
|
||||
@SuppressWarnings("InnerClassMayBeStatic")
|
||||
public class ResponseContentAPIsImplicitWithStatus extends Handler.Abstract
|
||||
{
|
||||
// tag::responseContent-implicit-status[]
|
||||
@Override
|
||||
public boolean handle(Request request, Response response, Callback callback) throws Exception
|
||||
{
|
||||
// Produces an implicit response with status 204
|
||||
// with no content when returning from this method.
|
||||
response.setStatus(HttpStatus.NO_CONTENT_204);
|
||||
|
||||
// The Handler callback must be completed when returning true.
|
||||
callback.succeeded();
|
||||
return true;
|
||||
}
|
||||
// end::responseContent-implicit-status[]
|
||||
}
|
||||
|
||||
@SuppressWarnings("InnerClassMayBeStatic")
|
||||
public class ResponseContentAPIsExplicit extends Handler.Abstract
|
||||
{
|
||||
// tag::responseContent-explicit[]
|
||||
@Override
|
||||
public boolean handle(Request request, Response response, Callback callback) throws Exception
|
||||
{
|
||||
// Produces an explicit response with status 204 with no content.
|
||||
response.setStatus(HttpStatus.NO_CONTENT_204);
|
||||
|
||||
// This explicit first write() writes the response status code and headers.
|
||||
// It is also the last write (as specified by the first parameter)
|
||||
// and writes an empty content (the second parameter, a null ByteBuffer).
|
||||
// When this write completes, the Handler callback is completed.
|
||||
response.write(true, null, callback);
|
||||
|
||||
return true;
|
||||
}
|
||||
// end::responseContent-explicit[]
|
||||
}
|
||||
|
||||
@SuppressWarnings("InnerClassMayBeStatic")
|
||||
public class ResponseContentAPISimpleContent extends Handler.Abstract
|
||||
{
|
||||
// tag::responseContent-content[]
|
||||
@Override
|
||||
public boolean handle(Request request, Response response, Callback callback) throws Exception
|
||||
{
|
||||
response.setStatus(HttpStatus.OK_200);
|
||||
|
||||
ByteBuffer content = UTF_8.encode("Hello World");
|
||||
|
||||
// Explicit first write that writes the response status code, headers and content.
|
||||
// When this write completes, the Handler callback is completed.
|
||||
response.write(true, content, callback);
|
||||
|
||||
return true;
|
||||
}
|
||||
// end::responseContent-content[]
|
||||
}
|
||||
|
||||
@SuppressWarnings("InnerClassMayBeStatic")
|
||||
public class ResponseContentAPIFlush extends Handler.Abstract
|
||||
{
|
||||
// tag::responseContent-content[]
|
||||
@Override
|
||||
public boolean handle(Request request, Response response, Callback callback) throws Exception
|
||||
{
|
||||
response.setStatus(HttpStatus.OK_200);
|
||||
|
||||
ByteBuffer content = UTF_8.encode("Hello World");
|
||||
response.getHeaders().put(HttpHeader.CONTENT_LENGTH, content.remaining());
|
||||
|
||||
// Flush the response status code and the headers (no content).
|
||||
// This is the fist but non-last write.
|
||||
Callback.Completable completable = new Callback.Completable();
|
||||
response.write(false, null, completable);
|
||||
|
||||
// When the first write completes, perform the second (and last) write.
|
||||
completable.whenComplete((ignored, failure) ->
|
||||
{
|
||||
if (failure == null)
|
||||
{
|
||||
// Now explicitly write the content as the last write.
|
||||
// When this write completes, the Handler callback is completed.
|
||||
response.write(true, content, callback);
|
||||
}
|
||||
else
|
||||
{
|
||||
// Implicitly respond with status code 500.
|
||||
callback.failed(failure);
|
||||
}
|
||||
});
|
||||
|
||||
return true;
|
||||
}
|
||||
// end::responseContent-content[]
|
||||
}
|
||||
|
||||
@SuppressWarnings("InnerClassMayBeStatic")
|
||||
public class ResponseContentAPIString extends Handler.Abstract
|
||||
{
|
||||
// tag::responseContent-string[]
|
||||
@Override
|
||||
public boolean handle(Request request, Response response, Callback callback) throws Exception
|
||||
{
|
||||
response.setStatus(HttpStatus.OK_200);
|
||||
|
||||
// Utility method to write UTF-8 string content.
|
||||
// When this write completes, the Handler callback is completed.
|
||||
Content.Sink.write(response, true, "Hello World", callback);
|
||||
|
||||
return true;
|
||||
}
|
||||
// end::responseContent-string[]
|
||||
}
|
||||
|
||||
@SuppressWarnings("InnerClassMayBeStatic")
|
||||
public class ResponseContentAPIEcho extends Handler.Abstract
|
||||
{
|
||||
// tag::responseContent-echo[]
|
||||
@Override
|
||||
public boolean handle(Request request, Response response, Callback callback) throws Exception
|
||||
{
|
||||
response.setStatus(HttpStatus.OK_200);
|
||||
|
||||
// Utility method to echo the content from the request to the response.
|
||||
// When the echo completes, the Handler callback is completed.
|
||||
Content.copy(request, response, callback);
|
||||
|
||||
return true;
|
||||
}
|
||||
// end::responseContent-echo[]
|
||||
}
|
||||
|
||||
@SuppressWarnings("InnerClassMayBeStatic")
|
||||
public class ResponseContentAPITrailers extends Handler.Abstract
|
||||
{
|
||||
// tag::responseContent-trailers[]
|
||||
@Override
|
||||
public boolean handle(Request request, Response response, Callback callback) throws Exception
|
||||
{
|
||||
response.setStatus(HttpStatus.OK_200);
|
||||
|
||||
// The trailers must be set on the response before the first write.
|
||||
HttpFields.Mutable trailers = HttpFields.build();
|
||||
response.setTrailersSupplier(trailers);
|
||||
|
||||
// Explicit first write that writes the response status code, headers and content.
|
||||
// The trailers have not been written yet; they will be written with the last write.
|
||||
ByteBuffer content = UTF_8.encode("Hello World");
|
||||
Callback.Completable completable = new Callback.Completable();
|
||||
response.write(false, content, completable);
|
||||
|
||||
completable.whenComplete((ignored, failure) ->
|
||||
{
|
||||
if (failure == null)
|
||||
{
|
||||
// Update the trailers
|
||||
trailers.put("Content-Checksum", 0xCAFE);
|
||||
|
||||
// Explicit last write to write the trailers
|
||||
// and complete the Handler callback.
|
||||
response.write(true, null, callback);
|
||||
}
|
||||
else
|
||||
{
|
||||
// Implicitly respond with status code 500.
|
||||
callback.failed(failure);
|
||||
}
|
||||
});
|
||||
|
||||
return true;
|
||||
}
|
||||
// end::responseContent-trailers[]
|
||||
}
|
||||
}
|
||||
|
|
@ -42,6 +42,7 @@ import org.eclipse.jetty.io.content.PathContentSource;
|
|||
import org.eclipse.jetty.toolchain.test.MavenTestingUtils;
|
||||
import org.eclipse.jetty.util.BufferUtil;
|
||||
import org.eclipse.jetty.util.Callback;
|
||||
import org.eclipse.jetty.util.CompletableTask;
|
||||
import org.eclipse.jetty.util.FutureCallback;
|
||||
import org.eclipse.jetty.util.FuturePromise;
|
||||
import org.eclipse.jetty.util.IO;
|
||||
|
|
@ -104,7 +105,9 @@ public class ContentSourceTest
|
|||
return List.of(asyncSource, byteBufferSource, transformerSource, pathSource, inputSource, inputSource2);
|
||||
}
|
||||
|
||||
/** Get the next chunk, blocking if necessary
|
||||
/**
|
||||
* Get the next chunk, blocking if necessary
|
||||
*
|
||||
* @param source The source to get the next chunk from
|
||||
* @return A non null chunk
|
||||
*/
|
||||
|
|
@ -113,8 +116,7 @@ public class ContentSourceTest
|
|||
Content.Chunk chunk = source.read();
|
||||
if (chunk != null)
|
||||
return chunk;
|
||||
FuturePromise<Content.Chunk> next = new FuturePromise<>();
|
||||
Runnable getNext = new Runnable()
|
||||
CompletableTask<Content.Chunk> task = new CompletableTask<>()
|
||||
{
|
||||
@Override
|
||||
public void run()
|
||||
|
|
@ -122,18 +124,12 @@ public class ContentSourceTest
|
|||
Content.Chunk chunk = source.read();
|
||||
if (chunk == null)
|
||||
source.demand(this);
|
||||
next.succeeded(chunk);
|
||||
else
|
||||
complete(chunk);
|
||||
}
|
||||
};
|
||||
source.demand(getNext);
|
||||
try
|
||||
{
|
||||
return next.get();
|
||||
}
|
||||
catch (Exception e)
|
||||
{
|
||||
throw new RuntimeException(e);
|
||||
}
|
||||
source.demand(task);
|
||||
return task.join();
|
||||
}
|
||||
|
||||
@ParameterizedTest
|
||||
|
|
@ -141,8 +137,7 @@ public class ContentSourceTest
|
|||
public void testRead(Content.Source source) throws Exception
|
||||
{
|
||||
StringBuilder builder = new StringBuilder();
|
||||
CountDownLatch eof = new CountDownLatch(1);
|
||||
source.demand(new Runnable()
|
||||
var task = new CompletableTask<>()
|
||||
{
|
||||
@Override
|
||||
public void run()
|
||||
|
|
@ -162,14 +157,14 @@ public class ContentSourceTest
|
|||
|
||||
if (chunk.isLast())
|
||||
{
|
||||
eof.countDown();
|
||||
complete(null);
|
||||
break;
|
||||
}
|
||||
}
|
||||
}
|
||||
});
|
||||
|
||||
assertTrue(eof.await(10, TimeUnit.SECONDS));
|
||||
};
|
||||
source.demand(task);
|
||||
task.get(10, TimeUnit.SECONDS);
|
||||
assertThat(builder.toString(), is("onetwo"));
|
||||
}
|
||||
|
||||
|
|
|
|||
|
|
@ -0,0 +1,76 @@
|
|||
//
|
||||
// ========================================================================
|
||||
// Copyright (c) 1995 Mort Bay Consulting Pty Ltd and others.
|
||||
//
|
||||
// This program and the accompanying materials are made available under the
|
||||
// terms of the Eclipse Public License v. 2.0 which is available at
|
||||
// https://www.eclipse.org/legal/epl-2.0, or the Apache License, Version 2.0
|
||||
// which is available at https://www.apache.org/licenses/LICENSE-2.0.
|
||||
//
|
||||
// SPDX-License-Identifier: EPL-2.0 OR Apache-2.0
|
||||
// ========================================================================
|
||||
//
|
||||
|
||||
package org.eclipse.jetty.util;
|
||||
|
||||
import java.util.concurrent.CompletableFuture;
|
||||
|
||||
/**
|
||||
* <p>A {@link CompletableFuture} that implements {@link Runnable} to perform
|
||||
* a one-shot task that eventually completes this {@link CompletableFuture}.</p>
|
||||
* <p>Subclasses override {@link #run()} to implement the task.</p>
|
||||
* <p>Users of this class start the task execution via {@link #start()}.</p>
|
||||
* <p>Typical usage:</p>
|
||||
* <pre>{@code
|
||||
* CompletableTask<T> task = new CompletableTask<>()
|
||||
* {
|
||||
* @Override
|
||||
* public void run()
|
||||
* {
|
||||
* try
|
||||
* {
|
||||
* // Perform some task.
|
||||
* T result = performTask();
|
||||
*
|
||||
* // Eventually complete this CompletableFuture.
|
||||
* complete(result);
|
||||
* }
|
||||
* catch (Throwable x)
|
||||
* {
|
||||
* completeExceptionally(x);
|
||||
* }
|
||||
* }
|
||||
* }
|
||||
*
|
||||
* // Start the task and then process the
|
||||
* // result of the task when it is complete.
|
||||
* task.start()
|
||||
* .whenComplete((result, failure) ->
|
||||
* {
|
||||
* if (failure == null)
|
||||
* {
|
||||
* // The task completed successfully.
|
||||
* }
|
||||
* else
|
||||
* {
|
||||
* // The task failed.
|
||||
* }
|
||||
* });
|
||||
* }</pre>
|
||||
*
|
||||
* @param <T> the type of the result of the task
|
||||
*/
|
||||
public abstract class CompletableTask<T> extends CompletableFuture<T> implements Runnable
|
||||
{
|
||||
/**
|
||||
* <p>Starts the task by calling {@link #run()}
|
||||
* and returns this {@link CompletableTask}.</p>
|
||||
*
|
||||
* @return this {@link CompletableTask}
|
||||
*/
|
||||
public CompletableTask<T> start()
|
||||
{
|
||||
run();
|
||||
return this;
|
||||
}
|
||||
}
|
||||
Loading…
Reference in New Issue