src/jdk.httpserver/share/classes/com/sun/net/httpserver/HttpExchange.java
changeset 47216 71c04702a3d5
parent 34894 3248b89d1921
child 53720 3e451bff6f7f
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/jdk.httpserver/share/classes/com/sun/net/httpserver/HttpExchange.java	Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,264 @@
+/*
+ * Copyright (c) 2005, 2013, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+package com.sun.net.httpserver;
+
+import java.io.*;
+import java.nio.*;
+import java.nio.channels.*;
+import java.net.*;
+import javax.net.ssl.*;
+import java.util.*;
+
+/**
+ * This class encapsulates a HTTP request received and a
+ * response to be generated in one exchange. It provides methods
+ * for examining the request from the client, and for building and
+ * sending the response.
+ * <p>
+ * The typical life-cycle of a HttpExchange is shown in the sequence
+ * below.
+ * <ol><li>{@link #getRequestMethod()} to determine the command
+ * <li>{@link #getRequestHeaders()} to examine the request headers (if needed)
+ * <li>{@link #getRequestBody()} returns a {@link java.io.InputStream} for reading the request body.
+ *     After reading the request body, the stream is close.
+ * <li>{@link #getResponseHeaders()} to set any response headers, except content-length
+ * <li>{@link #sendResponseHeaders(int,long)} to send the response headers. Must be called before
+ * next step.
+ * <li>{@link #getResponseBody()} to get a {@link java.io.OutputStream} to send the response body.
+ *      When the response body has been written, the stream must be closed to terminate the exchange.
+ * </ol>
+ * <b>Terminating exchanges</b>
+ * <br>
+ * Exchanges are terminated when both the request InputStream and response OutputStream are closed.
+ * Closing the OutputStream, implicitly closes the InputStream (if it is not already closed).
+ * However, it is recommended
+ * to consume all the data from the InputStream before closing it.
+ * The convenience method {@link #close()} does all of these tasks.
+ * Closing an exchange without consuming all of the request body is not an error
+ * but may make the underlying TCP connection unusable for following exchanges.
+ * The effect of failing to terminate an exchange is undefined, but will typically
+ * result in resources failing to be freed/reused.
+ * @since 1.6
+ */
+
+public abstract class HttpExchange {
+
+    protected HttpExchange () {
+    }
+
+    /**
+     * Returns an immutable Map containing the HTTP headers that were
+     * included with this request. The keys in this Map will be the header
+     * names, while the values will be a List of Strings containing each value
+     * that was included (either for a header that was listed several times,
+     * or one that accepts a comma-delimited list of values on a single line).
+     * In either of these cases, the values for the header name will be
+     * presented in the order that they were included in the request.
+     * <p>
+     * The keys in Map are case-insensitive.
+     * @return a read-only Map which can be used to access request headers
+     */
+    public abstract Headers getRequestHeaders () ;
+
+    /**
+     * Returns a mutable Map into which the HTTP response headers can be stored
+     * and which will be transmitted as part of this response. The keys in the
+     * Map will be the header names, while the values must be a List of Strings
+     * containing each value that should be included multiple times
+     * (in the order that they should be included).
+     * <p>
+     * The keys in Map are case-insensitive.
+     * @return a writable Map which can be used to set response headers.
+     */
+    public abstract Headers getResponseHeaders () ;
+
+    /**
+     * Get the request URI
+     *
+     * @return the request URI
+     */
+    public abstract URI getRequestURI () ;
+
+    /**
+     * Get the request method
+     * @return the request method
+     */
+    public abstract String getRequestMethod ();
+
+    /**
+     * Get the HttpContext for this exchange
+     * @return the HttpContext
+     */
+    public abstract HttpContext getHttpContext ();
+
+    /**
+     * Ends this exchange by doing the following in sequence:<ol>
+     * <li>close the request InputStream, if not already closed;</li>
+     * <li>close the response OutputStream, if not already closed.</li>
+     * </ol>
+     */
+    public abstract void close () ;
+
+    /**
+     * returns a stream from which the request body can be read.
+     * Multiple calls to this method will return the same stream.
+     * It is recommended that applications should consume (read) all of the
+     * data from this stream before closing it. If a stream is closed
+     * before all data has been read, then the close() call will
+     * read and discard remaining data (up to an implementation specific
+     * number of bytes).
+     * @return the stream from which the request body can be read.
+     */
+    public abstract InputStream getRequestBody () ;
+
+    /**
+     * returns a stream to which the response body must be
+     * written. {@link #sendResponseHeaders(int,long)}) must be called prior to calling
+     * this method. Multiple calls to this method (for the same exchange)
+     * will return the same stream. In order to correctly terminate
+     * each exchange, the output stream must be closed, even if no
+     * response body is being sent.
+     * <p>
+     * Closing this stream implicitly
+     * closes the InputStream returned from {@link #getRequestBody()}
+     * (if it is not already closed).
+     * <P>
+     * If the call to sendResponseHeaders() specified a fixed response
+     * body length, then the exact number of bytes specified in that
+     * call must be written to this stream. If too many bytes are written,
+     * then write() will throw an IOException. If too few bytes are written
+     * then the stream close() will throw an IOException. In both cases,
+     * the exchange is aborted and the underlying TCP connection closed.
+     * @return the stream to which the response body is written
+     */
+    public abstract OutputStream getResponseBody () ;
+
+
+    /**
+     * Starts sending the response back to the client using the current set of response headers
+     * and the numeric response code as specified in this method. The response body length is also specified
+     * as follows. If the response length parameter is greater than zero, this specifies an exact
+     * number of bytes to send and the application must send that exact amount of data.
+     * If the response length parameter is {@code zero}, then chunked transfer encoding is
+     * used and an arbitrary amount of data may be sent. The application terminates the
+     * response body by closing the OutputStream. If response length has the value {@code -1}
+     * then no response body is being sent.
+     * <p>
+     * If the content-length response header has not already been set then
+     * this is set to the appropriate value depending on the response length parameter.
+     * <p>
+     * This method must be called prior to calling {@link #getResponseBody()}.
+     * @param rCode the response code to send
+     * @param responseLength if {@literal > 0}, specifies a fixed response
+     *        body length and that exact number of bytes must be written
+     *        to the stream acquired from getResponseBody(), or else
+     *        if equal to 0, then chunked encoding is used,
+     *        and an arbitrary number of bytes may be written.
+     *        if {@literal <= -1}, then no response body length is specified and
+     *        no response body may be written.
+     * @see HttpExchange#getResponseBody()
+     */
+    public abstract void sendResponseHeaders (int rCode, long responseLength) throws IOException ;
+
+    /**
+     * Returns the address of the remote entity invoking this request
+     * @return the InetSocketAddress of the caller
+     */
+    public abstract InetSocketAddress getRemoteAddress ();
+
+    /**
+     * Returns the response code, if it has already been set
+     * @return the response code, if available. {@code -1} if not available yet.
+     */
+    public abstract int getResponseCode ();
+
+    /**
+     * Returns the local address on which the request was received
+     * @return the InetSocketAddress of the local interface
+     */
+    public abstract InetSocketAddress getLocalAddress ();
+
+    /**
+     * Returns the protocol string from the request in the form
+     * <i>protocol/majorVersion.minorVersion</i>. For example,
+     * "HTTP/1.1"
+     * @return the protocol string from the request
+     */
+    public abstract String getProtocol ();
+
+    /**
+     * Filter modules may store arbitrary objects with HttpExchange
+     * instances as an out-of-band communication mechanism. Other Filters
+     * or the exchange handler may then access these objects.
+     * <p>
+     * Each Filter class will document the attributes which they make
+     * available.
+     * @param name the name of the attribute to retrieve
+     * @return the attribute object, or null if it does not exist
+     * @throws NullPointerException if name is {@code null}
+     */
+    public abstract Object getAttribute (String name) ;
+
+    /**
+     * Filter modules may store arbitrary objects with HttpExchange
+     * instances as an out-of-band communication mechanism. Other Filters
+     * or the exchange handler may then access these objects.
+     * <p>
+     * Each Filter class will document the attributes which they make
+     * available.
+     * @param name the name to associate with the attribute value
+     * @param value the object to store as the attribute value. {@code null}
+     * value is permitted.
+     * @throws NullPointerException if name is {@code null}
+     */
+    public abstract void setAttribute (String name, Object value) ;
+
+    /**
+     * Used by Filters to wrap either (or both) of this exchange's InputStream
+     * and OutputStream, with the given filtered streams so
+     * that subsequent calls to {@link #getRequestBody()} will
+     * return the given {@link java.io.InputStream}, and calls to
+     * {@link #getResponseBody()} will return the given
+     * {@link java.io.OutputStream}. The streams provided to this
+     * call must wrap the original streams, and may be (but are not
+     * required to be) sub-classes of {@link java.io.FilterInputStream}
+     * and {@link java.io.FilterOutputStream}.
+     * @param i the filtered input stream to set as this object's inputstream,
+     *          or {@code null} if no change.
+     * @param o the filtered output stream to set as this object's outputstream,
+     *          or {@code null} if no change.
+     */
+    public abstract void setStreams (InputStream i, OutputStream o);
+
+
+    /**
+     * If an authenticator is set on the HttpContext that owns this exchange,
+     * then this method will return the {@link HttpPrincipal} that represents
+     * the authenticated user for this HttpExchange.
+     * @return the HttpPrincipal, or {@code null} if no authenticator is set.
+     */
+    public abstract HttpPrincipal getPrincipal ();
+}