https://openjdk.java.net/ 
/*
 * Copyright (c) 2005, 2006, 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.net.*;
import java.io.*;
import java.nio.*;
import java.security.*;
import java.nio.channels.*;
import java.util.*;
import java.util.concurrent.*;
import javax.net.ssl.*;
import com.sun.net.httpserver.spi.HttpServerProvider;


This class implements a simple HTTP server. A HttpServer is bound to an IP address and port number and listens for incoming TCP connections from clients on this address. The sub-class HttpsServer implements a server which handles HTTPS requests. 
 One or more HttpHandler objects must be associated with a server in order to process requests. Each such HttpHandler is registered with a root URI path which represents the location of the application or service on this server. The mapping of a handler to a HttpServer is encapsulated by a HttpContext object. HttpContexts are created by calling createContext(String, HttpHandler). Any request for which no handler can be found is rejected with a 404 response. Management of threads can be done external to this object by providing a Executor object. If none is provided a default implementation is used. 


Mapping request URIs to HttpContext paths

When a HTTP request is received,
the appropriate HttpContext (and handler) is located by finding the context
whose path is the longest matching prefix of the request URI's path.
Paths are matched literally, which means that the strings are compared
case sensitively, and with no conversion to or from any encoded forms.
For example. Given a HttpServer with the following HttpContexts configured.




ContextContext path


ctx1"/"


ctx2"/apps/"


ctx3"/apps/foo/"





the following table shows some request URIs and which, if any context they would
match with.




Request URIMatches context


"http://foo.com/apps/foo/bar"ctx3


"http://foo.com/apps/Foo/bar"no match, wrong case


"http://foo.com/apps/app1"ctx2


"http://foo.com/foo"ctx1





Note about socket backlogs

When binding to an address and port number, the application can also specify an integer
backlog parameter. This represents the maximum number of incoming TCP connections
which the system will queue internally. Connections are queued while they are waiting to
be accepted by the HttpServer. When the limit is reached, further connections may be
rejected (or possibly ignored) by the underlying TCP implementation. Setting the right
backlog value is a compromise between efficient resource usage in the TCP layer (not setting
it too high) and allowing adequate throughput of incoming requests (not setting it too low).

Since:1.6
/**
 * This class implements a simple HTTP server. A HttpServer is bound to an IP address
 * and port number and listens for incoming TCP connections from clients on this address.
 * The sub-class {@link HttpsServer} implements a server which handles HTTPS requests.
 * <p>
 * One or more {@link HttpHandler} objects must be associated with a server
 * in order to process requests. Each such HttpHandler is registered
 * with a root URI path which represents the
 * location of the application or service on this server. The mapping of a handler
 * to a HttpServer is encapsulated by a {@link HttpContext} object. HttpContexts
 * are created by calling {@link #createContext(String,HttpHandler)}.
 * Any request for which no handler can be found is rejected with a 404 response.
 * Management of threads can be done external to this object by providing a
 * {@link java.util.concurrent.Executor} object. If none is provided a default
 * implementation is used.
 * <p>
 * <a name="mapping_description"></a>
 * <b>Mapping request URIs to HttpContext paths</b><p>
 * When a HTTP request is received,
 * the appropriate HttpContext (and handler) is located by finding the context
 * whose path is the longest matching prefix of the request URI's path.
 * Paths are matched literally, which means that the strings are compared
 * case sensitively, and with no conversion to or from any encoded forms.
 * For example. Given a HttpServer with the following HttpContexts configured.<p>
 * <table >
 * <tr><td><i>Context</i></td><td><i>Context path</i></td></tr>
 * <tr><td>ctx1</td><td>"/"</td></tr>
 * <tr><td>ctx2</td><td>"/apps/"</td></tr>
 * <tr><td>ctx3</td><td>"/apps/foo/"</td></tr>
 * </table>
 * <p>
 * the following table shows some request URIs and which, if any context they would
 * match with.<p>
 * <table>
 * <tr><td><i>Request URI</i></td><td><i>Matches context</i></td></tr>
 * <tr><td>"http://foo.com/apps/foo/bar"</td><td>ctx3</td></tr>
 * <tr><td>"http://foo.com/apps/Foo/bar"</td><td>no match, wrong case</td></tr>
 * <tr><td>"http://foo.com/apps/app1"</td><td>ctx2</td></tr>
 * <tr><td>"http://foo.com/foo"</td><td>ctx1</td></tr>
 * </table>
 * <p>
 * <b>Note about socket backlogs</b><p>
 * When binding to an address and port number, the application can also specify an integer
 * <i>backlog</i> parameter. This represents the maximum number of incoming TCP connections
 * which the system will queue internally. Connections are queued while they are waiting to
 * be accepted by the HttpServer. When the limit is reached, further connections may be
 * rejected (or possibly ignored) by the underlying TCP implementation. Setting the right
 * backlog value is a compromise between efficient resource usage in the TCP layer (not setting
 * it too high) and allowing adequate throughput of incoming requests (not setting it too low).
 * @since 1.6
 */

public abstract class HttpServer {

    /**
     */
    protected HttpServer () {
    }

    
creates a HttpServer instance which is initially not bound to any local address/port. The HttpServer is acquired from the currently installed HttpServerProvider The server must be bound using bind(InetSocketAddress, int) before it can be used. 
Throws:
/**
     * creates a HttpServer instance which is initially not bound to any local address/port.
     * The HttpServer is acquired from the currently installed {@link HttpServerProvider}
     * The server must be bound using {@link #bind(InetSocketAddress,int)} before it can be used.
     * @throws IOException
     */
    public static HttpServer create () throws IOException {
        return create (null, 0);
    }

    
Create a HttpServer instance which will bind to the specified InetSocketAddress (IP address and port number) A maximum backlog can also be specified. This is the maximum number of queued incoming connections to allow on the listening socket. Queued TCP connections exceeding this limit may be rejected by the TCP implementation. The HttpServer is acquired from the currently installed HttpServerProvider 
Params:
  • addr – the address to listen on, if null then bind() must be called
 to set the address
  • backlog – the socket backlog. If this value is less than or equal to zero,
         then a system default value is used.
Throws:
  • BindException – if the server cannot bind to the requested address,
         or if the server is already bound.
  • IOException – 
/**
     * Create a <code>HttpServer</code> instance which will bind to the
     * specified {@link java.net.InetSocketAddress} (IP address and port number)
     *
     * A maximum backlog can also be specified. This is the maximum number of
     * queued incoming connections to allow on the listening socket.
     * Queued TCP connections exceeding this limit may be rejected by the TCP implementation.
     * The HttpServer is acquired from the currently installed {@link HttpServerProvider}
     *
     * @param addr the address to listen on, if <code>null</code> then bind() must be called
     *  to set the address
     * @param backlog the socket backlog. If this value is less than or equal to zero,
     *          then a system default value is used.
     * @throws BindException if the server cannot bind to the requested address,
     *          or if the server is already bound.
     * @throws IOException
     */

    public static HttpServer create (
        InetSocketAddress addr, int backlog
    ) throws IOException {
        HttpServerProvider provider = HttpServerProvider.provider();
        return provider.createHttpServer (addr, backlog);
    }

    
Binds a currently unbound HttpServer to the given address and port number.
A maximum backlog can also be specified. This is the maximum number of
queued incoming connections to allow on the listening socket.
Queued TCP connections exceeding this limit may be rejected by the TCP implementation.

Params:
  • addr – the address to listen on
  • backlog – the socket backlog. If this value is less than or equal to zero,
         then a system default value is used.
Throws:
/**
     * Binds a currently unbound HttpServer to the given address and port number.
     * A maximum backlog can also be specified. This is the maximum number of
     * queued incoming connections to allow on the listening socket.
     * Queued TCP connections exceeding this limit may be rejected by the TCP implementation.
     * @param addr the address to listen on
     * @param backlog the socket backlog. If this value is less than or equal to zero,
     *          then a system default value is used.
     * @throws BindException if the server cannot bind to the requested address or if the server
     *          is already bound.
     * @throws NullPointerException if addr is <code>null</code>
     */
    public abstract void bind (InetSocketAddress addr, int backlog) throws IOException;

    
Starts this server in a new background thread. The background thread
inherits the priority, thread group and context class loader
of the caller.

/**
     * Starts this server in a new background thread. The background thread
     * inherits the priority, thread group and context class loader
     * of the caller.
     */
    public abstract void start () ;

    
sets this server's Executor object. An Executor must be established before start() is called. All HTTP requests are handled in tasks given to the executor. If this method is not called (before start()) or if it is called with a null Executor, then a default implementation is used, which uses the thread which was created by the start() method. 
Params:
  • executor – the Executor to set, or null for  default
         implementation
Throws:
/**
     * sets this server's {@link java.util.concurrent.Executor} object. An
     * Executor must be established before {@link #start()} is called.
     * All HTTP requests are handled in tasks given to the executor.
     * If this method is not called (before start()) or if it is
     * called with a <code>null</code> Executor, then
     * a default implementation is used, which uses the thread
     * which was created by the {@link #start()} method.
     * @param executor the Executor to set, or <code>null</code> for  default
     *          implementation
     * @throws IllegalStateException if the server is already started
     */
    public abstract void setExecutor (Executor executor);


    
returns this server's Executor object if one was specified with setExecutor(Executor), or null if none was
specified.

Returns:the Executor established for this server or null if not set.
/**
     * returns this server's Executor object if one was specified with
     * {@link #setExecutor(Executor)}, or <code>null</code> if none was
     * specified.
     * @return the Executor established for this server or <code>null</code> if not set.
     */
    public abstract Executor getExecutor () ;

    
stops this server by closing the listening socket and disallowing
any new exchanges from being processed. The method will then block
until all current exchange handlers have completed or else when
approximately delay seconds have elapsed (whichever happens
sooner). Then, all open TCP connections are closed, the background
thread created by start() exits, and the method returns.
Once stopped, a HttpServer cannot be re-used. 


Params:
  • delay – the maximum time in seconds to wait until exchanges have finished.
Throws:
/**
     * stops this server by closing the listening socket and disallowing
     * any new exchanges from being processed. The method will then block
     * until all current exchange handlers have completed or else when
     * approximately <i>delay</i> seconds have elapsed (whichever happens
     * sooner). Then, all open TCP connections are closed, the background
     * thread created by start() exits, and the method returns.
     * Once stopped, a HttpServer cannot be re-used. <p>
     *
     * @param delay the maximum time in seconds to wait until exchanges have finished.
     * @throws IllegalArgumentException if delay is less than zero.
     */
    public abstract void stop (int delay);

    
Creates a HttpContext. A HttpContext represents a mapping from a URI path to a exchange handler on this HttpServer. Once created, all requests received by the server for the path will be handled by calling the given handler object. The context is identified by the path, and can later be removed from the server using this with the removeContext(String) method. 

The path specifies the root URI path for this context. The first character of path must be
'/'. 

The class overview describes how incoming request URIs are mapped
to HttpContext instances.

Params:
  • path – the root URI path to associate the context with
  • handler – the handler to invoke for incoming requests.
Throws:
/**
     * Creates a HttpContext. A HttpContext represents a mapping from a
     * URI path to a exchange handler on this HttpServer. Once created, all requests
     * received by the server for the path will be handled by calling
     * the given handler object. The context is identified by the path, and
     * can later be removed from the server using this with the {@link #removeContext(String)} method.
     * <p>
     * The path specifies the root URI path for this context. The first character of path must be
     * '/'. <p>
     * The class overview describes how incoming request URIs are <a href="#mapping_description">mapped</a>
     * to HttpContext instances.
     * @param path the root URI path to associate the context with
     * @param handler the handler to invoke for incoming requests.
     * @throws IllegalArgumentException if path is invalid, or if a context
     *          already exists for this path
     * @throws NullPointerException if either path, or handler are <code>null</code>
     */
    public abstract HttpContext createContext (String path, HttpHandler handler) ;

    
Creates a HttpContext without initially specifying a handler. The handler must later be specified using HttpContext.setHandler(HttpHandler). A HttpContext represents a mapping from a URI path to an exchange handler on this HttpServer. Once created, and when the handler has been set, all requests received by the server for the path will be handled by calling the handler object. The context is identified by the path, and can later be removed from the server using this with the removeContext(String) method. 

The path specifies the root URI path for this context. The first character of path must be
'/'. 

The class overview describes how incoming request URIs are mapped
to HttpContext instances.

Params:
  • path – the root URI path to associate the context with
Throws:
/**
     * Creates a HttpContext without initially specifying a handler. The handler must later be specified using
     * {@link HttpContext#setHandler(HttpHandler)}.  A HttpContext represents a mapping from a
     * URI path to an exchange handler on this HttpServer. Once created, and when
     * the handler has been set, all requests
     * received by the server for the path will be handled by calling
     * the handler object. The context is identified by the path, and
     * can later be removed from the server using this with the {@link #removeContext(String)} method.
     * <p>
     * The path specifies the root URI path for this context. The first character of path must be
     * '/'. <p>
     * The class overview describes how incoming request URIs are <a href="#mapping_description">mapped</a>
     * to HttpContext instances.
     * @param path the root URI path to associate the context with
     * @throws IllegalArgumentException if path is invalid, or if a context
     *          already exists for this path
     * @throws NullPointerException if path is <code>null</code>
     */
    public abstract HttpContext createContext (String path) ;

    
Removes the context identified by the given path from the server.
Removing a context does not affect exchanges currently being processed
but prevents new ones from being accepted.

Params:
  • path – the path of the handler to remove
Throws:
/**
     * Removes the context identified by the given path from the server.
     * Removing a context does not affect exchanges currently being processed
     * but prevents new ones from being accepted.
     * @param path the path of the handler to remove
     * @throws IllegalArgumentException if no handler corresponding to this
     *          path exists.
     * @throws NullPointerException if path is <code>null</code>
     */
    public abstract void removeContext (String path) throws IllegalArgumentException ;

    
Removes the given context from the server.
Removing a context does not affect exchanges currently being processed
but prevents new ones from being accepted.

Params:
  • context – the context to remove
Throws:
/**
     * Removes the given context from the server.
     * Removing a context does not affect exchanges currently being processed
     * but prevents new ones from being accepted.
     * @param context the context to remove
     * @throws NullPointerException if context is <code>null</code>
     */
    public abstract void removeContext (HttpContext context) ;

    
returns the address this server is listening on

Returns:the address/port number the server is listening on
/**
     * returns the address this server is listening on
     * @return the address/port number the server is listening on
     */
    public abstract InetSocketAddress getAddress() ;
}