src/jdk.httpserver/share/classes/com/sun/net/httpserver/spi/HttpServerProvider.java
changeset 47216 71c04702a3d5
parent 37782 ad8fe7507ecc
child 58514 270fdb5898f2
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/jdk.httpserver/share/classes/com/sun/net/httpserver/spi/HttpServerProvider.java	Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,179 @@
+/*
+ * 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.spi;
+
+import java.io.IOException;
+import java.net.*;
+import java.security.AccessController;
+import java.security.PrivilegedAction;
+import java.util.Iterator;
+import java.util.ServiceLoader;
+import java.util.ServiceConfigurationError;
+import com.sun.net.httpserver.*;
+
+/**
+ * Service provider class for HttpServer.
+ * Sub-classes of HttpServerProvider provide an implementation of
+ * {@link HttpServer} and associated classes. Applications do not normally use
+ * this class. See {@link #provider()} for how providers are found and loaded.
+ */
+public abstract class HttpServerProvider {
+
+    /**
+     * creates a HttpServer from this provider
+     *
+     * @param  addr
+     *         the address to bind to. May be {@code null}
+     *
+     * @param  backlog
+     *         the socket backlog. A value of {@code zero} means the systems default
+     */
+    public abstract HttpServer createHttpServer(InetSocketAddress addr,
+                                                int backlog)
+        throws IOException;
+
+    /**
+     * creates a HttpsServer from this provider
+     *
+     * @param  addr
+     *         the address to bind to. May be {@code null}
+     *
+     * @param  backlog
+     *         the socket backlog. A value of {@code zero} means the systems default
+     */
+    public abstract HttpsServer createHttpsServer(InetSocketAddress addr,
+                                                  int backlog)
+        throws IOException;
+
+    private static final Object lock = new Object();
+    private static HttpServerProvider provider = null;
+
+    /**
+     * Initializes a new instance of this class.
+     *
+     * @throws  SecurityException
+     *          If a security manager has been installed and it denies
+     *          {@link RuntimePermission}{@code ("httpServerProvider")}
+     */
+    protected HttpServerProvider() {
+        SecurityManager sm = System.getSecurityManager();
+        if (sm != null)
+            sm.checkPermission(new RuntimePermission("httpServerProvider"));
+    }
+
+    private static boolean loadProviderFromProperty() {
+        String cn = System.getProperty("com.sun.net.httpserver.HttpServerProvider");
+        if (cn == null)
+            return false;
+        try {
+            @SuppressWarnings("deprecation")
+            Object o = Class.forName(cn, true,
+                                     ClassLoader.getSystemClassLoader()).newInstance();
+            provider = (HttpServerProvider)o;
+            return true;
+        } catch (ClassNotFoundException |
+                 IllegalAccessException |
+                 InstantiationException |
+                 SecurityException x) {
+            throw new ServiceConfigurationError(null, x);
+        }
+    }
+
+    private static boolean loadProviderAsService() {
+        Iterator<HttpServerProvider> i =
+            ServiceLoader.load(HttpServerProvider.class,
+                               ClassLoader.getSystemClassLoader())
+                .iterator();
+        for (;;) {
+            try {
+                if (!i.hasNext())
+                    return false;
+                provider = i.next();
+                return true;
+            } catch (ServiceConfigurationError sce) {
+                if (sce.getCause() instanceof SecurityException) {
+                    // Ignore the security exception, try the next provider
+                    continue;
+                }
+                throw sce;
+            }
+        }
+    }
+
+    /**
+     * Returns the system wide default HttpServerProvider for this invocation of
+     * the Java virtual machine.
+     *
+     * <p> The first invocation of this method locates the default provider
+     * object as follows: </p>
+     *
+     * <ol>
+     *
+     *   <li><p> If the system property
+     *   {@code com.sun.net.httpserver.HttpServerProvider} is defined then it
+     *   is taken to be the fully-qualified name of a concrete provider class.
+     *   The class is loaded and instantiated; if this process fails then an
+     *   unspecified unchecked error or exception is thrown.  </p></li>
+     *
+     *   <li><p> If a provider class has been installed in a jar file that is
+     *   visible to the system class loader, and that jar file contains a
+     *   provider-configuration file named
+     *   {@code com.sun.net.httpserver.HttpServerProvider} in the resource
+     *   directory {@code META-INF/services}, then the first class name
+     *   specified in that file is taken.  The class is loaded and
+     *   instantiated; if this process fails then an unspecified unchecked error
+     *   or exception is thrown.  </p></li>
+     *
+     *   <li><p> Finally, if no provider has been specified by any of the above
+     *   means then the system-default provider class is instantiated and the
+     *   result is returned.  </p></li>
+     *
+     * </ol>
+     *
+     * <p> Subsequent invocations of this method return the provider that was
+     * returned by the first invocation.  </p>
+     *
+     * @return  The system-wide default HttpServerProvider
+     */
+    public static HttpServerProvider provider () {
+        synchronized (lock) {
+            if (provider != null)
+                return provider;
+            return (HttpServerProvider)AccessController
+                .doPrivileged(new PrivilegedAction<Object>() {
+                        public Object run() {
+                            if (loadProviderFromProperty())
+                                return provider;
+                            if (loadProviderAsService())
+                                return provider;
+                            provider = new sun.net.httpserver.DefaultHttpServerProvider();
+                            return provider;
+                        }
+                    });
+        }
+    }
+
+}