8220493: Prepare Socket/ServerSocket for alternative platform SocketImpl

Co-authored-by: Michael McMahon <michael.x.mcmahon@oracle.com>
Reviewed-by: chegar

src/java.base/share/classes/java/net/DelegatingSocketImpl.java

@@ -0,0 +1,171 @@
+/*
+ * Copyright (c) 2019, 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 java.net;
+
+import java.io.FileDescriptor;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.util.Objects;
+import java.util.Set;
+
+import sun.net.PlatformSocketImpl;
+
+/**
+ * A SocketImpl that delegates all methods to another SocketImpl.
+ */
+
+class DelegatingSocketImpl extends SocketImpl {
+    protected final SocketImpl delegate;
+
+    DelegatingSocketImpl(SocketImpl delegate) {
+        assert delegate instanceof PlatformSocketImpl;
+        this.delegate = Objects.requireNonNull(delegate);
+    }
+
+    final SocketImpl delegate() {
+        return delegate;
+    }
+
+    @Override
+    protected FileDescriptor getFileDescriptor() {
+        return delegate.getFileDescriptor();
+    }
+
+    @Override
+    protected InetAddress getInetAddress() {
+        return delegate.getInetAddress();
+    }
+
+    @Override
+    protected int getPort() {
+        return delegate.getPort();
+    }
+
+    @Override
+    protected int getLocalPort() {
+        return delegate.getLocalPort();
+    }
+
+    @Override
+    protected void create(boolean stream) throws IOException {
+        delegate.create(stream);
+    }
+
+    @Override
+    protected void connect(String host, int port) throws IOException {
+        delegate.connect(host, port);
+    }
+
+    @Override
+    protected void connect(InetAddress address, int port) throws IOException {
+        delegate.connect(address, port);
+    }
+
+    @Override
+    protected void connect(SocketAddress address, int timeout) throws IOException {
+        delegate.connect(address, timeout);
+    }
+
+    @Override
+    protected void bind(InetAddress host, int port) throws IOException {
+        delegate.bind(host, port);
+    }
+
+    @Override
+    protected void listen(int backlog) throws IOException {
+        delegate.listen(backlog);
+    }
+
+    @Override
+    protected void accept(SocketImpl s) throws IOException {
+        delegate.accept(s);
+    }
+
+    @Override
+    protected InputStream getInputStream() throws IOException {
+        return delegate.getInputStream();
+    }
+
+    @Override
+    protected OutputStream getOutputStream() throws IOException {
+        return delegate.getOutputStream();
+    }
+
+    @Override
+    protected int available() throws IOException {
+        return delegate.available();
+    }
+
+    @Override
+    protected void close() throws IOException {
+        delegate.close();
+    }
+
+    @Override
+    protected boolean supportsUrgentData() {
+        return delegate.supportsUrgentData();
+    }
+
+    @Override
+    protected void sendUrgentData(int data) throws IOException {
+        delegate.sendUrgentData(data);
+    }
+
+    @Override
+    protected Set<SocketOption<?>> supportedOptions() {
+        return delegate.supportedOptions();
+    }
+
+    @Override
+    protected <T> void setOption(SocketOption<T> opt, T value) throws IOException {
+        delegate.setOption(opt, value);
+    }
+
+    @Override
+    protected <T> T getOption(SocketOption<T> opt) throws IOException {
+        return delegate.getOption(opt);
+    }
+
+    @Override
+    public void setOption(int optID, Object value) throws SocketException {
+        delegate.setOption(optID, value);
+    }
+
+    @Override
+    public Object getOption(int optID) throws SocketException {
+        return delegate.getOption(optID);
+    }
+
+    @Override
+    protected void shutdownInput() throws IOException {
+        delegate.shutdownInput();
+    }
+
+    @Override
+    protected void shutdownOutput() throws IOException {
+        delegate.shutdownOutput();
+    }
+}