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 *
 * Redistributions of source code must retain the above copyright notice, this
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 *
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package org.hsqldb.server;

import java.lang.reflect.Constructor;
import java.lang.reflect.InvocationTargetException;
import java.net.InetAddress;
import java.net.ServerSocket;
import java.net.Socket;

Base class for producing the Socket objects used by HSQLDB.
Author:
Blaine Simpson (blaine dot simpson at admc dot com), Campbell Burnet (campbell-burnet@users dot sourceforge.net)
Version:
2.3.0
Since:
1.7.2/**
 * Base class for producing the Socket objects used by HSQLDB.
 *
 * @author Blaine Simpson (blaine dot simpson at admc dot com)
 * @author Campbell Burnet (campbell-burnet@users dot sourceforge.net)
 * @version 2.3.0
 * @since 1.7.2
 */
public class HsqlSocketFactory {

// ----------------------------- static members ---------------------------------
    private static HsqlSocketFactory plainImpl;
    private static HsqlSocketFactory sslImpl;

// ------------------------------ constructors ---------------------------------

    
External construction disabled.  New factory instances are retrieved
through the newHsqlSocketFactory method instead.
/**
     * External construction disabled.  New factory instances are retrieved
     * through the newHsqlSocketFactory method instead.
     */
    protected HsqlSocketFactory() throws Exception {}

// ------------------------- factory builder method ----------------------------

    
Retrieves an HsqlSocketFactory whose subclass and attributes are
determined by the specified argument, tls.
Params:
tls – whether to retrieve a factory producing SSL sockets
Throws:
Exception – if the new factory cannot be constructed or is
     of the wrong type
Returns:
a new factory/**
     * Retrieves an HsqlSocketFactory whose subclass and attributes are
     * determined by the specified argument, tls.
     *
     * @param tls whether to retrieve a factory producing SSL sockets
     * @throws Exception if the new factory cannot be constructed or is
     *      of the wrong type
     * @return a new factory
     */
    public static HsqlSocketFactory getInstance(boolean tls) throws Exception {
        return tls ? getSSLImpl()
                   : getPlainImpl();
    }

// -------------------------- public instance methods --------------------------
    public void configureSocket(Socket socket) {

        // default: do nothing
    }

    
Returns a server socket bound to the specified port.
The socket is configured with the socket options
given to this factory.
Params:
port – the port to which to bind the ServerSocket
Throws:
Exception – if a network error occurs
Returns:
the ServerSocket/**
     * Returns a server socket bound to the specified port.
     * The socket is configured with the socket options
     * given to this factory.
     *
     * @return the ServerSocket
     * @param port the port to which to bind the ServerSocket
     * @throws Exception if a network error occurs
     */
    public ServerSocket createServerSocket(int port) throws Exception {
        return new ServerSocket(port);
    }

    
Returns a server socket bound to the specified port.
The socket is configured with the socket options
given to this factory.
Params:
port – the port to which to bind the ServerSocket
Throws:
Exception – if a network error occurs
Returns:
the ServerSocket/**
     * Returns a server socket bound to the specified port.
     * The socket is configured with the socket options
     * given to this factory.
     *
     * @return the ServerSocket
     * @param port the port to which to bind the ServerSocket
     * @throws Exception if a network error occurs
     */
    public ServerSocket createServerSocket(int port,
                                           String address) throws Exception {
        return new ServerSocket(port, 128, InetAddress.getByName(address));
    }

    
If socket argument is not null, returns it. If it is null,
creates a socket and connects it to the specified remote host at the
specified remote port. This socket is configured using the socket options
established for this factory.
Params:
socket – the existing socket, can be null
host – the server host
port – the server port
Throws:
Exception – if a network error occurs
Returns:
the socket/**
     * If socket argument is not null, returns it. If it is null,
     * creates a socket and connects it to the specified remote host at the
     * specified remote port. This socket is configured using the socket options
     * established for this factory.
     *
     * @return the socket
     * @param socket the existing socket, can be null
     * @param host the server host
     * @param port the server port
     * @throws Exception if a network error occurs
     */
    public Socket createSocket(Socket socket, String host,
                               int port) throws Exception {
        return socket == null ? new Socket(host, port)
                              : socket;
    }

    
Creates a socket and connects it to the specified remote host at the
specified remote port. This socket is configured using the socket options
established for this factory.
Params:
host – the server host
port – the server port
Throws:
Exception – if a network error occurs
Returns:
the socket/**
     * Creates a socket and connects it to the specified remote host at the
     * specified remote port. This socket is configured using the socket options
     * established for this factory.
     *
     * @return the socket
     * @param host the server host
     * @param port the server port
     * @throws Exception if a network error occurs
     */
    public Socket createSocket(String host, int port) throws Exception {
        return new Socket(host, port);
    }

    
Retrieves whether this factory produces secure sockets.
Returns:
true if this factory produces secure sockets/**
     * Retrieves whether this factory produces secure sockets.
     *
     * @return true if this factory produces secure sockets
     */
    public boolean isSecure() {
        return false;
    }

// ------------------------ static utility methods -----------------------------
    private static HsqlSocketFactory getPlainImpl() throws Exception {

        synchronized (HsqlSocketFactory.class) {
            if (plainImpl == null) {
                plainImpl = new HsqlSocketFactory();
            }
        }

        return plainImpl;
    }

    private static HsqlSocketFactory getSSLImpl() throws Exception {

        synchronized (HsqlSocketFactory.class) {
            if (sslImpl == null) {
                sslImpl =
                    newFactory("org.hsqldb.server.HsqlSocketFactorySecure");
            }
        }

        return sslImpl;
    }

    
Retrieves a new HsqlSocketFactory whose class
is determined by the implClass argument. The basic contract here
is that implementations constructed by this method should return
true upon calling isSecure() iff they actually create secure sockets.
There is no way to guarantee this directly here, so it is simply
trusted that an  implementation is secure if it returns true
for calls to isSecure();
Params:
implClass – the fully qualified name of the desired
     class to construct
Throws:
Exception – if a new secure socket factory cannot
     be constructed
Returns:
a new secure socket factory/**
     * Retrieves a new HsqlSocketFactory whose class
     * is determined by the implClass argument. The basic contract here
     * is that implementations constructed by this method should return
     * true upon calling isSecure() iff they actually create secure sockets.
     * There is no way to guarantee this directly here, so it is simply
     * trusted that an  implementation is secure if it returns true
     * for calls to isSecure();
     *
     * @return a new secure socket factory
     * @param implClass the fully qualified name of the desired
     *      class to construct
     * @throws Exception if a new secure socket factory cannot
     *      be constructed
     */
    private static HsqlSocketFactory newFactory(String implClass)
    throws Exception {

        Class       clazz;
        Constructor ctor;
        Class[]     ctorParm;
        Object[]    ctorArg;
        Object      factory;

        clazz    = Class.forName(implClass);
        ctorParm = new Class[0];

        // protected constructor
        ctor    = clazz.getDeclaredConstructor(ctorParm);
        ctorArg = new Object[0];

        try {
            factory = ctor.newInstance(ctorArg);
        } catch (InvocationTargetException e) {
            Throwable t = e.getTargetException();

            throw (t instanceof Exception) ? ((Exception) t)
                                           : new RuntimeException(
                                               t.toString());
        }

        return (HsqlSocketFactory) factory;
    }

// --
}