/*
 * Copyright (c) 1994, 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.
 */

FTP stream opener.
/**
 * FTP stream opener.
 */

package sun.net.www.protocol.ftp;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.BufferedInputStream;
import java.io.FilterInputStream;
import java.io.FilterOutputStream;
import java.io.FileNotFoundException;
import java.net.URL;
import java.net.URLStreamHandler;
import java.net.SocketPermission;
import java.net.UnknownHostException;
import java.net.MalformedURLException;
import java.net.InetSocketAddress;
import java.net.URI;
import java.net.Proxy;
import java.net.ProxySelector;
import java.util.StringTokenizer;
import java.util.Iterator;
import java.security.Permission;
import sun.net.www.MessageHeader;
import sun.net.www.MeteredStream;
import sun.net.www.URLConnection;
import sun.net.www.protocol.http.HttpURLConnection;
import sun.net.ftp.FtpClient;
import sun.net.ftp.FtpProtocolException;
import sun.net.ProgressSource;
import sun.net.ProgressMonitor;
import sun.net.www.ParseUtil;
import sun.security.action.GetPropertyAction;


This class Opens an FTP input (or output) stream given a URL.
It works as a one shot FTP transfer :

Login
Get (or Put) the file
Disconnect

You should not have to use it directly in most cases because all will be handled
in a abstract layer. Here is an example of how to use the class :

URL url = new URL("ftp://ftp.sun.com/pub/test.txt");

UrlConnection con = url.openConnection();

InputStream is = con.getInputStream();

...

is.close();
See Also:
FtpClient/**
 * This class Opens an FTP input (or output) stream given a URL.
 * It works as a one shot FTP transfer :
 * <UL>
 * <LI>Login</LI>
 * <LI>Get (or Put) the file</LI>
 * <LI>Disconnect</LI>
 * </UL>
 * You should not have to use it directly in most cases because all will be handled
 * in a abstract layer. Here is an example of how to use the class :
 * <P>
 * <code>URL url = new URL("ftp://ftp.sun.com/pub/test.txt");<p>
 * UrlConnection con = url.openConnection();<p>
 * InputStream is = con.getInputStream();<p>
 * ...<p>
 * is.close();</code>
 *
 * @see sun.net.ftp.FtpClient
 */
public class FtpURLConnection extends URLConnection {

    // In case we have to use proxies, we use HttpURLConnection
    HttpURLConnection http = null;
    private Proxy instProxy;
    Proxy proxy = null;

    InputStream is = null;
    OutputStream os = null;

    FtpClient ftp = null;
    Permission permission;

    String password;
    String user;

    String host;
    String pathname;
    String filename;
    String fullpath;
    int port;
    static final int NONE = 0;
    static final int ASCII = 1;
    static final int BIN = 2;
    static final int DIR = 3;
    int type = NONE;
    /* Redefine timeouts from java.net.URLConnection as we nee -1 to mean
     * not set. This is to ensure backward compatibility.
     */
    private int connectTimeout = -1;
    private int readTimeout = -1;

    
For FTP URLs we need to have a special InputStream because we
need to close 2 sockets after we're done with it :
 - The Data socket (for the file).
  - The command socket (FtpClient).
Since that's the only class that needs to see that, it is an inner class.
/**
     * For FTP URLs we need to have a special InputStream because we
     * need to close 2 sockets after we're done with it :
     *  - The Data socket (for the file).
     *   - The command socket (FtpClient).
     * Since that's the only class that needs to see that, it is an inner class.
     */
    protected class FtpInputStream extends FilterInputStream {
        FtpClient ftp;
        FtpInputStream(FtpClient cl, InputStream fd) {
            super(new BufferedInputStream(fd));
            ftp = cl;
        }

        public void close() throws IOException {
            super.close();
            try {
                if (ftp != null)
                    ftp.closeServer();
            } catch (IOException ex) {
            }
        }
    }

    
For FTP URLs we need to have a special OutputStream because we
need to close 2 sockets after we're done with it :
 - The Data socket (for the file).
  - The command socket (FtpClient).
Since that's the only class that needs to see that, it is an inner class.
/**
     * For FTP URLs we need to have a special OutputStream because we
     * need to close 2 sockets after we're done with it :
     *  - The Data socket (for the file).
     *   - The command socket (FtpClient).
     * Since that's the only class that needs to see that, it is an inner class.
     */
    protected class FtpOutputStream extends FilterOutputStream {
        FtpClient ftp;
        FtpOutputStream(FtpClient cl, OutputStream fd) {
            super(fd);
            ftp = cl;
        }

        public void close() throws IOException {
            super.close();
            try {
                if (ftp != null)
                    ftp.closeServer();
            } catch (IOException ex) {
            }
        }
    }

    
Creates an FtpURLConnection from a URL.
Params:
url –     The URL to retrieve or store./**
     * Creates an FtpURLConnection from a URL.
     *
     * @param   url     The <code>URL</code> to retrieve or store.
     */
    public FtpURLConnection(URL url) {
        this(url, null);
    }

    
Same as FtpURLconnection(URL) with a per connection proxy specified
/**
     * Same as FtpURLconnection(URL) with a per connection proxy specified
     */
    FtpURLConnection(URL url, Proxy p) {
        super(url);
        instProxy = p;
        host = url.getHost();
        port = url.getPort();
        String userInfo = url.getUserInfo();

        if (userInfo != null) { // get the user and password
            int delimiter = userInfo.indexOf(':');
            if (delimiter == -1) {
                user = ParseUtil.decode(userInfo);
                password = null;
            } else {
                user = ParseUtil.decode(userInfo.substring(0, delimiter++));
                password = ParseUtil.decode(userInfo.substring(delimiter));
            }
        }
    }

    private void setTimeouts() {
        if (ftp != null) {
            if (connectTimeout >= 0)
                ftp.setConnectTimeout(connectTimeout);
            if (readTimeout >= 0)
                ftp.setReadTimeout(readTimeout);
        }
    }

    
Connects to the FTP server and logs in.
Throws:
FtpLoginException – if the login is unsuccessful
FtpProtocolException – if an error occurs
UnknownHostException – if trying to connect to an unknown host/**
     * Connects to the FTP server and logs in.
     *
     * @throws  FtpLoginException if the login is unsuccessful
     * @throws  FtpProtocolException if an error occurs
     * @throws  UnknownHostException if trying to connect to an unknown host
     */

    public synchronized void connect() throws IOException {
        if (connected) {
            return;
        }

        Proxy p = null;
        if (instProxy == null) { // no per connection proxy specified
            /**
             * Do we have to use a proxy?
             */
            ProxySelector sel = java.security.AccessController.doPrivileged(
                new java.security.PrivilegedAction<ProxySelector>() {
                    public ProxySelector run() {
                                return ProxySelector.getDefault();
                            }
                            });
            if (sel != null) {
                URI uri = sun.net.www.ParseUtil.toURI(url);
                Iterator<Proxy> it = sel.select(uri).iterator();
                while (it.hasNext()) {
                    p = it.next();
                    if (p == null || p == Proxy.NO_PROXY ||
                        p.type() == Proxy.Type.SOCKS)
                        break;
                    if (p.type() != Proxy.Type.HTTP ||
                        !(p.address() instanceof InetSocketAddress)) {
                        sel.connectFailed(uri, p.address(), new IOException("Wrong proxy type"));
                        continue;
                    }
                    // OK, we have an http proxy
                    InetSocketAddress paddr = (InetSocketAddress) p.address();
                    try {
                        http = new HttpURLConnection(url, p);
                        if (connectTimeout >= 0)
                            http.setConnectTimeout(connectTimeout);
                        if (readTimeout >= 0)
                            http.setReadTimeout(readTimeout);
                        http.connect();
                        connected = true;
                        return;
                    } catch (IOException ioe) {
                        sel.connectFailed(uri, paddr, ioe);
                        http = null;
                    }
                }
            }
        } else { // per connection proxy specified
            p = instProxy;
            if (p.type() == Proxy.Type.HTTP) {
                http = new HttpURLConnection(url, instProxy);
                if (connectTimeout >= 0)
                    http.setConnectTimeout(connectTimeout);
                if (readTimeout >= 0)
                    http.setReadTimeout(readTimeout);
                http.connect();
                connected = true;
                return;
            }
        }

        if (user == null) {
            user = "anonymous";
            String vers = java.security.AccessController.doPrivileged(
                new GetPropertyAction("java.version"));
            password = java.security.AccessController.doPrivileged(
                new GetPropertyAction("ftp.protocol.user",
                                      "Java" + vers +"@"));
        }
        try {
            if (p != null)
                ftp = new FtpClient(p);
            else
                ftp = new FtpClient();
            setTimeouts();
            if (port != -1)
                ftp.openServer(host, port);
            else
                ftp.openServer(host);
        } catch (UnknownHostException e) {
            // Maybe do something smart here, like use a proxy like iftp.
            // Just keep throwing for now.
            throw e;
        }
        try {
            ftp.login(user, password);
        } catch (sun.net.ftp.FtpLoginException e) {
            ftp.closeServer();
            throw e;
        }
        connected = true;
    }


    /*
     * Decodes the path as per the RFC-1738 specifications.
     */
    private void decodePath(String path) {
        int i = path.indexOf(";type=");
        if (i >= 0) {
            String s1 = path.substring(i+6, path.length());
            if ("i".equalsIgnoreCase(s1))
                type = BIN;
            if ("a".equalsIgnoreCase(s1))
                type = ASCII;
            if ("d".equalsIgnoreCase(s1))
                type = DIR;
            path = path.substring(0, i);
        }
        if (path != null && path.length() > 1 &&
            path.charAt(0) == '/')
            path = path.substring(1);
        if (path == null || path.length() == 0)
            path = "./";
        if (!path.endsWith("/")) {
            i = path.lastIndexOf('/');
            if (i > 0) {
                filename = path.substring(i+1, path.length());
                filename = ParseUtil.decode(filename);
                pathname = path.substring(0, i);
            } else {
                filename = ParseUtil.decode(path);
                pathname = null;
            }
        } else {
            pathname = path.substring(0, path.length() - 1);
            filename = null;
        }
        if (pathname != null)
            fullpath = pathname + "/" + (filename != null ? filename : "");
        else
            fullpath = filename;
    }

    /*
     * As part of RFC-1738 it is specified that the path should be
     * interpreted as a series of FTP CWD commands.
     * This is because, '/' is not necessarly the directory delimiter
     * on every systems.
     */

    private void cd(String path) throws IOException {
        if (path == null || "".equals(path))
            return;
        if (path.indexOf('/') == -1) {
            ftp.cd(ParseUtil.decode(path));
            return;
        }

        StringTokenizer token = new StringTokenizer(path,"/");
        while (token.hasMoreTokens())
            ftp.cd(ParseUtil.decode(token.nextToken()));
    }

    
Get the InputStream to retreive the remote file. It will issue the
"get" (or "dir") command to the ftp server.
Throws:
IOException – if already opened for output
FtpProtocolException – if errors occur during the transfert.
Returns:
 the InputStream to the connection./**
     * Get the InputStream to retreive the remote file. It will issue the
     * "get" (or "dir") command to the ftp server.
     *
     * @return  the <code>InputStream</code> to the connection.
     *
     * @throws  IOException if already opened for output
     * @throws  FtpProtocolException if errors occur during the transfert.
     */
    public InputStream getInputStream() throws IOException {
        if (!connected) {
            connect();
        }

        if (http != null)
            return http.getInputStream();

        if (os != null)
            throw new IOException("Already opened for output");

        if (is != null) {
            return is;
        }

        MessageHeader msgh = new MessageHeader();

        try {
            decodePath(url.getPath());
            if (filename == null || type == DIR) {
                ftp.ascii();
                cd(pathname);
                if (filename == null)
                    is = new FtpInputStream(ftp, ftp.list());
                else
                    is = new FtpInputStream(ftp, ftp.nameList(filename));
            } else {
                if (type == ASCII)
                    ftp.ascii();
                else
                    ftp.binary();
                cd(pathname);
                is = new FtpInputStream(ftp, ftp.get(filename));
            }

            /* Try to get the size of the file in bytes.  If that is
               successful, then create a MeteredStream. */
            try {
                String response = ftp.getResponseString();
                int offset;

                if ((offset = response.indexOf(" bytes)")) != -1) {
                    int i = offset;
                    int c;

                    while (--i >= 0 && ((c = response.charAt(i)) >= '0'
                                        && c <= '9'))
                        ;
                    i = Integer.parseInt(response.substring(i + 1, offset));
                    msgh.add("content-length", ""+i);
                    if (i > 0) {

                        // Wrap input stream with MeteredStream to ensure read() will always return -1
                        // at expected length.

                        // Check if URL should be metered
                        boolean meteredInput = ProgressMonitor.getDefault().shouldMeterInput(url, "GET");
                        ProgressSource pi = null;

                        if (meteredInput)   {
                            pi = new ProgressSource(url, "GET", i);
                            pi.beginTracking();
                        }

                        is = new MeteredStream(is, pi, i);
                    }
                }
            } catch (Exception e) {
                e.printStackTrace();
                /* do nothing, since all we were doing was trying to
                   get the size in bytes of the file */
            }

            String type = guessContentTypeFromName(fullpath);
            if (type == null && is.markSupported()) {
                type = guessContentTypeFromStream(is);
            }
            if (type != null) {
                msgh.add("content-type", type);
            }
        } catch (FileNotFoundException e) {
            try {
                cd(fullpath);
                /* if that worked, then make a directory listing
                   and build an html stream with all the files in
                   the directory */
                ftp.ascii();

                is = new FtpInputStream(ftp, ftp.list());
                msgh.add("content-type", "text/plain");
            } catch (IOException ex) {
                throw new FileNotFoundException(fullpath);
            }
        }
        setProperties(msgh);
        return is;
    }

    
Get the OutputStream to store the remote file. It will issue the
"put" command to the ftp server.
Throws:
IOException – if already opened for input or the URL
         points to a directory
FtpProtocolException – if errors occur during the transfert.
Returns:
 the OutputStream to the connection./**
     * Get the OutputStream to store the remote file. It will issue the
     * "put" command to the ftp server.
     *
     * @return  the <code>OutputStream</code> to the connection.
     *
     * @throws  IOException if already opened for input or the URL
     *          points to a directory
     * @throws  FtpProtocolException if errors occur during the transfert.
     */
    public OutputStream getOutputStream() throws IOException {
        if (!connected) {
            connect();
        }

        if (http != null)
            return http.getOutputStream();

        if (is != null)
            throw new IOException("Already opened for input");

        if (os != null) {
            return os;
        }

        decodePath(url.getPath());
        if (filename == null || filename.length() == 0)
            throw new IOException("illegal filename for a PUT");
        if (pathname != null)
            cd(pathname);
        if (type == ASCII)
            ftp.ascii();
        else
            ftp.binary();
        os = new FtpOutputStream(ftp, ftp.put(filename));
        return os;
    }

    String guessContentTypeFromFilename(String fname) {
        return guessContentTypeFromName(fname);
    }

    
Gets the Permission associated with the host & port.
Returns:
 The Permission object./**
     * Gets the <code>Permission</code> associated with the host & port.
     *
     * @return  The <code>Permission</code> object.
     */
    public Permission getPermission() {
        if (permission == null) {
            int port = url.getPort();
            port = port < 0 ? FtpClient.FTP_PORT : port;
            String host = this.host + ":" + port;
            permission = new SocketPermission(host, "connect");
        }
        return permission;
    }

    
Sets the general request property. If a property with the key already
exists, overwrite its value with the new value.
Params:
key –     the keyword by which the request is known
                 (e.g., "accept").
value –   the value associated with it.
Throws:
IllegalStateException – if already connected
See Also:
getRequestProperty(String)/**
     * Sets the general request property. If a property with the key already
     * exists, overwrite its value with the new value.
     *
     * @param   key     the keyword by which the request is known
     *                  (e.g., "<code>accept</code>").
     * @param   value   the value associated with it.
     * @throws IllegalStateException if already connected
     * @see #getRequestProperty(java.lang.String)
     */
    public void setRequestProperty(String key, String value) {
        super.setRequestProperty (key, value);
        if ("type".equals (key)) {
            if ("i".equalsIgnoreCase(value))
                type = BIN;
            else if ("a".equalsIgnoreCase(value))
                type = ASCII;
            else
                if ("d".equalsIgnoreCase(value))
                    type = DIR;
            else
                throw new IllegalArgumentException(
                    "Value of '" + key +
                    "' request property was '" + value +
                    "' when it must be either 'i', 'a' or 'd'");
        }
    }

    
Returns the value of the named general request property for this
connection.
Params:
key – the keyword by which the request is known (e.g., "accept").
Throws:
IllegalStateException – if already connected
See Also:
setRequestProperty(String, String)
Returns:
 the value of the named general request property for this
          connection./**
     * Returns the value of the named general request property for this
     * connection.
     *
     * @param key the keyword by which the request is known (e.g., "accept").
     * @return  the value of the named general request property for this
     *           connection.
     * @throws IllegalStateException if already connected
     * @see #setRequestProperty(java.lang.String, java.lang.String)
     */
    public String getRequestProperty(String key) {
        String value = super.getRequestProperty (key);

        if (value == null) {
            if ("type".equals (key))
                value = (type == ASCII ? "a" : type == DIR ? "d" : "i");
        }

        return value;
    }

    public void setConnectTimeout(int timeout) {
        if (timeout < 0)
            throw new IllegalArgumentException("timeouts can't be negative");
        connectTimeout = timeout;
    }

    public int getConnectTimeout() {
        return (connectTimeout < 0 ? 0 : connectTimeout);
    }

    public void setReadTimeout(int timeout) {
        if (timeout < 0)
            throw new IllegalArgumentException("timeouts can't be negative");
        readTimeout = timeout;
    }

    public int getReadTimeout() {
        return readTimeout < 0 ? 0 : readTimeout;
    }
}