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1 /* ClientFTP.java
2  *
3  * $Id: ClientFTP.java,v 1.2 2006/08/31 22:31:23 paul_jack Exp $
4  *
5  * Created on Jun 5, 2003
6  *
7  * Copyright (C) 2003 Internet Archive.
8  *
9  * This file is part of the Heritrix web crawler (crawler.archive.org).
10  *
11  * Heritrix is free software; you can redistribute it and/or modify
12  * it under the terms of the GNU Lesser Public License as published by
13  * the Free Software Foundation; either version 2.1 of the License, or
14  * any later version.
15  *
16  * Heritrix is distributed in the hope that it will be useful,
17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19  * GNU Lesser Public License for more details.
20  *
21  * You should have received a copy of the GNU Lesser Public License
22  * along with Heritrix; if not, write to the Free Software
23  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
24  */
25 package org.archive.net;
26
27
28 import java.io.IOException JavaDoc;
29 import java.net.Socket JavaDoc;
30
31 import org.apache.commons.net.ftp.FTPClient;
32 import org.apache.commons.net.ftp.FTPReply;
33
34
35 /**
36  * Client for FTP operations. This class is necessary only because the
37  * {@link #_openDataConnection_(int, String)} method is protected in
38  * the superclass, and we need to call it directly to handle directory
39  * listings. (The code that provides directory listings in the
40  * superclass doesn't scale: It reads the entire directory into
41  * an in-memory list).
42  *
43  * <p>Additionally, "strict" methods are provided for the other operations
44  * we use. Maddeningly, the superclass never raises exceptions. If an
45  * FTP operation fails, then the superclass methods generally return false.
46  * A developer then needs to check the {@link FTP#getReplyCode()}
47  * method to see what actually went wrong. The "strict" methods provided
48  * by this class invoke the superclass method, check if the success flag
49  * is false, and then raise an {@link FTPException} with the value of
50  * {@link FTP#getReplyCode()}.
51  *
52  * @author pjack
53  */
54 public class ClientFTP extends FTPClient {
55     
56     
57     /**
58      * Constructs a new <code>ClientFTP</code>.
59      */
60     public ClientFTP() {
61     }
62     
63
64     /**
65      * Connects to the FTP server at the given host and port.
66      *
67      * @param host the host of the FTP server to connect to
68      * @param port the port the FTP server listens on
69      * @throws IOException if the connection cannot be made due to IO error
70      * @throws FTPException if the server refuses the connection
71      */
72     public void connectStrict(String JavaDoc host, int port) throws IOException JavaDoc {
73         this.connect(host, port);
74         int reply = this.getReplyCode();
75         if (!FTPReply.isPositiveCompletion(reply)) {
76             throw new FTPException(reply);
77         }
78     }
79
80     
81     /**
82      * Login to the FTP server with the given username and password.
83      *
84      * @param user the username to login under
85      * @param pass the password to use
86      * @throws IOException if a network error occurs
87      * @throws FTPException if the login is rejected by the server
88      * @throws org.apache.commons.net.ftp.FTPConnectionClosedException
89      * if the FTP server prematurely closes the connection (for
90      * instance, if the client was idle for too long)
91      */
92     public void loginStrict(String JavaDoc user, String JavaDoc pass) throws IOException JavaDoc {
93         boolean r = this.login(user, pass);
94         if (!r) {
95             throw new FTPException(this.getReplyCode());
96         }
97     }
98
99     
100     /**
101      * Tells the FTP server to send binary files.
102      *
103      * @throws IOException if a network error occurs
104      * @throws FTPException if the server rejects the command
105      * @throws org.apache.commons.net.ftp.FTPConnectionClosedException
106      * if the FTP server prematurely closes the connection (for
107      * instance, if the client was idle for too long)
108      */
109     public void setBinary() throws IOException JavaDoc {
110         boolean r = super.setFileType(BINARY_FILE_TYPE);
111         if (!r) {
112             throw new FTPException(getReplyCode());
113         }
114     }
115
116
117     /**
118      * Opens a data connection.
119      *
120      * @param command the data command (eg, RETR or LIST)
121      * @param path the path of the file to retrieve
122      * @return the socket to read data from
123      * @throws IOException if a network error occurs
124      * @throws FTPException if a protocol error occurs
125      */
126     public Socket JavaDoc openDataConnection(int command, String JavaDoc path)
127     throws IOException JavaDoc {
128         Socket JavaDoc socket = _openDataConnection_(command, path);
129         if (socket == null) {
130             throw new FTPException(this.getReplyCode());
131         }
132         return socket;
133     }
134
135     
136 }
137
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