/**
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.nutch.protocol.ftp;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.apache.commons.net.ftp.FTPFileEntryParser;
import org.apache.nutch.crawl.CrawlDatum;
import org.apache.hadoop.io.Text;
import org.apache.nutch.net.protocols.Response;
import org.apache.hadoop.conf.Configuration;
import org.apache.nutch.protocol.Content;
import org.apache.nutch.protocol.Protocol;
import org.apache.nutch.protocol.ProtocolOutput;
import org.apache.nutch.protocol.ProtocolStatus;
import crawlercommons.robots.BaseRobotRules;
import java.net.URL;
import java.io.IOException;
/**
* This class is a protocol plugin used for ftp: scheme.
* It creates {@link FtpResponse} object and gets the content of the url from it.
* Configurable parameters are {@code ftp.username}, {@code ftp.password},
* {@code ftp.content.limit}, {@code ftp.timeout},
* {@code ftp.server.timeout}, {@code ftp.password},
* {@code ftp.keep.connection} and {@code ftp.follow.talk}.
* For details see "FTP properties" section in {@code nutch-default.xml}.
*/
public class Ftp implements Protocol {
public static final Logger LOG = LoggerFactory.getLogger(Ftp.class);
private static final int BUFFER_SIZE = 16384; // 16*1024 = 16384
static final int MAX_REDIRECTS = 5;
int timeout;
int maxContentLength;
String userName;
String passWord;
// typical/default server timeout is 120*1000 millisec.
// better be conservative here
int serverTimeout;
// when to have client start anew
long renewalTime = -1;
boolean keepConnection;
boolean followTalk;
// ftp client
Client client = null;
// ftp dir list entry parser
FTPFileEntryParser parser = null;
private Configuration conf;
private FtpRobotRulesParser robots = null;
// constructor
public Ftp() {
robots = new FtpRobotRulesParser();
}
/** Set the timeout. */
public void setTimeout(int to) {
timeout = to;
}
/** Set the point at which content is truncated. */
public void setMaxContentLength(int length) {
maxContentLength = length;
}
/** Set followTalk */
public void setFollowTalk(boolean followTalk) {
this.followTalk = followTalk;
}
/** Set keepConnection */
public void setKeepConnection(boolean keepConnection) {
this.keepConnection = keepConnection;
}
/**
* Creates a {@link FtpResponse} object corresponding to the url and
* returns a {@link ProtocolOutput} object as per the content received
*
* @param url Text containing the ftp url
* @param datum The CrawlDatum object corresponding to the url
*
* @return {@link ProtocolOutput} object for the url
*/
public ProtocolOutput getProtocolOutput(Text url, CrawlDatum datum) {
String urlString = url.toString();
try {
URL u = new URL(urlString);
int redirects = 0;
while (true) {
FtpResponse response;
response = new FtpResponse(u, datum, this, getConf()); // make a request
int code = response.getCode();
if (code == 200) { // got a good response
return new ProtocolOutput(response.toContent()); // return it
} else if (code >= 300 && code < 400) { // handle redirect
if (redirects == MAX_REDIRECTS)
throw new FtpException("Too many redirects: " + url);
u = new URL(response.getHeader("Location"));
redirects++;
if (LOG.isTraceEnabled()) {
LOG.trace("redirect to " + u);
}
} else { // convert to exception
throw new FtpError(code);
}
}
} catch (Exception e) {
return new ProtocolOutput(null, new ProtocolStatus(e));
}
}
protected void finalize () {
try {
if (this.client != null && this.client.isConnected()) {
this.client.logout();
this.client.disconnect();
}
} catch (IOException e) {
// do nothing
}
}
/** For debugging. */
public static void main(String[] args) throws Exception {
int timeout = Integer.MIN_VALUE;
int maxContentLength = Integer.MIN_VALUE;
String logLevel = "info";
boolean followTalk = false;
boolean keepConnection = false;
boolean dumpContent = false;
String urlString = null;
String usage = "Usage: Ftp [-logLevel level] [-followTalk] [-keepConnection] [-timeout N] [-maxContentLength L] [-dumpContent] url";
if (args.length == 0) {
System.err.println(usage);
System.exit(-1);
}
for (int i = 0; i < args.length; i++) {
if (args[i].equals("-logLevel")) {
logLevel = args[++i];
} else if (args[i].equals("-followTalk")) {
followTalk = true;
} else if (args[i].equals("-keepConnection")) {
keepConnection = true;
} else if (args[i].equals("-timeout")) {
timeout = Integer.parseInt(args[++i]) * 1000;
} else if (args[i].equals("-maxContentLength")) {
maxContentLength = Integer.parseInt(args[++i]);
} else if (args[i].equals("-dumpContent")) {
dumpContent = true;
} else if (i != args.length-1) {
System.err.println(usage);
System.exit(-1);
} else {
urlString = args[i];
}
}
Ftp ftp = new Ftp();
ftp.setFollowTalk(followTalk);
ftp.setKeepConnection(keepConnection);
if (timeout != Integer.MIN_VALUE) // set timeout
ftp.setTimeout(timeout);
if (maxContentLength != Integer.MIN_VALUE) // set maxContentLength
ftp.setMaxContentLength(maxContentLength);
// set log level
//LOG.setLevel(Level.parse((new String(logLevel)).toUpperCase()));
Content content = ftp.getProtocolOutput(new Text(urlString), new CrawlDatum()).getContent();
System.err.println("Content-Type: " + content.getContentType());
System.err.println("Content-Length: " +
content.getMetadata().get(Response.CONTENT_LENGTH));
System.err.println("Last-Modified: " +
content.getMetadata().get(Response.LAST_MODIFIED));
if (dumpContent) {
System.out.print(new String(content.getContent()));
}
ftp = null;
}
/**
* Set the {@link Configuration} object
*/
public void setConf(Configuration conf) {
this.conf = conf;
this.maxContentLength = conf.getInt("ftp.content.limit", 64 * 1024);
this.timeout = conf.getInt("ftp.timeout", 10000);
this.userName = conf.get("ftp.username", "anonymous");
this.passWord = conf.get("ftp.password", "anonymous@example.com");
this.serverTimeout = conf.getInt("ftp.server.timeout", 60 * 1000);
this.keepConnection = conf.getBoolean("ftp.keep.connection", false);
this.followTalk = conf.getBoolean("ftp.follow.talk", false);
this.robots.setConf(conf);
}
/**
* Get the {@link Configuration} object
*/
public Configuration getConf() {
return this.conf;
}
/**
* Get the robots rules for a given url
*/
public BaseRobotRules getRobotRules(Text url, CrawlDatum datum) {
return robots.getRobotRulesSet(this, url);
}
public int getBufferSize() {
return BUFFER_SIZE;
}
}