/**
* 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.file;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.nutch.crawl.CrawlDatum;
import org.apache.hadoop.io.Text;
import org.apache.nutch.metadata.Metadata;
import org.apache.nutch.net.protocols.HttpDateFormat;
import org.apache.nutch.net.protocols.Response;
import org.apache.hadoop.conf.Configuration;
import org.apache.nutch.protocol.Content;
import org.apache.nutch.protocol.EmptyRobotRules;
import org.apache.nutch.protocol.Protocol;
import org.apache.nutch.protocol.ProtocolOutput;
import org.apache.nutch.protocol.ProtocolStatus;
import org.apache.nutch.protocol.RobotRules;
import org.apache.nutch.util.NutchConfiguration;
import java.net.URL;
/************************************
* File.java deals with file: scheme.
*
* Configurable parameters are defined under "FILE properties" section
* in ./conf/nutch-default.xml or similar.
*
* @author John Xing
***********************************/
public class File implements Protocol {
public static final Log LOG = LogFactory.getLog(File.class);
static final int MAX_REDIRECTS = 5;
int maxContentLength;
// 20040412, xing
// the following three: HttpDateFormat, MimetypesFileTypeMap, MagicFile
// are placed in each thread before we check out if they're thread-safe.
// http date format
HttpDateFormat httpDateFormat = null;
private Configuration conf;
// constructor
public File() {
this.httpDateFormat = new HttpDateFormat();
}
/** Set the point at which content is truncated. */
public void setMaxContentLength(int length) {maxContentLength = length;}
public ProtocolOutput getProtocolOutput(Text url, CrawlDatum datum) {
String urlString = url.toString();
try {
URL u = new URL(urlString);
int redirects = 0;
while (true) {
FileResponse response;
response = new FileResponse(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 FileException("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 FileError(code);
}
}
} catch (Exception e) {
e.printStackTrace();
return new ProtocolOutput(null, new ProtocolStatus(e));
}
}
// protected void finalize () {
// // nothing here
// }
/** For debugging. */
public static void main(String[] args) throws Exception {
int maxContentLength = Integer.MIN_VALUE;
String logLevel = "info";
boolean dumpContent = false;
String urlString = null;
String usage = "Usage: File [-logLevel level] [-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("-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];
}
File file = new File();
file.setConf(NutchConfiguration.create());
if (maxContentLength != Integer.MIN_VALUE) // set maxContentLength
file.setMaxContentLength(maxContentLength);
// set log level
//LOG.setLevel(Level.parse((new String(logLevel)).toUpperCase()));
Content content = file.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()));
}
file = null;
}
public void setConf(Configuration conf) {
this.conf = conf;
this.maxContentLength = conf.getInt("file.content.limit", 64 * 1024);
}
public Configuration getConf() {
return this.conf;
}
public RobotRules getRobotRules(Text url, CrawlDatum datum) {
return EmptyRobotRules.RULES;
}
}