src/java/org/apache/nutch/net/URLNormalizerChecker.java

/*
 * 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.net;

import java.net.MalformedURLException;

import org.apache.hadoop.util.ToolRunner;

import org.apache.nutch.util.AbstractChecker;
import org.apache.nutch.util.NutchConfiguration;

/**
 * Checks one given normalizer or all normalizers.
 */
public class URLNormalizerChecker extends AbstractChecker {

  private String scope = URLNormalizers.SCOPE_DEFAULT;
  URLNormalizers normalizers;

  public int run(String[] args) throws Exception {
    usage = "Usage: URLNormalizerChecker [-Dproperty=value]... [-normalizer <normalizerName>] [-scope <scope>] (-stdin | -listen <port> [-keepClientCnxOpen])\n"
        + "\n  -normalizer\tURL normalizer plugin (eg. urlnormalizer-basic) to check,"
        + "\n             \t(if not given all configured URL normalizers are applied)"
        + "\n  -scope     \tone of: default,partition,generate_host_count,fetcher,crawldb,linkdb,inject,outlink"
        + "\n  -stdin     \ttool reads a list of URLs from stdin, one URL per line"
        + "\n  -listen <port>\trun tool as Telnet server listening on <port>"
        + "\n\nAn empty line is added to the output if a URL fails to normalize (MalformedURLException or null returned).\n";

    // Print help when no args given
    if (args.length < 1) {
      System.err.println(usage);
      System.exit(-1);
    }

    int numConsumed;
    for (int i = 0; i < args.length; i++) {
      if (args[i].equals("-normalizer")) {
        getConf().set("plugin.includes", args[++i]);
      } else if (args[i].equals("-scope")) {
        scope = args[++i];
      } else if ((numConsumed = super.parseArgs(args, i)) > 0) {
        i += numConsumed - 1;
      } else {
        System.err.println("ERROR: Not a recognized argument: " + args[i]);
        System.err.println(usage);
        System.exit(-1);
      }
    }

    // Print active normalizer list
    normalizers = new URLNormalizers(getConf(), scope);
    System.out.print("Checking combination of these URLNormalizers: ");
    for (URLNormalizer normalizer : normalizers.getURLNormalizers(scope)) {
      System.out.print(normalizer.getClass().getSimpleName() + " ");
    }
    System.out.println("");

    // Start listening
    return super.run();
  }

  protected int process(String line, StringBuilder output) throws Exception {
    try {
      String norm = normalizers.normalize(line, scope);
      if (norm == null) {
        output.append("");
      } else {
        output.append(norm);
      }
    } catch (MalformedURLException e) {
      output.append("");
    }
    return 0;
  }

  public static void main(String[] args) throws Exception {
    final int res = ToolRunner.run(NutchConfiguration.create(),
        new URLNormalizerChecker(), args);
    System.exit(res);
  }
}