urlutility.java

java版的网络蚂蚁软件

package com.heaton.bot;

import java.io.*;
import java.net.*;

/**
 * This simple static class contains
 * several methods that are useful to
 * manipulate URL's.
 * Copyright 2001-2003 by Jeff Heaton (http://www.jeffheaton.com)
 *
 * @author Jeff Heaton
 * @version 1.2
 */
public class URLUtility {
    
  /**
   * The name that should be used to store any "default documents"
   */
  public static String indexFile = "index.html";

  /**
   * Private constructor prevents insanitation.
   */
  private URLUtility()
  {
  }

  /**
   * Strip the query string from a URL.
   *
   * @param url    The URL to examine.
   * @return The URL with no query string.
   * @exception MalformedURLException
   */
  static public URL stripQuery(URL url)
  throws MalformedURLException
  {
    String file = url.getFile();
    int i=file.indexOf("?");
    if ( i==-1 )
      return url;
    file = file.substring(0,i);
    return new URL(url.getProtocol(),url.getHost(),url.getPort(),file);
  }

  /**
   * Strip the anchor tag from the URL.
   *
   * @param url    The URL to scan.
   * @return The URL with no anchor tag.
   * @exception MalformedURLException
   */
  static public URL stripAnhcor(URL url)
  throws MalformedURLException
  {
    String file = url.getFile();
    return new URL(url.getProtocol(),url.getHost(),url.getPort(),file);
  }

  /**
   * Encodes a string in base64.
   *
   * @param s      The string to encode.
   * @return The encoded string.
   */
  static public String base64Encode(String s)
  {
    ByteArrayOutputStream bout = new ByteArrayOutputStream();

    Base64OutputStream out = new Base64OutputStream(bout);
    try {
      out.write(s.getBytes());
      out.flush();
    } catch ( IOException e ) {
    }

    return bout.toString();
  }

  /**
   * Resolve the base of a URL.
   *
   * @param base   The base.
   * @param rel    The relative path.
   * @return The combined absolute URL.
   */
  static public String resolveBase(String base,String rel)
  {
    String protocol;
    int i = base.indexOf(':');
    if ( i!=-1 ) {
      protocol = base.substring(0,i+1);
      base = "http:" + base.substring(i+1);
    } else
      protocol = null;

    URL url;

    try {
      url = new URL(new URL(base),rel);
    } catch ( MalformedURLException e ) {
      return "";
    }

    if ( protocol!=null ) {
      base = url.toString();
      i = base.indexOf(':');
      if ( i!=-1 )
        base = base.substring(i+1);
      base = protocol + base;
      return base;
    } else
      return url.toString();
  }

  
  public static String convertFilename(String base,String path)
  {
      return convertFilename(base,path,true);
  }


  /**
   * Convert a filename for local storage. Also create the directory
   * tree.
   *
   * @param base   The local path that forms the base of the downloaded web tree.
   * @param path    The URL path.
   * @return The resulting local path to store to.
   */
  public static String convertFilename(String base,String path,boolean mkdir)
  {
    String result = base;
    int index1;
    int index2;

    // add ending slash if needed
    if( result.charAt(result.length()-1)!=File.separatorChar )
      result = result+File.separator;

    // strip the query if needed

    int queryIndex = path.indexOf("?");
    if( queryIndex!=-1 )
    path = path.substring(0,queryIndex);

    // see if an ending / is missing from a directory only

    int lastSlash = path.lastIndexOf(File.separatorChar);
    int lastDot = path.lastIndexOf('.');

    if( path.charAt(path.length()-1)!='/' )
    {
      if(lastSlash>lastDot)
        path+="/"+indexFile;
    }

    // determine actual filename
    lastSlash = path.lastIndexOf('/');

    String filename = "";
    if(lastSlash!=-1)
    {
      filename=path.substring(1+lastSlash);
      path = path.substring(0,1+lastSlash);


      if(filename.equals("") )
        filename=indexFile;
    }
    // create the directory structure, if needed

    index1 = 1;
    do
    {
      index2 = path.indexOf('/',index1);

      if(index2!=-1)
      {
        String dirpart = path.substring(index1,index2);
        result+=dirpart;
        result+=File.separator;

        if(mkdir)
        {
            File f = new File(result);
            f.mkdir();
        }

        index1 = index2+1; 
                                
      }
    } while(index2!=-1);

  // attach name
  result+=filename;

  return result;
  }  
}