Class BinaryLinkExtractor 

java.lang.Object
   |
   +----BinaryLinkExtractor
public class BinaryLinkExtractor
extends Object

NetRand Project

Software Engineering - CS536

University of Wisconsin - Milwaukee

Authors:


File: BinaryLinkExtractor.java

BinaryLinkExtractor extracts links to binary files from HTML files.

Variable Index

o cacheFile
the cache file
o tmp_dir
the name of the directory to store the cache file
o url
the url of the HTML to parse
o urlConn
handles the URL connection

Constructor Index

o BinaryLinkExtractor()
constructor for the BinaryLinkExtractor

Method Index

o cacheHTMLDocument(String)
gets the HTMl file from the remote serve and writes it to a local cache file
o deleteCacheDocument()
deletes the cache file
o extract(String, String)
extracts the text within quotes from a line immediately after a given key
o extractBinaryLinks(String)
calls the appropriate functions to extract the binary file links from given URL.
o isBaseTag(String)
o isBinaryFile(String)
o isHypertextLink(String)
o isImageSourceTag(String)
o readTag(FileInputStream)
parses for a HTML tag in a HTML file

Variables

o url 
 private URL url
the url of the HTML to parse

o urlConn 
 private URLConnection urlConn
handles the URL connection

o tmp_dir 
 private String tmp_dir
the name of the directory to store the cache file

o cacheFile 
 private File cacheFile
the cache file

Constructors

o BinaryLinkExtractor 
 public BinaryLinkExtractor()
constructor for the BinaryLinkExtractor

Methods

o extractBinaryLinks 
 public LinkedList extractBinaryLinks(String urlString)
calls the appropriate functions to extract the binary file links from given URL.

Parameters:
urlString - - the target URL
Returns:
a LinkedList containing the URLs to the found binary files
o cacheHTMLDocument 
 private String cacheHTMLDocument(String urlString) throws IOException
gets the HTMl file from the remote serve and writes it to a local cache file

Parameters:
urlString - - the URL of the target HTML file
Throws: IOException
if there was an error reading the HTML file
o deleteCacheDocument 
 private void deleteCacheDocument()
deletes the cache file

o readTag 
 private String readTag(FileInputStream theHTML)
parses for a HTML tag in a HTML file

Parameters:
theHTML - - the HTML file's input stream
Returns:
a String containing the HTML tag, or null if no tag was found
o extract 
 private String extract(String line,
                        String key)
extracts the text within quotes from a line immediately after a given key

Parameters:
line - - the line to extract the test from
key - - the key to search for
Returns:
a String containing the extracted text
o isBaseTag 
 private boolean isBaseTag(String tag)
Parameters:
tag - - the HTML tag to test
Returns:
true iff the tag represents the HTML BASE tag, otherwise false
o isHypertextLink 
 private boolean isHypertextLink(String tag)
Parameters:
tag - - the HTML tag to test
Returns:
true iff the HTML tag contains a hypertext link, otherwise false
o isImageSourceTag 
 private boolean isImageSourceTag(String tag)
Parameters:
tag - - the HTML tag to test
Returns:
true iff the HTML tag is an IMG SRC tag, otherwise false
o isBinaryFile 
 private boolean isBinaryFile(String link)
Parameters:
link - - the hypertext link to test
Returns:
true iff the link references a binary file, otherwise false