org.dlese.dpc.schemedit.url
Class UrlHelper

java.lang.Object
  org.dlese.dpc.schemedit.url.UrlHelper

public class UrlHelper
extends Object

Utilities for manipulating and comparing URLs

Version:

$Id: UrlHelper.java,v 1.3 2009/03/20 23:33:58 jweather Exp $

Author:

ostwald

Constructor Summary

UrlHelper()
Constructor for the UrlHelper object

Method Summary

static int	deltaPath(URL url1, URL url2) Compute a "delta" between two URLs that serves as a measure of their similarity.
static int	deltaPathLen(String urlStr1, String urlStr2) Returns the difference in path lengths of two urls represented as strings
static int	deltaPathLen(URL url1, URL url2) Find the difference between the path lengths of two urls.
static URL	getAncestor(String urlStr, int levels) Gets the specified ancestor (using the levels param) of a given url (represented as a string).
static URL	getAncestor(URL url, int levels) Gets the ancestor of the given URL by calling getParent "level" times.
static String	getParamValue(String paramName, String url) Gets the paramValue attribute of the UrlHelper class
static URL	getParent(String urlStr) Gets the parent attribute of the UrlHelper class
static URL	getParent(URL url) Gets the parent attribute of the UrlHelper class
static String	getPathItem(String urlStr, int index) Gets the pathItem attribute of the UrlHelper class
static String	getPathItem(URL url, int index) return the nth path item, empty string if nth item does not exist
static List	getPathItems(URL url) Returns the segments of a url path split around the path separator ("/")
static int	getPathLen(String s) Returns the length of the path component of a url represented as a string
static int	getPathLen(URL url) Returns the length of the path component (URL.getPath()) of a url.
static Map	getQueryArgs(String url) Gets the queryArgs attribute of the UrlHelper class
static String	getSimilarUrlPath(String urlStr, int levels) Use wild cards to make a url that will retrieve all "ancestors" of the given url up to the specified level.
static URL	getUrl(String urlStr) Converts a string into a URL instance, returning null in the case of a malformedUrl
static boolean	isSimilar(String baseStr, String urlStr, int maxDelta) Checks whether two urls are similar within a variable "distance" that is a function of the respective lengths of the two urls.
static boolean	isValid(URL url) A valid URL must have values for protocol and host.
static void	main(String[] args) The main program for the UrlHelper class
static String	normalize(String s) To be called on form input from metadata editor
static boolean	validateUrl(String urlStr) Ensure that a urlStr contains a valid protocol and a host.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

UrlHelper

public UrlHelper()

Constructor for the UrlHelper object

Method Detail

normalize

public static String normalize(String s)

To be called on form input from metadata editor

Parameters:

s - NOT YET DOCUMENTED

Returns:

NOT YET DOCUMENTED

Throws:

URISyntaxException - NOT YET DOCUMENTED

isSimilar

public static boolean isSimilar(String baseStr,
                                String urlStr,
                                int maxDelta)

Checks whether two urls are similar within a variable "distance" that is a function of the respective lengths of the two urls.

assumes urlStr represents a valid URL, and that the protocol, host, and port match those of the baseURL. NOTE: the urls we want to check in DCS will already pass this test because they are retrieved by a query string that is built from a legal baseURL and include equal protocol, host and ports.

Parameters:

baseStr - A reference URL against which to check another url

urlStr - A url string to be checked for similarity against baseUrl

maxDelta - The maximum difference in url length (the length of the value returned by URL.getPath() split by "/")

Returns:

true if the urlStr is similar to baseUrl, false if the urls are not similar, or if either cannot be converted into a URL instance.

deltaPathLen

public static int deltaPathLen(URL url1,
                               URL url2)

Find the difference between the path lengths of two urls.

Parameters:

url1 - Description of the Parameter

url2 - Description of the Parameter

Returns:

Description of the Return Value

deltaPath

public static int deltaPath(URL url1,
                            URL url2)

Compute a "delta" between two URLs that serves as a measure of their similarity.

First find the portions of the two paths that are identical. Then sum the items in each url path items that are not found in the other.

Parameters:

url1 - Description of the Parameter

url2 - Description of the Parameter

Returns:

Description of the Return Value

deltaPathLen

public static int deltaPathLen(String urlStr1,
                               String urlStr2)

Returns the difference in path lengths of two urls represented as strings

Parameters:

urlStr1 - Description of the Parameter

urlStr2 - Description of the Parameter

Returns:

Description of the Return Value

getPathItem

public static String getPathItem(URL url,
                                 int index)

return the nth path item, empty string if nth item does not exist

Parameters:

url - Description of the Parameter

index - Description of the Parameter

Returns:

The pathItem value

getPathItem

public static String getPathItem(String urlStr,
                                 int index)

Gets the pathItem attribute of the UrlHelper class

Parameters:

urlStr - Description of the Parameter

index - Description of the Parameter

Returns:

The pathItem value

getPathItems

public static List getPathItems(URL url)

Returns the segments of a url path split around the path separator ("/")

Parameters:

url - A URL instance

Returns:

The pathItems as a List

getPathLen

public static int getPathLen(URL url)

Returns the length of the path component (URL.getPath()) of a url.

Parameters:

url - Description of the Parameter

Returns:

The pathLen value

getPathLen

public static int getPathLen(String s)

Returns the length of the path component of a url represented as a string

Parameters:

s - Description of the Parameter

Returns:

The path length, or 0 if the provided string could not be converted into a URL instance.

getUrl

public static URL getUrl(String urlStr)

Converts a string into a URL instance, returning null in the case of a malformedUrl

Parameters:

urlStr - Description of the Parameter

Returns:

A URL instance or null if the urlStr is malformed.

isValid

public static boolean isValid(URL url)

A valid URL must have values for protocol and host.

Parameters:

url - A URL instance

Returns:

true if the URL has both a protocal and host

See Also:

URL

validateUrl

public static boolean validateUrl(String urlStr)
                           throws MalformedURLException

Ensure that a urlStr contains a valid protocol and a host. Similar to isValid, but returns an exception containing an error msg that can be passed back to user.

Parameters:

urlStr - String representation of a URL

Returns:

true if valid

Throws:

MalformedURLException - if not valid

getSimilarUrlPath

public static String getSimilarUrlPath(String urlStr,
                                       int levels)

Use wild cards to make a url that will retrieve all "ancestors" of the given url up to the specified level.

Parameters:

urlStr - base url to be "generalized" using wildcard

levels - the number of levels up to generalize urlStr

Returns:

The similarUrlPath value

getAncestor

public static URL getAncestor(String urlStr,
                              int levels)

Gets the specified ancestor (using the levels param) of a given url (represented as a string).

Parameters:

urlStr - url represented as a String

levels - specifies how many levels "up" to go.

Returns:

The ancestor value

getAncestor

public static URL getAncestor(URL url,
                              int levels)

Gets the ancestor of the given URL by calling getParent "level" times.

Parameters:

url - Description of the Parameter

levels - Description of the Parameter

Returns:

The ancestor value

getParent

public static URL getParent(String urlStr)

Gets the parent attribute of the UrlHelper class

Parameters:

urlStr - Description of the Parameter

Returns:

The parent value

getParent

public static URL getParent(URL url)

Gets the parent attribute of the UrlHelper class

Parameters:

url - Description of the Parameter

Returns:

The parent value

getParamValue

public static String getParamValue(String paramName,
                                   String url)

Gets the paramValue attribute of the UrlHelper class

Parameters:

paramName - Description of the Parameter

url - Description of the Parameter

Returns:

The paramValue value

getQueryArgs

public static Map getQueryArgs(String url)

Gets the queryArgs attribute of the UrlHelper class

Parameters:

url - Description of the Parameter

Returns:

The queryArgs value

main

public static void main(String[] args)

The main program for the UrlHelper class

Parameters:

args - The command line arguments