de.frame4j.net

Class LocForRel

java.lang.Object

de.frame4j.net.LocForRel

@MinDoc(copyright="Copyright  2001 - 2005 , 2009  A. Weinert",
        author="Albrecht Weinert",
        version="V.33",
        lastModified="27.03.2021",
        usage="use for generating relative links",
        purpose="provide a link relocator using a give base location")
public final class LocForRel
extends Object

Specifies a location for relocation links.

An object of this class contains the location of a file, either absolute or site root related (common root). This common root itself is not relevant and will not be stored in a LocForRel object. An example for a location would be
location = studiesInfo/computerScience.html

The working methods of this class relRef(CharSequence) accept a link denotation like used in href, class, img or else parameters in a HTML page. This denotation must be either absolute or related to a common root, just as is the case for location. In this case the method relRef(CharSequence) makes from that, when ever possible, a link that is relative to location.

If location is given as studiesInfo/computerScience.html (example above) the following would be made

from studiesInfo/it-automation.html

it-automation.html,

from studiesInfo/it-automation.html#kap1

it-automation.html#kap1,

from #kap2

#kap2,

from studiesInfo/computerScience.html#kap2

#kap2,

from studiesInfo/computerScience.html

#TOP remark. 1),

from studiesInfo/it-automation.html

it-automation.html,

from stundenplan/it5.html

../stundenplan/it5.html und

from mailto:lukas@lummerland.lu

mailto:lukas@lummerland.lu

Remark 1): Would the LocForRel object be constructed without default anchor computerScience.html would be returned in this case.

The rationale is to make common site related links instead of absolute ones whenever possible. Using relative links instead of absolute ones allows relocation complete web sites or parts of it from server to server or to local sites by just copying. This even works independently of the protocol.

Objects of this class will be specifically made for a single page (location). The common site root (or the absolute placements) will not be recorded in the object; for all uses, i.e. for all parameters ref (relRef(ref)) that must be (implicitly) the same. Fulfilling this condition is the application's responsibility.

Objects of this class are immutable.


© Copyright 2001 - 2005 Albrecht Weinert

Field Summary

Fields

Modifier and Type	Field and Description
String	ank The page's anchorage part.
boolean	isDir The page's address is a directory.
String	location The page's address.
int	locationDepth Directory depth of location.
boolean	lowerCase All link specifications in lower case.

Method Summary

Modifier and Type	Method and Description
boolean	equals(Object other) Equality with other object.
int	hashCode()
static LocForRel	make(CharSequence address, boolean lowerCase) Make a LocForRel object.
String	relRef(CharSequence ref) Working method: make a site root based link relative.
String	toString() State as String.

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

location

public final String location

The page's address.

This is the absolute or site root related (relative) URL, to which all other links should be related to.

If this denotation (finally set on construction) is null or empty the working method relRef(CharSequence) just returns the provided link, except for changing to lowerCase if so set.

See Also:

ank

isDir

public final boolean isDir

The page's address is a directory.

The criterion is (simply) the location's ending by \ oder /.

ank

public final String ank

The page's anchorage part.

A given anchor part (all beyond #) will be separated from location and stored including the # in ank. In ank the original case remains independent of lowerCase.

ank equals null means that this object was made with an address without anchor (see #make(address, lowerCase).

See Also:

relRef(CharSequence)

lowerCase

public final boolean lowerCase

All link specifications in lower case.

If true all link denotations will be considered and worked on in lower case.

Link denotations will be returned in lower case. The exception are mailto: links and anchors (beyond #); here the case is kept.

locationDepth

public final int locationDepth

Directory depth of location.

The depth is the number of the / respectively \ (file.separator) in location.
For network drives (//PD310S/xx/yy//zz) the starting double dashes don't count.

Method Detail

make

public static LocForRel make(CharSequence address,
                             boolean lowerCase)
                      throws IllegalArgumentException

Make a LocForRel object.

At the address denotation \ will be replaced by / and surrounding white space removed.

A leading http:// respectively https:// will be simply removed.
If ending in // the last / will be removed.
An anchor part if given (all beyond #) will be separated and stored in ank; the real address goes to location.

Parameters:

address - all other links will be related to it

lowerCase - true: All links will be considered and worked on in lower case; location will be stored in lower case

Throws:

IllegalArgumentException - on address errors

relRef

public String relRef(CharSequence ref)

Working method: make a site root based link relative.

The rationale is to use the same file or link denotation on different places without any adaption if they relate to the same base or common root even over different directory depths of HTML pages.

See above (class description).

toString

public String toString()

State as String.

Overrides:

toString in class Object

equals

public boolean equals(Object other)

Equality with other object.

If the other object is of type LocForRel and it is equal with location, lowerCase and ank it is regarded as equal.

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object