org.apache.maven.doxia.util
Class DoxiaUtils

java.lang.Object
  org.apache.maven.doxia.util.DoxiaUtils

public class DoxiaUtils
extends Object

General Doxia utility methods. The methods in this class should not assume any specific Doxia module or document format.

Since:

1.1

Version:

$Id: DoxiaUtils.java 1185112 2011-10-17 11:33:00Z ltheussl $

Author:

ltheussl

Method Summary

static String	byteToHex(byte b) Convert a byte to it's hexadecimal equivalent.
static String	encodeId(String id) Construct a valid Doxia id.
static String	encodeId(String id, boolean chop) Construct a valid Doxia id.
static MutableAttributeSet	getImageAttributes(String logo) Determine width and height of an image.
static boolean	isExternalLink(String link) Checks if the given string corresponds to an external URI, ie is not a link within the same document nor a relative link to another document (a local link) of the same site.
static boolean	isInternalLink(String link) Checks if the given string corresponds to an internal link, ie it is a link to an anchor within the same document.
static boolean	isLocalLink(String link) Checks if the given string corresponds to a relative link to another document within the same site, ie it is neither an internal nor an external link.
static boolean	isValidId(String text) Determines if the specified text is a valid id according to the rules laid out in encodeId(String).
static Date	parseDate(String str) Parses a string representing a date by trying different date patterns.

Methods inherited from class java.lang.Object

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

Method Detail

isInternalLink

public static boolean isInternalLink(String link)

Checks if the given string corresponds to an internal link, ie it is a link to an anchor within the same document. If link is not null, then exactly one of the three methods isInternalLink(java.lang.String), isExternalLink(java.lang.String) and isLocalLink(java.lang.String) will return true.

Parameters:

link - The link to check. Not null.

Returns:

True if the link starts with "#".

Throws:

NullPointerException - if link is null.

See Also:

isExternalLink(String), isLocalLink(String)

isExternalLink

public static boolean isExternalLink(String link)

Checks if the given string corresponds to an external URI, ie is not a link within the same document nor a relative link to another document (a local link) of the same site. If link is not null, then exactly one of the three methods isInternalLink(java.lang.String), isExternalLink(java.lang.String) and isLocalLink(java.lang.String) will return true.

Parameters:

link - The link to check. Not null.

Returns:

True if the link (ignoring case) starts with either "http:/", "https:/", "ftp:/", "mailto:", "file:/", or contains the string "://". Note that Windows style separators "\" are not allowed for URIs, see http://www.ietf.org/rfc/rfc2396.txt , section 2.4.3.

Throws:

NullPointerException - if link is null.

See Also:

isInternalLink(String), isLocalLink(String)

isLocalLink

public static boolean isLocalLink(String link)

Checks if the given string corresponds to a relative link to another document within the same site, ie it is neither an internal nor an external link. If link is not null, then exactly one of the three methods isInternalLink(java.lang.String), isExternalLink(java.lang.String) and isLocalLink(java.lang.String) will return true.

Parameters:

link - The link to check. Not null.

Returns:

True if the link is neither an external nor an internal link.

Throws:

NullPointerException - if link is null.

See Also:

isExternalLink(String), isInternalLink(String)

encodeId

public static String encodeId(String id)

Construct a valid Doxia id.

This method is equivalent to encodeId( id, false ).

Parameters:

id - The id to be encoded. May be null in which case null is returned.

Returns:

The trimmed and encoded id, or null if id is null.

See Also:

encodeId(java.lang.String, boolean)

encodeId

public static String encodeId(String id,
                              boolean chop)

Construct a valid Doxia id.

A valid Doxia id obeys the same constraints as an HTML ID or NAME token. According to the HTML 4.01 specification section 6.2 SGML basic types:

ID and NAME tokens must begin with a letter ([A-Za-z]) and may be followed by any number of letters, digits ([0-9]), hyphens ("-"), underscores ("_"), colons (":"), and periods (".").

According to XHTML 1.0 section C.8. Fragment Identifiers:

When defining fragment identifiers to be backward-compatible, only strings matching the pattern [A-Za-z][A-Za-z0-9:_.-]* should be used.

To achieve this we need to convert the id String. Two conversions are necessary and one is done to get prettier ids:

1. Remove whitespace at the start and end before starting to process
2. If the first character is not a letter, prepend the id with the letter 'a'
3. Any spaces are replaced with an underscore '_'
4. Any characters not matching the above pattern are either dropped, or replaced according to the rules specified in the HTML specs.

For letters, the case is preserved in the conversion.

Here are some examples:

 DoxiaUtils.encodeId( null )        = null
 DoxiaUtils.encodeId( "" )          = "a"
 DoxiaUtils.encodeId( "  " )        = "a"
 DoxiaUtils.encodeId( " _ " )       = "a_"
 DoxiaUtils.encodeId( "1" )         = "a1"
 DoxiaUtils.encodeId( "1anchor" )   = "a1anchor"
 DoxiaUtils.encodeId( "_anchor" )   = "a_anchor"
 DoxiaUtils.encodeId( "a b-c123 " ) = "a_b-c123"
 DoxiaUtils.encodeId( "   anchor" ) = "anchor"
 DoxiaUtils.encodeId( "myAnchor" )  = "myAnchor"
 

Parameters:

id - The id to be encoded. May be null in which case null is returned.

chop - true if non-ASCII characters should be ignored. If false, any non-ASCII characters will be replaced as specified above.

Returns:

The trimmed and encoded id, or null if id is null. If id is not null, the return value is guaranteed to be a valid Doxia id.

Since:

1.1.1

See Also:

isValidId(java.lang.String)

byteToHex

public static String byteToHex(byte b)

Convert a byte to it's hexadecimal equivalent.

Parameters:

b - the byte value.

Returns:

the result of Integer.toHexString( b & 0xFF ).

Since:

1.1.1

isValidId

public static boolean isValidId(String text)

Determines if the specified text is a valid id according to the rules laid out in encodeId(String).

Parameters:

text - The text to be tested. May be null in which case false is returned.

Returns:

true if the text is a valid id, otherwise false.

See Also:

encodeId(String)

parseDate

public static Date parseDate(String str)
                      throws ParseException

Parses a string representing a date by trying different date patterns.

The following date patterns are tried (in the given order):

"yyyy-MM-dd", "yyyy/MM/dd", "yyyyMMdd", "yyyy", "dd.MM.yyyy", "dd MMM yyyy",
  "dd MMM. yyyy", "MMMM yyyy", "MMM. dd, yyyy", "MMM. yyyy", "MMMM dd, yyyy",
  "MMM d, ''yy", "MMM. ''yy", "MMMM ''yy"

A parse is only sucessful if it parses the whole of the input string. If no parse patterns match, a ParseException is thrown.

As a special case, the strings "today" and "now" (ignoring case) return the current date.

Parameters:

str - the date to parse, not null.

Returns:

the parsed date, or the current date if the input String (ignoring case) was "today" or "now".

Throws:

ParseException - if no pattern matches.

NullPointerException - if str is null.

Since:

1.1.1.

getImageAttributes

public static MutableAttributeSet getImageAttributes(String logo)
                                              throws IOException

Determine width and height of an image. If successful, the returned SinkEventAttributes contain width and height attribute keys whose values are the width and height of the image (as a String).

Parameters:

logo - a String containing either a URL or a path to an image file. Not null.

Returns:

a set of SinkEventAttributes, or null if no ImageReader was found to read the image.

Throws:

IOException - if an error occurs during reading.

NullPointerException - if logo is null.

Since:

1.1.1