org.w3c.rdfpic.core
Class ImgMetaHandler

java.lang.Object
  |
  +--org.w3c.rdfpic.core.ImgMetaHandler

public class ImgMetaHandler

extends java.lang.Object

A class to get and send meta (text) data to image files. (Currently jpeg's only)

Field Summary

(package private) java.awt.Image	currentImg
(package private) ImgMeta	im
(package private) ProtocolHandler	ph
(package private) java.net.URL	url

Constructor Summary

ImgMetaHandler()

Method Summary

boolean	canRead() Returns whether the image is readable.
boolean	canWrite() Returns whether the image is writable.
int	getFileSize() Returns the size of the image file loaded in bytes.
java.awt.Image	getImg() Returns a (cached) Image of the graphical data of the file currently loaded.
java.net.URL	getURL() Returns the active URL.
java.lang.String	read() Reads the text embedded in the file.
void	setURL(java.net.URL url) Selects (and fully buffers!) an image.
void	write(java.lang.String comment) (Over)writes the text embedded in the file.

Methods inherited from class java.lang.Object

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

Field Detail

url

java.net.URL url

ph

ProtocolHandler ph

im

ImgMeta im

currentImg

java.awt.Image currentImg

Constructor Detail

ImgMetaHandler

public ImgMetaHandler()

Method Detail

setURL

public void setURL(java.net.URL url)
            throws PHException,
                   UnknownImgTypeException

Selects (and fully buffers!) an image.

Parameters:

url - The url of the image. Supports whatever ProtocolHandler does (currently http 1.1 and file protocols)

getImg

public java.awt.Image getImg()

Returns a (cached) Image of the graphical data of the file currently loaded. Returns null if nothing is loaded.

getFileSize

public int getFileSize()
                throws PHException

Returns the size of the image file loaded in bytes.

Throws:

PHException - when no file is loaded.

getURL

public java.net.URL getURL()

Returns the active URL. (Not a copy - so do not change!)

read

public java.lang.String read()
                      throws java.io.IOException

Reads the text embedded in the file.

write

public void write(java.lang.String comment)
           throws java.io.IOException

(Over)writes the text embedded in the file.

Parameters:

comment - The comment to embed.

canRead

public boolean canRead()

Returns whether the image is readable.

canWrite

public boolean canWrite()

Returns whether the image is writable. Because of limitations in HTTP 1.1, it's impossible to know in advance whether PUT permissions will be granted. So, if HTTP 1.1 is being used, is simply assumes it can write, but signals an IO error when you actually try to.