org.dspace.app.sitemap
Class AbstractGenerator

java.lang.Object
  org.dspace.app.sitemap.AbstractGenerator

Direct Known Subclasses:

HTMLSitemapGenerator, SitemapsOrgGenerator

public abstract class AbstractGenerator
extends Object

Base class for creating sitemaps of various kinds. A sitemap consists of one or more files which list significant URLs on a site for search engines to efficiently crawl. Dates of modification may also be included. A sitemap index file that links to each of the sitemap files is also generated. It is this index file that search engines should be directed towards.

Provides most of the required functionality, subclasses need just implement a few methods that specify the "boilerplate" and text for including URLs.

Typical usage:

   AbstractGenerator g = new FooGenerator(...);
   while (...) {
     g.addURL(url, date);
   }
   g.finish();
 

Author:

Robert Tansley

Field Summary

protected int	bytesWritten Number of bytes written to current file
protected PrintStream	currentOutput Current output
protected int	fileCount Number of files written so far
protected File	outputDir Directory files are written to
protected int	urlsWritten Number of URLs written to current file

Constructor Summary

AbstractGenerator(File outputDirIn)
Initialize this generator to write to the given directory.

Method Summary

void	addURL(String url, Date lastMod) Add the given URL to the sitemap.
protected void	closeCurrentFile() Finish with the current sitemap file.
int	finish() Complete writing sitemap files and write the index files.
abstract String	getFilename(int number) Return the filename a sitemap at the given index should be stored at.
abstract String	getIndexFilename() Get the filename the index should be written to.
abstract String	getLeadingBoilerPlate() Return the boilerplate at the top of a sitemap file.
abstract int	getMaxSize() Return the maximum size in bytes that an individual sitemap file should be.
abstract int	getMaxURLs() Return the maximum number of URLs that an individual sitemap file should contain.
abstract String	getTrailingBoilerPlate() Return the boilerplate at the end of a sitemap file.
abstract String	getURLText(String url, Date lastMod) Return marked-up text to be included in a sitemap about a given URL.
protected void	startNewFile() Start writing a new sitemap file.
abstract boolean	useCompression() Return whether the written sitemap files and index should be GZIP-compressed.
abstract void	writeIndex(PrintStream output, int sitemapCount) Write the index file.

Methods inherited from class java.lang.Object

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

Field Detail

fileCount

protected int fileCount

Number of files written so far

bytesWritten

protected int bytesWritten

Number of bytes written to current file

urlsWritten

protected int urlsWritten

Number of URLs written to current file

outputDir

protected File outputDir

Directory files are written to

currentOutput

protected PrintStream currentOutput

Current output

Constructor Detail

AbstractGenerator

public AbstractGenerator(File outputDirIn)

Initialize this generator to write to the given directory. This must be called by any subclass constructor.

Parameters:

outputDirIn - directory to write sitemap files to

Method Detail

startNewFile

protected void startNewFile()
                     throws IOException

Start writing a new sitemap file.

Throws:

IOException - if an error occurs creating the file

addURL

public void addURL(String url,
                   Date lastMod)
            throws IOException

Add the given URL to the sitemap.

Parameters:

url - Full URL to add

lastMod - Date URL was last modified, or null

Throws:

IOException - if an error occurs writing

closeCurrentFile

protected void closeCurrentFile()
                         throws IOException

Finish with the current sitemap file.

Throws:

IOException - if an error occurs writing

finish

public int finish()
           throws IOException

Complete writing sitemap files and write the index files. This is invoked when all calls to addURL(String, Date) have been completed, and invalidates the generator.

Returns:

number of sitemap files written.

Throws:

IOException - if an error occurs writing

getURLText

public abstract String getURLText(String url,
                                  Date lastMod)

Return marked-up text to be included in a sitemap about a given URL.

Parameters:

url - URL to add information about

lastMod - date URL was last modified, or null if unknown or not applicable

Returns:

the mark-up to include

getLeadingBoilerPlate

public abstract String getLeadingBoilerPlate()

Return the boilerplate at the top of a sitemap file.

Returns:

The boilerplate markup.

getTrailingBoilerPlate

public abstract String getTrailingBoilerPlate()

Return the boilerplate at the end of a sitemap file.

Returns:

The boilerplate markup.

getMaxSize

public abstract int getMaxSize()

Return the maximum size in bytes that an individual sitemap file should be.

Returns:

the size in bytes.

getMaxURLs

public abstract int getMaxURLs()

Return the maximum number of URLs that an individual sitemap file should contain.

Returns:

the maximum number of URLs.

useCompression

public abstract boolean useCompression()

Return whether the written sitemap files and index should be GZIP-compressed.

Returns:

true if GZIP compression should be used, false otherwise.

getFilename

public abstract String getFilename(int number)

Return the filename a sitemap at the given index should be stored at.

Parameters:

number - index of the sitemap file (zero is first).

Returns:

the filename to write the sitemap to.

getIndexFilename

public abstract String getIndexFilename()

Get the filename the index should be written to.

Returns:

the filename of the index.

writeIndex

public abstract void writeIndex(PrintStream output,
                                int sitemapCount)
                         throws IOException

Write the index file.

Parameters:

output - stream to write the index to

sitemapCount - number of sitemaps that were generated

Throws:

IOException - if an IO error occurs