public DelayedRefreshSourceWrapper(Source source,
    long delay) 
{
                                           
        this.source = source;
        this.delay = delay;
        this.isModifiableSource = source instanceof ModifiableSource;
}

Creates a wrapper for a Source which ensures that Source.getLastModified() won't be called more than once per delay milliseconds period.

Parameters:

source - the wrapped Source

delay - the last-modified refresh delay, in milliseconds

 public final long getContentLength() 
{
        return this.source.getContentLength();
}

 public final InputSource getInputSource() throws IOException, ProcessingException 
{
        return this.source.getInputSource();
}

 public final InputStream getInputStream() throws IOException, ProcessingException 
{
        return this.source.getInputStream();
}

 public final long getLastModified() 
{
        // Do we have to refresh the source ?
        if (System.currentTimeMillis()  >= nextCheckTime) {
            // Yes
            this.refresh();
        }
        return this.lastModified;
}

Get the last modification time for the wrapped Source. The age of the returned information is guaranteed to be lower than or equal to the delay specified in the constructor.

This method is also thread-safe, even if the underlying Source is not.

 public final String getSystemId() 
{
        return this.source.getSystemId();
}

 public final  void recycle() 
{
        this.source.recycle();
}

 public final synchronized  void refresh() 
{
        this.nextCheckTime = System.currentTimeMillis() + this.delay;
        // Refresh modifiable sources
        if (this.isModifiableSource) {
            ((ModifiableSource)this.source).refresh();
        }
        // Keep the last modified date
        this.lastModified = source.getLastModified();
}

Force the refresh of the wrapped Source, even if the refresh period isn't over, and starts a new period.

This method is thread-safe, even if the underlying Source is not.

 public final  void toSAX(ContentHandler handler) throws SAXException 
{
        this.source.toSAX(handler);
}