* Only the instance need be constructed. The required mimetype, encoding, etc * will be copied across by this class. * * @return Returns a reader onto the location referenced by this instance. * The instance must always be a new instance. * @throws ContentIOException */ protected abstract ContentReader createReader() throws ContentIOException; /** * Performs checks and copies required reader attributes */ public final ContentReader getReader() throws ContentIOException { ContentReader reader = createReader(); if (reader == null) { throw new AlfrescoRuntimeException("ContentReader failed to create new reader: \n" + " reader: " + this); } else if (reader.getContentUrl() == null || !reader.getContentUrl().equals(getContentUrl())) { throw new AlfrescoRuntimeException("ContentReader has different URL: \n" + " reader: " + this + "\n" + " new reader: " + reader); } // copy across common attributes reader.setMimetype(this.getMimetype()); reader.setEncoding(this.getEncoding()); // done if (logger.isDebugEnabled()) { logger.debug("Reader spawned new reader: \n" + " reader: " + this + "\n" + " new reader: " + reader); } return reader; } /** * An automatically created listener sets the flag */ public synchronized final boolean isClosed() { if (channel != null) { return !channel.isOpen(); } else { return false; } } public synchronized boolean isChannelOpen() { if (channel != null) { return channel.isOpen(); } else { return false; } } /** * Provides low-level access to read content from the repository. *
* This is the only of the content reading methods that needs to be implemented
* by derived classes. All other content access methods make use of this in their
* underlying implementations.
*
* @return Returns a channel from which content can be read
* @throws ContentIOException if the channel could not be opened or the underlying content
* has disappeared
*/
protected abstract ReadableByteChannel getDirectReadableChannel() throws ContentIOException;
/**
* Create a channel that performs callbacks to the given listeners.
*
* @param directChannel the result of {@link #getDirectReadableChannel()}
* @param listeners the listeners to call
* @return Returns a channel
* @throws ContentIOException
*/
private ReadableByteChannel getCallbackReadableChannel(
ReadableByteChannel directChannel,
List
* All the content is streamed into memory. So, like the interface said,
* be careful with this method.
*
* @see ContentAccessor#getEncoding()
*/
public final String getContentString() throws ContentIOException
{
try
{
// read from the stream into a byte[]
InputStream is = getContentInputStream();
ByteArrayOutputStream os = new ByteArrayOutputStream();
FileCopyUtils.copy(is, os); // both streams are closed
byte[] bytes = os.toByteArray();
// get the encoding for the string
String encoding = getEncoding();
// create the string from the byte[] using encoding if necessary
String content = (encoding == null) ? new String(bytes) : new String(bytes, encoding);
// done
return content;
}
catch (IOException e)
{
throw new ContentIOException("Failed to copy content to string: \n" +
" accessor: " + this,
e);
}
}
}
OutputStream
*/
public final void getContent(OutputStream os) throws ContentIOException
{
try
{
InputStream is = getContentInputStream();
FileCopyUtils.copy(is, os); // both streams are closed
// done
}
catch (IOException e)
{
throw new ContentIOException("Failed to copy content to output stream: \n" +
" accessor: " + this,
e);
}
}
public final void getContent(File file) throws ContentIOException
{
try
{
InputStream is = getContentInputStream();
FileOutputStream os = new FileOutputStream(file);
FileCopyUtils.copy(is, os); // both streams are closed
// done
}
catch (IOException e)
{
throw new ContentIOException("Failed to copy content to file: \n" +
" accessor: " + this + "\n" +
" file: " + file,
e);
}
}
public final String getContentString(int length) throws ContentIOException
{
if (length < 0 || length > Integer.MAX_VALUE)
{
throw new IllegalArgumentException("Character count must be positive and within range");
}
Reader reader = null;
try
{
// just create buffer of the required size
char[] buffer = new char[length];
String encoding = getEncoding();
// create a reader from the input stream
if (encoding == null)
{
reader = new InputStreamReader(getContentInputStream());
}
else
{
reader = new InputStreamReader(getContentInputStream(), encoding);
}
// read it all, if possible
int count = reader.read(buffer, 0, length);
// there may have been fewer characters - create a new string
String result = new String(buffer, 0, count);
// done
return result;
}
catch (IOException e)
{
throw new ContentIOException("Failed to copy content to string: \n" +
" accessor: " + this + "\n" +
" length: " + length,
e);
}
finally
{
if (reader != null)
{
try { reader.close(); } catch (Throwable e) { logger.error(e); }
}
}
}
/**
* Makes use of the encoding, if available, to convert bytes to a string.
*