Package com.storedobject.core

Interface ContentProducer

All Superinterfaces:

ContentType, Executable, RequiresTransactionManager, Runnable

All Known Implementing Classes:

AbstractODTReport, AbstractSpreadSheet, AccountStatement, CombinedPDFReport, Content, CSVReport, DataDownload, Excel, ExcelReport, FileCirculationStatus, FileContent, FileExpiryReport, ImageProducer, ItemMovementReport, IteratorODTReport, JournalReport, ObjectGridReport, ObjectList, ObjectListExcel, ODS, ODSReport, ODT, ODTObjectReport, ODTReport, PDF, PDFContent, PDFObjectReport, PDFReport, StockAvailability, StockMovementReport, StockReport, StockReportExcel, StreamContentProducer, StreamDataContent, SVGContentGenerator, TextContentProducer, TextReport, TrialBalance

public interface ContentProducer
extends Executable, ContentType, RequiresTransactionManager

The ContentProducer interface defines a contract for producing and managing content. It supports functionality for generating content, handling file-related metadata, managing transactions, and providing stream-based access to the content. ContentProducer implementations may handle content generation processes, error handling, and saving content to file storage.

Author:

Syam

Method Summary

Modifier and Type	Method	Description
default void	abort(Throwable error)	This method may be called when the content generation is aborted due to some error.
default void	execute()	Executes the operation associated with the content producer.
default InputStream	extractContent()	Extracts and retrieves the content as an InputStream.
InputStream	getContent()	Retrieves the content as an InputStream.
default Entity	getEntity()	Retrieves the Entity associated with the current context.
default Throwable	getError()	Get the current error (set via abort(Throwable)).
String	getFileExtension()	Retrieves the file extension associated with the content.
String	getFileName()	Retrieves the name of the file associated with the content.
default StreamData	getStreamData()	Creates and returns a new instance of StreamData, populating it with the content type and stream data provider associated with this instance.
default StreamDataProvider	getStreamDataProvider()	Retrieves a default implementation of the StreamDataProvider.
default SystemEntity	getSystemEntity()	Retrieves the system entity associated with the current transaction manager.
default TransactionManager	getTransactionManager()	Retrieves the transaction manager associated with this object.
void	produce()	Certain types of content may have to be produced.
default void	ready()	Signals that the content is ready to consume.
default FileData	saveTo(FileData fileData, Transaction transaction)	Saves the given FileData instance using the content produced by this instance and associates it with the specified Transaction.
default FileData	saveTo(FileData fileData, TransactionManager tm)	Saves the given FileData instance using the content produced by this instance and associates it with the specified TransactionManager.
default FileData	saveTo(String folderPath, Transaction transaction)	Saves the content produced by this instance to the specified folder path and associates it with the provided transaction.
default FileData	saveTo(String folderPath, TransactionManager tm)	Saves the current content to a specified folder path using the provided TransactionManager.

Methods inherited from interface com.storedobject.core.ContentType

getContentType, getLink, getMimeType, isAudio, isHTML, isImage, isLink, isMedia, isPDF, isText, isVideo

Methods inherited from interface com.storedobject.common.Executable

act, run

Methods inherited from interface com.storedobject.core.RequiresTransactionManager

setTransactionManager

Method Details

produce

void produce()

Certain types of content may have to be produced. This method is used to do that.

getContent

InputStream getContent()
                throws Exception

Retrieves the content as an InputStream.

Note: This may not invoke produce() and it may just return the content if it is already available. It is implementation-dependent.

Returns:

an InputStream representing the content. This may be null if the content is not yet available.

Throws:

Exception - if there is an error during content retrieval

getFileExtension

String getFileExtension()

Retrieves the file extension associated with the content.

Returns:

a String representing the file extension, or an empty string if no extension is available.

getFileName

String getFileName()

Retrieves the name of the file associated with the content.

Returns:

a String representing the name of the file, or null if the file name is unavailable.

ready

default void ready()

Signals that the content is ready to consume. The exact behavior or implications of this readiness state are dependent on the implementation.

getTransactionManager

default TransactionManager getTransactionManager()

Description copied from interface: RequiresTransactionManager

Retrieves the transaction manager associated with this object.

Specified by:

getTransactionManager in interface RequiresTransactionManager

Returns:

the transaction manager responsible for managing transaction boundaries

getSystemEntity

default SystemEntity getSystemEntity()

Retrieves the system entity associated with the current transaction manager. This method checks if a TransactionManager instance is available and, if so, retrieves the associated SystemEntity. If no transaction manager is available, it returns null.

Returns:

the SystemEntity associated with the current transaction manager, or null if the transaction manager is not available.

getEntity

default Entity getEntity()

Retrieves the Entity associated with the current context. This method internally checks for a SystemEntity using getSystemEntity(), and if it exists, retrieves the corresponding Entity.

Returns:

an Entity object if a SystemEntity is available and associated with an Entity, or null if no such association exists.

extractContent

default InputStream extractContent()
                            throws Exception

Extracts and retrieves the content as an InputStream. If the content is not immediately available, this method triggers the production of the content in a separate virtual thread and waits for the content to become available.

Returns:

an InputStream representing the extracted content, or null if the content cannot be produced or retrieved.

Throws:

Exception - if there is an error during content production or retrieval.

getStreamDataProvider

default StreamDataProvider getStreamDataProvider()

Retrieves a default implementation of the StreamDataProvider. The returned StreamDataProvider suitable for saving content to the database via StreamData.

Returns:

An instance of StreamDataProvider tailored to provide data of this producer for saving to the database.

getStreamData

default StreamData getStreamData()

Creates and returns a new instance of StreamData, populating it with the content type and stream data provider associated with this instance.

Returns:

an instance of StreamData containing the content type and stream data provider of this producer.

execute

default void execute()

Executes the operation associated with the content producer. This method serves as the entry point for triggering the production of content. The implementation calls the produce() method to perform the content production.

Specified by:

execute in interface Executable

saveTo

default FileData saveTo(String folderPath,
 Transaction transaction)
                 throws Exception

Saves the content produced by this instance to the specified folder path and associates it with the provided transaction. The content is retrieved using the StreamData generated by this instance.

Parameters:

folderPath - The folder path where the content should be saved. This must be a valid directory path of the SO platform database.

transaction - The transaction to associate with the saved content.

Returns:

A FileData object representing the saved file, including metadata and a reference to the stored content.

Throws:

Exception - If an error occurs during the save operation, such as invalid parameters, failure during content production, or failure to save the data to the provided path.

saveTo

default FileData saveTo(FileData fileData,
 Transaction transaction)
                 throws Exception

Saves the given FileData instance using the content produced by this instance and associates it with the specified Transaction. The process involves generating a StreamData object, saving it, assigning it to the provided FileData instance, and then saving the FileData itself.

Parameters:

fileData - The FileData object to save. This object will be populated with the produced content and metadata during the operation.

transaction - The Transaction to associate with the save operation.

Returns:

The updated FileData object containing the saved content and metadata.

Throws:

Exception - If an error occurs during the save operation, such as failure to generate or save the StreamData, or issues related to the Transaction.

saveTo

default FileData saveTo(String folderPath,
 TransactionManager tm)
                 throws Exception

Saves the current content to a specified folder path using the provided TransactionManager. This method handles the transaction lifecycle, including committing or rolling back in case of exceptions. The content is saved by creating a StreamData object retrieved from this producer, associating it with the transaction, and then saving it to the given folder path in the SO platform database.

Parameters:

folderPath - The folder path where the content should be saved. It must be a valid directory path.

tm - The TransactionManager used to manage the transaction during the save operation.

Returns:

A FileData object representing the saved file, including metadata and a reference to the stored content.

Throws:

Exception - If an error occurs during the save operation, including invalid parameters, transaction creation failure, failure in content production, or writing issues.

saveTo

default FileData saveTo(FileData fileData,
 TransactionManager tm)
                 throws Exception

Saves the given FileData instance using the content produced by this instance and associates it with the specified TransactionManager. This method manages the transaction lifecycle and delegates the actual save operation to the underlying transaction.

Parameters:

fileData - The FileData object to save. This object will be populated with the produced content and metadata during the operation.

tm - The TransactionManager used to manage the transaction during the save operation. Ensures proper transaction handling, including rollback in case of failure.

Returns:

The updated FileData object containing the saved content and metadata.

Throws:

Exception - If an error occurs during the save operation, including errors in transaction handling, content generation, or saving process.

abort

default void abort(Throwable error)

This method may be called when the content generation is aborted due to some error.

Note: This could be invoked multiple times.

Parameters:

error - Error.

getError

default Throwable getError()

Get the current error (set via abort(Throwable)).

Returns:

Current error, if any.