Package com.storedobject.office.od

Class Office

java.lang.Object

com.storedobject.office.od.Office

public final class Office
extends Object

Utility class that provides methods for interacting with a LibreOffice or OpenOffice process for document creation, manipulation, and conversion. This class uses the UNO API to interface with the office process for operations such as opening documents, converting formats, and exporting to PDF or HTML.

This class is implemented as a singleton to manage a single office service instance. It ensures proper initialization, reuse of resources, and cleanup of the office service. The singleton instance is lazily initialized through get().

Thread-safety is guaranteed by synchronized blocks to ensure proper coordination between threads when accessing or initializing shared resources.

The class provides capabilities to:

 - Open and create new ODT (text document) and ODS (spreadsheet) files.
 - Convert documents to different formats such as PDF and HTML.
 - Manage lifecycle operations, including initialization and cleanup of office resources.

 Dependencies:
 - The LibreOffice or OpenOffice process must be installed and accessible.
 - The UNO runtime and related interfaces to communicate with office components.

 Error Handling:
 - Proper error handling is implemented to ensure exceptions such as initialization
   failures or IO errors are logged or thrown as needed.
 

Author:

Syam

Method Summary

Modifier and Type	Method	Description
static void	close(com.sun.star.lang.XComponent store)	Closes the given XComponent instance, releasing any associated resources.
static void	convertToHTML(InputStream in, OutputStream out)	Converts an input document from an InputStream into an HTML document and writes the resulting content to the specified OutputStream.
static void	convertToPDF(InputStream in, OutputStream out, PDFProperties pdfProperties)	Converts an input stream of document data into a PDF and writes the resulting content to the provided output stream.
static com.sun.star.lang.XComponent	createODS()	Creates a new OpenDocument Spreadsheet (ODS) document.
static com.sun.star.lang.XComponent	createODT()	Creates a new OpenDocument Text (ODT) document.
static Office	get()	Retrieves the singleton instance of the Office class, initializing it if necessary.
static com.sun.star.lang.XComponent	open(InputStream in)	Opens an XComponent from the provided InputStream.
static void	reset()	Resets the state of the Office class by performing cleanup and re-initialization.
static void	shutdown()	Shuts down the template-based reporting service.
static void	write(com.sun.star.lang.XComponent store, OutputStream out, PDFProperties pdfProperties)	Exports the content of an XComponent to a specified OutputStream in PDF format, optionally using provided PDFProperties for configuring export settings.

Methods inherited from class java.lang.Object

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

Method Details

get

public static Office get()

Retrieves the singleton instance of the Office class, initializing it if necessary. This method ensures that the Office instance is properly set up, re-initializing components like the server or the component loader if they are null or inactive.

Returns:

The singleton instance of the Office class.

reset

public static void reset()

Resets the state of the Office class by performing cleanup and re-initialization.

- Invokes the close() method to release any resources and shut down active components. - Calls the init() method to reinitialize the Office class, ensuring all necessary parts and services are properly set up. This method is often used to recover from errors or stale state by resetting and starting afresh.

createODS

public static com.sun.star.lang.XComponent createODS()
                                              throws Exception

Creates a new OpenDocument Spreadsheet (ODS) document. This method initializes and loads a default ODS document using the specified factory settings, ensuring it is hidden during the creation process.

Returns:

An XComponent representing the newly created ODS document.

Throws:

Exception - If the creation or loading of the ODS document fails.

createODT

public static com.sun.star.lang.XComponent createODT()
                                              throws Exception

Creates a new OpenDocument Text (ODT) document. This method initializes and loads a default ODT document using the specified factory settings, ensuring it is hidden during the creation process.

Returns:

An XComponent representing the newly created ODT document.

Throws:

Exception - If the creation or loading of the ODT document fails.

open

public static com.sun.star.lang.XComponent open(InputStream in)
                                         throws Exception

Opens an XComponent from the provided InputStream. This method converts the InputStream into a format compatible with the underlying Office framework and loads the component while ensuring it is initialized in a hidden state.

Parameters:

in - The InputStream containing the data to be opened as an XComponent.

Returns:

An XComponent representing the opened document or file.

Throws:

Exception - If an error occurs during the opening or conversion process.

close

public static void close(com.sun.star.lang.XComponent store)

Closes the given XComponent instance, releasing any associated resources. This method ensures proper cleanup of the provided component, either by invoking its close operation or by disposing of it directly, depending on its capabilities.

Parameters:

store - The XComponent instance to be closed. It can represent documents or other components managed by the Office framework.

write

public static void write(com.sun.star.lang.XComponent store,
 OutputStream out,
 PDFProperties pdfProperties)
                  throws Exception

Exports the content of an XComponent to a specified OutputStream in PDF format, optionally using provided PDFProperties for configuring export settings. This method requires the Office framework's initialization and throws an exception if it cannot initialize.

Parameters:

store - The XComponent representing the document or content to be exported.

out - The OutputStream where the content will be written in PDF format.

pdfProperties - An instance of PDFProperties containing optional settings such as filter type or export configurations. Can be null if no additional properties are required.

Throws:

Exception - If an error occurs during the export process, such as initialization failure, unsupported filter, or output stream issues.

convertToPDF

public static void convertToPDF(InputStream in,
 OutputStream out,
 PDFProperties pdfProperties)
                         throws Exception

Converts an input stream of document data into a PDF and writes the resulting content to the provided output stream. The conversion process utilizes specified PDF properties for configuration and formatting.

Parameters:

in - The InputStream containing the source document data to be converted. This stream is expected to be in a format that the underlying Office framework can process (e.g., ODT, DOC, XLS).

out - The OutputStream where the generated PDF content will be written. This stream must be writable and is where the output will be stored.

pdfProperties - An instance of PDFProperties containing optional settings for the PDF export process, such as page range or encryption. Can be null if no additional properties are required.

Throws:

Exception - If an error occurs during the conversion process, such as issues while opening the document, exporting to PDF, or writing to the output stream.

convertToHTML

public static void convertToHTML(InputStream in,
 OutputStream out)
                          throws Exception

Converts an input document from an InputStream into an HTML document and writes the resulting content to the specified OutputStream. The conversion process ensures that images are embedded within the HTML output.

Parameters:

in - The InputStream containing the source document to be converted. This input should be in a format supported by the underlying Office framework such as ODT or DOC.

out - The OutputStream where the generated HTML content will be written. This stream must be writable and will store the resulting HTML document.

Throws:

Exception - If an error occurs during initialization of the Office framework, the document conversion process, or the output stream operation.

shutdown

public static void shutdown()

Shuts down the template-based reporting service. This method performs the following actions:

 - Logs a message indicating the shutdown process has started.
 - Invokes the close() method to release resources and terminate active components.
 - Logs a message confirming that the service has been successfully stopped.
 

This method is typically used to ensure proper cleanup of the reporting service during application termination or when the service is no longer required.