Krishnan Viswanath's Blog

Krishan Viswanath is currently working for JP Morgan Chase & Co. in Kansas City, MO. He has over 10 years of experience in IT area.

Open Office Java API

// get the remote office component context
xContext = com.sun.star.comp.helper.Bootstrap.bootstrap();
System.out.println("Connected to a running office ...");

// Get the remote office service manager
XMultiComponentFactory xMCF = xContext.getServiceManager();

// Get the root frame (i.e. desktop) of openoffice framework.
Object oDesktop = xMCF.createInstanceWithContext("com.sun.star.frame.Desktop", xContext);

// Desktop has 3 interfaces. The XComponentLoader interface provides ability to load
// components.
XComponentLoader xCompLoader = (XComponentLoader)
		UnoRuntime.queryInterface(com.sun.star.frame.XComponentLoader.class, oDesktop);

// URL of the component to be loaded
String sUrl = "file:///[file name]";

// Load the document, which will be displayed. More param info in apidoc
XComponent xComp = xCompLoader.loadComponentFromURL(sUrl, "_blank", 0, new PropertyValue[0]);

// Get the textdocument
XTextDocument aTextDocument = (XTextDocument)UnoRuntime.queryInterface(
                  com.sun.star.text.XTextDocument.class, xComp);

// Query the XTextTablesSupplier interface from our document
XTextTablesSupplier xTablesSupplier = (XTextTablesSupplier) UnoRuntime.queryInterface(
                 XTextTablesSupplier.class, aTextDocument );

// Get the tables collection
XNameAccess xNamedTables = xTablesSupplier.getTextTables();

// Query the XIndexAccess from the tables collection
XIndexAccess xIndexedTables = (XIndexAccess) UnoRuntime.queryInterface(
                 XIndexAccess.class, xNamedTables);

for (int i = 0; i < xIndexedTables.getCount(); i++) {
  Object table = xIndexedTables.getByIndex(i);
  XTextTable xTable = (XTextTable) UnoRuntime.queryInterface(
                  XTextTable.class, table);

  // Getting Table Rows
  XTableRows xRows = xTable.getRows();

  // Getting the right Table Cell (Hard Coded as B2).
   XText xCellText = (XText) UnoRuntime.queryInterface (
                  XText.class, xTable.getCellByName ( "B2" ) );

   // Make JDBC calls. Perform data tranformation and set it
   xCellText.setString("Hello Worlds");
}

// URL where the document is to be stored
String storeUrl = "file:///Test_97.rtf";

XStorable xStorable = (XStorable)UnoRuntime.queryInterface(XStorable.class, aTextDocument);
PropertyValue[] storeProps = new PropertyValue[1];
storeProps[0] = new PropertyValue();
storeProps[0].Name = "FilterName";
storeProps[0].Value = "Rich Text Format";

xStorable.storeAsURL(storeUrl, storeProps);

XPrintable xPrintable = (XPrintable)UnoRuntime.queryInterface(XPrintable.class, aTextDocument);
PropertyValue[] printerDesc = new PropertyValue[1];
printerDesc[0] = new PropertyValue();
printerDesc[0].Name = "Name";
printerDesc[0].Value = "PDFCreator";
xPrintable.setPrinter(printerDesc);

PropertyValue[] printOpts = new PropertyValue[1];
printOpts[0] = new PropertyValue();
printOpts[0].Name = "Pages";
printOpts[0].Value = "1";
xPrintable.print(printOpts);

Dealing with Command Line Parameters

One of the things that keep popping up often is a need to write batch programs that is started from command line. Every single time its always been either reinvent the wheel or copy/paste from old code. So recently decided to put an end to this practice by looking at CLI solution from Apache.


CLI is a really nice utility and could be a potential enterprise reusable component. However while dealing with CLI, one will soon discover the verbosity especially while dealing with OptionBuilder
class. This means we are reverting back to old manner of programming (cut/paste) but in style.

But one could externalize this in a XML by hiding the plumbing of CLI that deals with verbosity. A simple framework around CLI framework would do this trick and this means a developer who wants to use CLI would write this simple XML


<cli-map>
   <cli-parser>org.apache.commons.cli.GnuParser</cli-parser>
   <cli-domain-obj>com.util.cli.domain.CommandObj</cli-domain-obj>
   <help>
    <help-formatter>org.apache.commons.cli.HelpFormatter</help-formatter>
      <print-help>true</print-help>
    <syntax-tip>java com.util.cli.TestDrive blah blah </syntax-tip>
   </help>
   <options>
            <option optName="file"  withArgName="file" 
        hasArgs="true" withDescription="use given file for log" />
            <option optName="logger" withArgName="classname"
        hasArgs="true" withDescription="the class which it to perform logging" />
            <option optName="listener" withArgName="classname"
        hasArgs="true" withDescription="add an instance of class as a project listener" />
            <option optName="buildfile" withArgName="file"
        hasArgs="true" withDescription ="use given buildfile" />
            <option optName="file" withArgName="file"
        hasArgs="true" withDescription="search for buildfile towards the root of the filesystem and use it" />
            <option optName="D" withArgName="property=value" 
    hasArgs="true" withValueSeparator="=" withDescription ="use value for given property" />
    </options>
</cli-map>


The com.util.cli.domain.CommandObj needs to have instance variables that is same as optName. Then, using reflection and XML processing one could do bulk of the CLI plumbing to figure out what the values are. The outcome of this simple exercise - No more need to go through drudgery of writing code to parse command line arguments.
Write a simple XML, create a POJO, and get values populated in the POJO that is needed for the batch program with just three lines of code.


String fileName = "cli-map.xml";
CommandProcessorExt cmdProcessor = new CommandProcessorExt(fileName);
CommandObj obj = (CommandObj)cmdProcessor.process(args);

Better yet, Commons Configuration could be used to implement something similar! too...
Of course if some one is interested in the rudimentary, but working, source code, please feel free to ping!

December 2005

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Open Office Java API

Dealing with Command Line Parameters

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