Evolving the Essbase Java API with JALE

I work with the Essbase Java API quite a bit. In fact, it’s more or less the reason that I picked up Java oh so many years ago. If you’re writing an app to do custom queries against a cube, need to develop a middle tier for your mobile app, or want to pull some cube stats, it’s the place to be. For me it’s a lot more useable than the C or VB APIs.

That being said, working with it can be a little challenging sometimes. Not because of inherent complexity, but because it was designed quite some time ago (especially in technology years) and before a lot of Java niceties came to be. In particular, there are iterators and other constructs that require a fair bit of boilerplate code to deal with. Here’s an example of getting a count of connections from the server:

public int getConnectionCount2(String username, String password, String server) {
	IEssbase essbase = null;
	IEssOlapServer olapServer = null;
	try {
		essbase = IEssbase.Home.create(IEssbase.JAPI_VERSION);
		olapServer = essbase.signOn(username, password, false, null, "embedded", server);
		IEssIterator connections = olapServer.getConnections();
		IEssBaseObject[] connectionInfoObjects = connections.getAll();
		logger.info("Connection count: {}", connectionInfoObjects.length);
		return connectionInfoObjects.length;
	} catch (EssException e) {
		logger.error("Essbase error: {}", e.getMessage());
		return -1;
	} finally {
		try {
		} catch (EssException e) {

Wow, that’s a lot of code – just to do something that’s ostensibly simple. We can’t realistically expect Oracle to overhaul their API. While it’s technically possible to create a new API (from Oracle’s standpoint) that’s also unlikely to happen. Unwieldy though it may be, it’s battle-tested and thorough (although a few of you out there are miffed that it doesn’t have support for varying attributes).

So if we can’t expect the API to be refactored and offer us some syntactic sugar, and can’t write a new API, what can we do? There’s another approach: wrap the API with another library with the express intent of making the Essbase Java API easier to use, less verbose, and leverage modern language features where it makes sense.

To that end, a side project of mine has been to create such a library, called the Java Antikythera Layer for Essbase (JALE). Here’s an example of some new code that can iterate the current Essbase connections. Note that this isn’t a direct replacement for the above since they do slightly different things:

public void testGetConnections() throws Exception {
	try (OlapServer server = Ess.create().signOnEmbedded(SERVER, USER, PASS)) {
		for (OlapConnectionInfo connInfo : server.getConnections()) {
			System.out.println("Conn info: " + connInfo);

Note that this is taken from a unit test in one of the projects I have for this little experiment of a library. As the library evolves more or as more people are interested I’ll post more samples and open up a GitHub repository. Some things to note about the above code-snippet and the design of the wrapper layer in general:

  1. Adds a convenience signOn method (signOnEmbedded) to make the intent of the method instantly understandable versus passing in a parameter called “embedded” as the current API requires.
  2. Drops the IEss prefix on classes/interfaces. Modern IDEs have reduced the need for this quasi-Hungarian notation.
  3. Instead of returning an an array of objects that need to be iterated and cast to their real types, a List of the expected object is returned (server.getConnections() returns the list).
  4. Java 7’s new “try-with-resources” construct is used and the JALE server object implements AutoClosable, obviating the need for a finally block here.
  5. Also note that JALE wraps the EssException in disconnect/signoff methods so we don’t need a dummy try block inside our finally block.
  6. Ess.create() is a convenience method that auto passed in the IEssBase.JAPI_VERSION static field. We can use an overloaded method if we need to call it with that parameter.
  7. The more astute of you out there may notice a couple of other things. :)

Internally, JALE has a utility library designed to help ease the implementation of replacement classes and call the right methods. Of particular note is an “IEssIterator” unroll method that is a veritable Swiss army knife for easily replacing the boilerplate code around the Essbase iterator. For example, check this bad boy out:

public class IteratorUtil {
	public static <E, F> List<F> iteratorToList(IEssIterator iterator, ConversionDelegate<E, F> delegate) throws EssException {
		List<F> objects = new ArrayList<F>();

		for (int index = 0; index < iterator.getCount(); index++) {
			E object = (E) iterator.getAt(index);
			F converted = delegate.convert(object);

		return objects;


Then in our wrapper for the traditional Essbase server object, we can do this:

public List<OlapApplication> getApps() throws EssException {
	return IteratorUtil.iteratorToList(olapServer.getApplications(), new ConversionDelegate<IEssBaseObject, OlapApplication>() {
		public OlapApplication convert(IEssBaseObject from) {
			return new IEssOlapApplicationWrapper((IEssOlapApplication) from);

Note that conversion delegate is a one method interface that just supports the generified convert method. It’s designed so we can just supply a lambda-esque convertion method block in the new method (in this case, getApps()) which in this case contains our logic for going from an IEssbaseObject to the designed type of OlapApplication (a new object in JALE).

Future Directions on JALE/a Hyperion Essbase API wrapper

There’s no timeline on a public release of JALE. At this point it’s highly experimental as I evaluate its feasibility. I am just implementing method as I need them, so don’t expect to see me wrapping the MDX routines any time soon (not that I don’t use them but it’s not a section of the API that “needs” much fixing). I’m not worried about a performance hit from wrapping the API but I do have some concerns about performance if there’s something in the native API that loads lazily or otherwise needs an active connection to the server that would cause things to act up when I wrap them an enumerate on them, for example.

As with all of my little side projects (particularly the open source variety), please let me know if you have any feedback or want to contribute. Unlike the others at this point, this one is very pre-alpha quality so I don’t have immediate plans to make it available, but jut wanted to discuss some of the things I am thinking of an working on.

Announcing Jolo, a Java library for printing text-based tables

Well, I’m at it again releasing another open-source project. I work with Hyperion and the Essbase Java API extensively, so it’s not uncommon for me to be doing things with grids and working on a command-line. I frequently write lightweight command-line clients to test things out. I didn’t love the options I was able to find in Java that would help print/format a text-based table. The ones I did find were clunky and hard to use.

So, you guessed it, I rolled my own. Jolo is a small and lightweight Java library with two goals: print out text-based tables, and have a tight and clean, yet flexible API. So let’s say we want to print out names, cities, and states in a three column table. The code looks like this:

public void testPrintTableWithColumns() {

    // setup table definition with column names/widths
    TableColumnList tcl = new TableColumnList.Builder()
        .add("Name", 40)
        .add("City", 15)
        .add("State", 2)

    // createRandomRows is a helper function in this case but would otherwise
    // be your data that is an Iterable<List<Something>>.
    Iterable<List<? extends Object>> data = createRandomRows(10, 3);

    // create the printer and print the data
    TablePrinter tp = new TablePrinter();
    tp.outputTable(tcl, data);

Having the TablePrinter separate from the concept of a TableColumnList is nice because we can plug-in different TablePrinter implementations if we want to. In the above example I have a helper method creating the data for me (createRandomRows()) but in your program this would be something that implements the Iterable interface and contains a List of something that extends Object. In Java parlance that means you can print anything that’s Iterable<List<? extends Object>> – note that the toString() method will be called, so you can pass anything in. If I get time I’ll enhance the API a bit to provide some convenience functions and syntactic sugar. Given some data, the above code generates this table:

|Name                                    |City           |St|
|Jason Jones                             |Seattle        |WA|
|Cameron Lackpour                        |Philadelphia   |PA|
|Tim Tow                                 |Huntsville     |AL|

Note that with a simple parameter in the builder we were able to constrain the width of a given column.

The Hyperion Connection

This isn’t ostensibly Hyperion- or Essbase-related (save for the names in my table, hehe), but if you work on the things that I work on then this might be up your alley. The Jolo page has more information including a link to the Github repository. I will likely push this to Maven Central as time permits to make its inclusion in anyone’s projects all the easier. Unlike many of my other projects, this one is not incredibly commented [yet], so that will be coming in the future weeks as time permits. The API is pretty clean though so you shouldn’t have a hard time using it. Licensed under the very business-friendly Apache Software License.

Kscope13 Session Thoughts: Joe Aultman sprinkles magic Groovy dust on the Essbase Java API

There were lots of great sessions this year, as always. I tried to get outside my comfort zone a little bit and take in some new content. I thought over the next few posts I’d shine a little bit of light on a few of the sessions that were notable to me.

Fixing What’s Broken in the Essbase JAPI and Reaching New Heights with Groovy

As a programmer, this was right up my alley, naturally. This session was presented by Joe Aultman. Joe is using Groovy to do some automation that would otherwise be done with the venerable Java API. Joe, if you’re reading this, super cool presentation. In my mind I saw this presentation as being about two things: issues with a particular API and issues with a language – namely a lot of “boilerplate” Java code.

As an aside, there is something of a renaissance happening in the Java world with respect to the JVM. As a computer science guy (go Dawgs!) and general purpose programming nerd I have been keeping abreast of this language and several others, particularly Clojure. In a nutshell, what’s going on is this: Sun (now Oracle, of course) created Java many years ago. Java runs inside the JVM, or Java Virtual Machine. Whereas with a language like C or C++ you might compile your C source code into an executable meant to run on a particular system, in Java you just always compile down to the same code that in turn runs on a JVM. In other words, in theory, as long as you have a JVM available for a platform (Windows, Linux, OS X, etc), then you should be able to run the same old byte code. Hence the original notion, “Write once, run everywhere.” In practice there were and are many quirks to this, but by and large the statement is true – which is why generally speaking you are able to download Java JAR and class files that work irrespective of the underlying operating system (rather than separate downloads for Linux, OS X, and so on).

As it turns out, the JVM is useful for more than just Java. New languages that are able to compile down to code than runs on the JVM are able to stand on the shoulders of giants and leverage an incredible amount of infrastructure that has already been written and battle tested. Some of the more notable languages running in the JVM are Groovy, Scala (kind of a streamlined Java), Clojure (a “Lisp” dialect), and Jython (Python running inside of a JVM).

Getting back to Joe’s presentation, I think it’s fair to say that Joe is enamored with what’s called “syntactic sugar” in the programming world. This essentially means that a language provides features or inherent abilities that reduce the need for verbose boilerplate code. Groovy more or less delivers the goods in this regard. Furthermore, Joe has created some idiomatic Groovy enhancements specifically for the Essbase Java API that reduce the need to include some “clutter code”.

I definitely liked what I saw, although as an apparently diehard Essbase Java API guy I don’t think I’ll be switching anytime soon (you’ll convert me yet, Joe!). If you didn’t make the presentation then definitely give his slides a look. Joe is working through the red tape in his legal department to be able to post his code under an open source license. Joe, if you haven’t picked a license yet, give me a call and I’ll help point you in the right direction if I can.

In any case, nice job on the presentation, man.

In other news, I have been working a little bit on the side on a wrapper for the Essbase Java API that repents for some of its sins and modernizes the usage a bit more. This is tentatively called Java Essbase Antikythera Layer (JEAL). If you use the Essbase Java API at all you might really like how this simplifies your life. It’s unfortunately a labor of love that I can’t dedicate a lot of time to so if you want to help please drop me a line!