How to generate a JSON file from Mondrian output - mysql

Question

I am new to Mondrian. I am using it in my project for OLAP operations.
I am testing it with Foodmart database.
The problem is that I need the OLAP operations results in JSON format.
I know that mondrian has the same structure as JSON in the form of hierarchies.
I want to generate a JSON file as an output from the result of mondrian MDX query.
The result should be similar to OLAP operations.
I don't know how to iterate over the result generated from MDX query.
Here is the code.
String connStr = "Provider=mondrian;" +
"Catalog=/WEB-INF/FoodMart.xml;" +
"JdbcDrivers=com.mysql.jdbc.Driver;" +
"Jdbc=jdbc:mysql://localhost/foodmart;" +
"jdbcUser=root;" +
"jdbcPassword=;";
String queryStr ="select {[Measures].[Unit Sales], [Measures].[Store Cost], [Measures].>Store Sales]} ON COLUMNS,"+"Crossjoin(Hierarchize(Union({[Promotion Media].[All Media]}, >[Promotion Media].[All Media].Children)), {[Product].[All Products]})
ON ROWS"+" from [Sales]"+"where [Time].[1997]";
Connection connection = DriverManager.getConnection(connStr, null);
Query query = connection.parseQuery(queryStr);
Result result = connection.execute(query);
result.print(new PrintWriter(System.out));
Actually I need to perform OLAP operations on data warehouse which is stored in MySQL.
The resulted data should be in JSON format which I will pass to D3 http://mbostock.github.com/d3 for visualizations.
For data format I have to use JSON format.
Please any suggestions how to iterate MDX result and convert it in JSON file.
I am using Pentaho Mondrian for this purpose.
Thanks.

Answer 1

if you are working with PHP you could use this library to transform the xmla result into Json
http://www.ibm.com/developerworks/xml/library/x-xml2jsonphp/

Answer 2

Here's an example of what i suppose you want to do:
Class.forName("mondrian.olap4j.MondrianOlap4jDriver"); //load the driver
Connection connection = DriverManager.getConnection("Provider=mondrian;" +
"Catalog=/WEB-INF/FoodMart.xml;" +
"JdbcDrivers=com.mysql.jdbc.Driver;" +
"Jdbc=jdbc:mysql://localhost/foodmart;" +
"jdbcUser=root;" +
"jdbcPassword=;");
OlapWrapper wrapper = (OlapWrapper) connection;
OlapConnection olapConnection = wrapper.unwrap(OlapConnection.class);
CellSet cellSet = statement.executeOlapQuery(query);
CellSetAxis rows = cellSet.getAxes().get(1); //cube rows
CellSetAxis columns = cellSet.getAxes().get(0); //cube columns
int resultSize = rows.getPositionCount() * columns.getPositionCount();
String resultValues[] = new String[resultSize];
int valueIndex = 0;
for (Position row : rows) {
for (Position column : columns) {
Cell cell = cellSet.getCell(column, row);
String cellValue = cell.getFormattedValue();
resultValues[valueIndex++] = cellValue;
}
}
Gson gson = new Gson(); //gson library instance
String resultString = gson.toJson(responseValues); //json string
olapConnection.close();
connection.close();