How to get chart info from an Excel spreadsheet using Apache POI?

There isn't a high level representation at the moment, so you'll need to drop down into the xmlbeans level and work with the low level CT* objects.

For Chart Sheets, there's XSSFChartSheet which will give you a CTChartsheet object, which has a little bit of info.

For both XSSFChart and XSSFChartSheet (regular and chart sheets), you'll need to go via the drawings to get the charts. Each sheet with charts on it should have one Drawing, and the charts get linked from the drawing, rather than the sheet itself.

As of r1090442 (so POI 3.8 or newer), there's a method on XSSFDrawing to give you all the XSSFChart objects (which are wrappers around the /charts/chart#.xml part). If you're on a really really old version of POI, use the CTDrawing to get the details of the chart, grab the /charts/chart#.xml part that corresponts, and then have xmlbeans give you the CT objects for it. Either way that'll let you get the titles, types, data ranges etc.

It is a bit fiddly though, so do please consider sending in a patch to POI if you get something good worked out for working with the CTChart objects!

you can read chart data as XML using XSSFDrawing

like

 XSSFDrawing drawing = ((XSSFSheet)sheet).createDrawingPatriarch();        System.out.println(drawing.getCTDrawing().toString());

will print whole chart as XMl and also using

drawing.getCharts();

you can add Iterator to it to browse chart

I don't know the exact answer to your question, but the OpenXML SDK 2.0 comes with a DocumentReflector.exe tool that will show you exactly how the chart is defined (including all relationships between the SpreadsheetML and the DrawingML packages). There is some more info on this tool in this article.