Aspose.Slides for Java provides class library to handle PowerPoint 2003 (PPT) as well as PowerPoint 2007 (PPTX) files, whereas Aspose.Cells for Java provides class library to handle MS Excel features including Excel charts. So, in order to work with presentations alongwith charts, both Aspose.Slides for Java and Aspose.Cells for Java are to be used. That is, Excel Charts will be created using Aspose.Cells for Java and these charts can be embedded as OLE Object in presentation using Aspose.Slides for Java.
1) A complete example to create charts in MS Excel and embed them in MS PowerPoint 2003 docs can be found here.
2) The same example can be implemented for MS PowerPoint 2007. However, there is an issue with SlideEx.getShapes.addOleObjectFrame() method which is supposed to embed an OLE Object in PPTX docs, whereas Slide.getShapes.addOleObjectFrame() which is supposed to do the same for PPT docs is working fine. This issue has been reported as 13265 for a fix by our product development team. This thread has been associated with this issue so that you can be autoresponded as soon as it is resolved.
3) For known issues against Aspose.Slides for Java, please visit here.