Introduction to GroupDocs.Assembly for Java GroupDocs.Assembly for Java is a Java API engine designed to generate documents based on templates. In essence, the engine accepts a template document and some data, assembles data with the template document as per syntax defined by the template document and then, generates the output document in the template’s format or in the specified output format. Since GroupDocs.Assembly for Java can generate documents based on a data source, essentially it serves two purposes: Document Automation and Report Generation....OTT) Spreadsheet (XLS, XLSX, XLSM, XLTX, XLTM, XLSB, SpreadsheetML...Supported Spreadsheet (XLS, XLSX, XLSM, XLTX, XLTM, XLSB, SpreadsheetML...