ExcelUtil

Starts as the last row number of the sheet and looks up in the column to find the first non-null cell

Creates a sheet within the workbook with the name. If a sheet already exists with the same name then a new sheet with name sheetName_n, where n is the current number of sheets in the workbook is created. Sheet names must follow Excel naming conventions.

Assumes that the first row is a header for a CSV like file and returns the number of columns (1 for each header)

Assumes that the first row is a header for a CSV like file and returns the number of columns (1 for each header)

IO exceptions are squelched in this method. If there is a problem, then null is returned. Opens an Apache POI XSSFWorkbook instance. The user is responsible for closing the workbook when done. Do not try to write to the returned workbook.

Reads the Excel cell and translates it into a Java object

Reads the Excel cell and translates it into a String

Read a row assuming a fixed number of columns. Cells that are missing/null in the row are read as null objects.

Read a row assuming a fixed number of columns. Cells that are missing/null in the row are read as null Strings.

Read a row assuming a fixed number of columns. Cells that are missing/null in the row are read as null Strings.

This is the reverse operation to the function writeToExcel() for a Map The strings "+Infinity", "-Infinity", and "NaN" in the value column are correctly converted to the appropriate double representation. Any rows that have empty cells (null) are skipped in the processing.

Writes the Java Object to the Excel cell

Treats the columns as fields in a csv file, writes each row as a separate csv row in the resulting csv file

Writes each entry in the map to an Excel workbook. The mapping of problematic double values is as follows: