Using custom colors with SXSSF (Apache POI)
To avoid the need of typecast for the cellStyles, create first a XSSFWorkbook with cellStyles (XSSFCellStyle) applying the custom colors and then wrap it with a SXSSFWorkbook constructor like the sample below:
/**
* Sample based on POI <a href="http://poi.apache.org/spreadsheet/how-to.html#sxssf">Spreadsheet How-To</a>.
*
* @see <a href="https://poi.apache.org/apidocs/org/apache/poi/xssf/streaming/SXSSFWorkbook.html">SXSSFWorkbook</a>
*/
public static void main(String[] args) throws Throwable {
XSSFWorkbook xssfWorkbook = new XSSFWorkbook();
XSSFColor colorGrey = new XSSFColor(new Color(210, 210, 210));
XSSFCellStyle cellStyleGrey = xssfWorkbook.createCellStyle();
cellStyleGrey.setFillPattern(CellStyle.SOLID_FOREGROUND);
cellStyleGrey.setFillForegroundColor(colorGrey);
// keep 100 rows in memory, exceeding rows will be flushed to disk
SXSSFWorkbook sxssfWorkbook = new SXSSFWorkbook(xssfWorkbook, 100);
Sheet sheet = sxssfWorkbook.createSheet();
for (int rownum = 0; rownum < 1000; rownum++) {
Row row = sheet.createRow(rownum);
for (int cellnum = 0; cellnum < 10; cellnum++) {
Cell cell = row.createCell(cellnum);
String address = new CellReference(cell).formatAsString();
cell.setCellValue(address);
// for even rows apply the grey cellStyle
if (rownum % 2 == 0) {
cell.setCellStyle(cellStyleGrey);
}
}
}
// Omitted asserts block from original sample...
FileOutputStream out = new FileOutputStream("/temp/sxssf.xlsx");
sxssfWorkbook.write(out);
out.close();
// dispose of temporary files backing this workbook on disk
sxssfWorkbook.dispose();
}
CellStyle style = workbook.createCellStyle(); // workbook is of SXSSF type
byte orange[] = new byte[] { (byte) 248, (byte) 203, (byte) 173 };
byte thick_shade_blue[] = new byte[] { (byte) 142, (byte) 169, (byte) 219 };
byte blue[] = new byte[] { (byte) 180, (byte) 198, (byte) 231 };
((XSSFCellStyle) style).setFillForegroundColor(new XSSFColor(thick_shade_blue, null));
style.setFillPattern(FillPatternType.SOLID_FOREGROUND);
So, after a bit of searching through the web and reading the docs, i got a hint that SXSSF is actually a wrapper around XSSF, so i typecasted the CellStyle returned by SXSSF workbook to XSSF and was able to use XSSFColor directly for generating colors.
SXSSFWorkbook workbook = new SXSSFWorkbook(50);
Sheet sheet = workbook.createSheet("Image Data");
....
Cell cell = row.createCell(j);
cell.setCellValue(j);
XSSFCellStyle cs1 = (XSSFCellStyle) workbook.createCellStyle();
cs1.setFillForegroundColor(new XSSFColor(new java.awt.Color(red,green,blue)));
cs1.setFillPattern(CellStyle.SOLID_FOREGROUND);
cell.setCellStyle(cs1);