Workbook::getSheetName() returning null due to sheet name truncation to 31 characters.

[KrisPatAU]

In 5.x versions, while creating a sheet, it was decided to truncate its name:

String sn = (sheetname.length() > 31) ? sheetname.substring(0, 31) : sheetname;

But as a consequence, trying to get the sheet using the same original name results in null.

import org.apache.poi.ss.usermodel.Workbook;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;

public class ApachePOISheetNameTest {
	private static final String LONG_SHEET_NAME = "ThisSheetNameIsMoreThan31Characters";

	public static void main(String[] args) throws Exception {
		try (Workbook workbook = new HSSFWorkbook()) {
			workbook.createSheet(LONG_SHEET_NAME);
			Sheet sheet = workbook.getSheet(LONG_SHEET_NAME);
			System.out.println(sheet);	// null
			sheet = workbook.getSheet(LONG_SHEET_NAME.substring(0, 31));
			System.out.println(sheet);	// works
		}
	}

}

[Satwik-Bhardwaj]

You are correct. If POI silently truncates the sheet name, it should not return null when attempting to access the sheet using the full name. This behavior indicates an inconsistency. To address this issue, we should throw an exception when trying to get the sheet if the name exceeds 31 characters.