Develop Reference

Issue while writing cells in excel file using apache POI

I am facing issue while writing the data to excel file.
I am using apache POI 4.1.2 version library.
Below is the sample code.
try {
outputStream = new FileOutputStream(EXCEL_FILE_PATH);
} catch (Exception e) {
System.out.println("Exception While writing excel file " + e.getMessage());
}
Workbook workbook = new HSSFWorkbook();
Sheet sheet = workbook.createSheet("FileCompare");
Row row = sheet.createRow(0);
Cell cellfilename = row.createCell(0);
cellfilename.setCellValue("File Name");
Cell cellfilename1 = row.createCell(1);
cellfilename1.setCellValue("Difference in File 1");
Cell cellfilenam2 = row.createCell(2);
cellfilenam2.setCellValue("Difference in File 2");
for (int diffcol = 1; diffcol < 3; diffcol++) {
for (int i = 1; i < 57; i++) {
Row rows = sheet.createRow(i);
// System.out.println("Difference Coln number " + diffcol);
Cell diffcell = rows.createCell(diffcol);
diffcell.setCellValue("abacds");
/*
* Cell diffcell2 = row.createCell(2); diffcell2.setCellValue("abacds");
*/
}
}
try {
workbook.write(outputStream);
} catch (Exception e) {
e.printStackTrace();
} finally {
outputStream.flush();
outputStream.close();
workbook.close();
}
In this only last column cells is getting saved in excel file , previous cells are kept as blank.
Kindly help and let me know if I am doing something wrong?

Not sure about the actual api but I think you inner loop should create columns and your outer one should create rows like this
for (int row=1:row<57;row++)
{
Row rows = sheet.createRow(row);
for (int diffCol = 1; diffCol < 3; difCol++)
{
Cell diffcell = rows.createCell(diffcol);
diffcell.setCellValue("abacds");
}
}

The problem is that inside your loop you're always using sheet.createRow(i) to retrieve the row you need, but as the docs says (docs that are written not so clear, actually) this method is always recreating a brand new & empty row, deleting the existing one (if a row at that i-position was already present).
It means that each iteration of yuor loop is actually deleting previous rows creating brand new rows: at the end only rows created by the last iteration are surviving!
To solve you're problem, use sheet.createRow(i) only one time in order to create the row at i-position and then only use sheet.getRow(i) to retreive it.
So replace (in your code) the following wrong line
Row rows = sheet.createRow(i);
with the following code
Row row = sheet.getRow(i);
if (row == null) row = sheet.createRow(i);
where new row is created only if it does not already exist!
And you're done, it works like a charm!

Apache POI createTable generates corrupted file when a header's cell contains a line break

I am using Apache POI 4.1.2 to create Excel files in Java. I have a piece of code that creates a table from existing cells and everything used to work fine, untill I had a linebreak inside a header's cell.
I tried to change the table's column name afterward but it didn't fix anything.
Below is a minimal piece of code to reproduce the problem:
public void test() throws IOException {
XSSFWorkbook wb = new XSSFWorkbook();
XSSFSheet sheet = wb.createSheet();
// headers
XSSFRow headersRow = sheet.createRow(0);
headersRow.createCell(0).setCellValue("Column1");
headersRow.createCell(1).setCellValue("Column2");
// a second row
XSSFRow row = sheet.createRow(1);
row.createCell(0).setCellValue(1);
row.createCell(1).setCellValue(2);
// create a table
AreaReference area = wb.getCreationHelper().createAreaReference(
new CellReference(sheet.getRow(0).getCell(0)),
new CellReference(sheet.getRow(1).getCell(1))
);
XSSFTable table = sheet.createTable(area);
// styling (no problem here)
sheet.setColumnWidth(0, 5000);
sheet.setColumnWidth(1, 5000);
CTTable cttable = table.getCTTable();
cttable.addNewTableStyleInfo();
XSSFTableStyleInfo style = (XSSFTableStyleInfo) table.getStyle();
style.setName("TableStyleMedium6");
style.setShowColumnStripes(false);
style.setShowRowStripes(true);
cttable.addNewAutoFilter().setRef(area.formatAsString());
CellStyle cellStyle = wb.createCellStyle();
cellStyle.setWrapText(true);
headersRow.getCell(0).setCellStyle(cellStyle);
// this file is OK
try (FileOutputStream outputStream = new FileOutputStream("C:\\tmp\\test.xlsx")) {
wb.write(outputStream);
}
// add a line break in a header's cell
headersRow.getCell(0).setCellValue("Column1\nwith a line break");
// this file has a problem
try (FileOutputStream outputStream = new FileOutputStream("C:\\tmp\\test2.xlsx")) {
wb.write(outputStream);
}
// this doesn't fix anything
table.getColumns().get(0).setName("Column1");
try (FileOutputStream outputStream = new FileOutputStream("C:\\tmp\\test3.xlsx")) {
wb.write(outputStream);
}
// neither does this
cttable.getTableColumns().getTableColumnList().get(0).setName("Column1");
try (FileOutputStream outputStream = new FileOutputStream("C:\\tmp\\test4.xlsx")) {
wb.write(outputStream);
}
}
Excel loads text.xlsx properly, but complains about all other files:
We found a problem with some content...
After Excel fixes the files, everything is OK but I would like to get rid of the warning message.
Any help will be appreciated.
Thanks

This is an inaccuracy with XSSFTable.updateHeaders. This method gets called while the table's XML gets written. This is because the table column names always must be synchronized with the cell contents. For example if the cell content is "Column1" and this cell is a column header of a table, then this tables column name also must be "Column1" (XML: <tableColumn id="1" name="Column1"/>).
But for line feeds in column headers, there is a specialty. If the cell content is "Column1\nwith a line break" and this cell is a column header of a table, then this tables column name must be XML as <tableColumn id="1" name="Column1_x000a_with a line break"/>. So "\n" is replaced by "x000a". Also "\r" would must be replaced by "x000d". This is because "\r\n" line breaks will not have the meaning of line break in XML.
So XSSFTable.java - updateHeaders would must be patched that way that "\n" gets replaced by "x000a" and "\r" gets replaced by "x000d".
...
public void updateHeaders() {
XSSFSheet sheet = (XSSFSheet)getParent();
CellReference ref = getStartCellReference();
if (ref == null) return;
int headerRow = ref.getRow();
int firstHeaderColumn = ref.getCol();
XSSFRow row = sheet.getRow(headerRow);
DataFormatter formatter = new DataFormatter();
if (row != null && row.getCTRow().validate()) {
int cellnum = firstHeaderColumn;
CTTableColumns ctTableColumns = getCTTable().getTableColumns();
if(ctTableColumns != null) {
for (CTTableColumn col : ctTableColumns.getTableColumnList()) {
XSSFCell cell = row.getCell(cellnum);
if (cell != null) {
String colName = formatter.formatCellValue(cell);
colName = colName.replace("\n", "_x000a_");
colName = colName.replace("\r", "_x000d_");
col.setName(colName);
}
cellnum++;
}
}
}
tableColumns = null;
columnMap = null;
xmlColumnPrs = null;
commonXPath = null;
}
...
Since XSSFTable.updateHeaders gets called while the table's XML gets written while XSSFWorkbook.write, there is no other way than patching this method. One does not have any chance to change table's XML while XSSFWorkbook.write.

Apache POI Pivot table error when same index is used for both column and row label

I am trying to create a pivot table to do cohort analysis
pivotTable.addColumnLabel(DataConsolidateFunction.COUNT, 1);
pivotTable.addRowLabel(1);
this is giving me an error while opening the file that the file is corrupt do you want to still open the file, when I say yes and open it, the result looks fine, the only issue is the error.
I did a workaround to have a duplicate column data with different name
for ex:
say column 1 is email added a duplicate column 36 with name dup email and did as shown below, it works fine
pivotTable.addColumnLabel(DataConsolidateFunction.COUNT, 1);
pivotTable.addRowLabel(35);
why in the first place it failed when I give both column and row label as 1.
Any help is greatly appreciated

If you set pivotTable.addRowLabel(1) using apache poi, then apache poi sets pivot field 1 only to be axisRow but it needs to be dataField too if you also want to pivotTable.addColumnLabel(DataConsolidateFunction.COUNT, 1). So we neeed to correct this.
Example:
import org.apache.poi.xssf.usermodel.*;
import org.apache.poi.ss.usermodel.*;
import org.apache.poi.ss.util.*;
import java.io.*;
class PivotTableTest5 {
private static void setCellData(Sheet sheet) {
Row row = sheet.createRow(0);
Cell cell = row.createCell(0);
cell.setCellValue("Name");
cell = row.createCell(1);
cell.setCellValue("City");
for (int r = 1; r < 15; r++) {
row = sheet.createRow(r);
cell = row.createCell(0);
cell.setCellValue("Name " + ((r-1) % 4 + 1));
cell = row.createCell(1);
cell.setCellValue("City " + (int)((new java.util.Random().nextDouble() * 3)+1) );
}
}
public static void main(String[] args) {
try {
XSSFWorkbook wb = new XSSFWorkbook();
XSSFSheet sheet = wb.createSheet();
//Create some data to build the pivot table on
setCellData(sheet);
XSSFPivotTable pivotTable = sheet.createPivotTable(
new AreaReference(new CellReference("A1"), new CellReference("B15")), new CellReference("H5"));
//Count the second column. This needs to be second column a data field.
pivotTable.addColumnLabel(DataConsolidateFunction.COUNT, 1);
//Use second column as row label
pivotTable.addRowLabel(1);
//Apache poi sets pivot field 1 (second column) only to be axisRow but it needs to be dataField too.
pivotTable.getCTPivotTableDefinition().getPivotFields().getPivotFieldArray(1).setDataField(true);
FileOutputStream fileOut = new FileOutputStream("PivotTableTest5.xlsx");
wb.write(fileOut);
fileOut.close();
wb.close();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
}

poi cannot write data into .xlsx

the problem is when I tried to write data into cells, the cell either hasn't been created or it just doesn't show the data in it.
For instance,
Row[] rownames = new Row[names.size()];
for(int i = 0; i < names.size(); i++){
rownames[i] = sheet.createRow(i+3);
Cell machine = rownames[i].createCell(0);
machine.setCellType(Cell.CELL_TYPE_STRING);
machine.setCellValue(names.get(i).toString());
}
names[] is an array that contains a list of names.
Cell machine = rownames[i].createCell(0); creates a cell at (i+3,0), in which i means row.
machine.setCellValue(names.get(i).toString()); sets cell value to the corresponding name[i].
I tried print names[] and machine.getStringCellValue(), and both of them can return the exact correct data (like output to console). but there's nothing in xlsx file. many thanks in advance.
EDIT:
Let me explain more clearly, so if everything goes well, the very part of this xlsx file should be like this:
harry | (row 3, col 0)
kate | (row 4, col 0)
jim | (row 5, col 0)
aaron | (row 6, col 0)
...
...
But now the situation is:
| (row 3, col 0)
| (row 4, col 0)
| (row 5, col 0)
| (row 6, col 0)
...
...
Right now the xlsx is 4KB. it contains some other information, which have been put there via this very program. Those parts don't have this problem.

Looks like you create row by same index multiple times in further (non posted) code.
How poi creates XSSFRow:
public XSSFRow createRow(int rownum) {
CTRow ctRow;
XSSFRow prev = _rows.get(rownum);
if(prev != null){
// the Cells in an existing row are invalidated on-purpose, in order to clean up correctly, we
// need to call the remove, so things like ArrayFormulas and CalculationChain updates are done
// correctly.
// We remove the cell this way as the internal cell-list is changed by the remove call and
// thus would cause ConcurrentModificationException otherwise
while(prev.getFirstCellNum() != -1) {
prev.removeCell(prev.getCell(prev.getFirstCellNum()));
}
ctRow = prev.getCTRow();
ctRow.set(CTRow.Factory.newInstance());
}
...
}
So, if row exists and contains cell, all cells with data will be removed.
To avoid this, use CellUtil class:
Get a row from the spreadsheet, and create it if it doesn't exist.
CellUtil.getRow(rowIndex, sheet);
Get a specific cell from a row. If the cell doesn't exist, then create it.
CellUtil.getCell(row, columnIndex);

You have not posted file opening and closing code. Based on description, it seems that you are not writing data back to Excel file. Do something like this:
FileOutputStream out = new FileOutputStream(new File("path of excel file"));
wb.write(out);
wb.close();
out.close();
After executing entire code, then check excel file for the output generated.

import org.apache.poi.hssf.usermodel.HSSFFont;
import org.apache.poi.hssf.usermodel.HSSFRow;
import org.apache.poi.hssf.usermodel.HSSFSheet;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
This is my code...
HSSFFont boldFont;
HSSFFont bodyFont;
HSSFWorkbook workbook = new HSSFWorkbook();
HSSFSheet sheet = workbook.createSheet("namefile");
HSSFRow row = sheet.createRow((short)0);
//HSSFCellStyle cellStyle = workbook.createCellStyle();
//cellStyle.setFillBackgroundColor(HSSFColor.GREY_25_PERCENT.index);
//cellStyle.setFillForegroundColor(HSSFColor.LAVENDER.index);
//cellStyle.setFillPattern(HSSFCellStyle.ALIGN_CENTER);
row.setHeightInPoints(23);
sheet.setColumnWidth((short)0, (short)2000);
sheet.setColumnWidth((short)1, (short)3000);
sheet.setColumnWidth((short)2, (short)3000);
sheet.setColumnWidth((short)3, (short)3000);
sheet.setColumnWidth((short)4, (short)3000);
sheet.setColumnWidth((short)5, (short)3000);
sheet.setColumnWidth((short)6, (short)3000);
sheet.setColumnWidth((short)7, (short)3000);
sheet.setColumnWidth((short)8, (short)3000);
sheet.setColumnWidth((short)9, (short)3000);
sheet.setColumnWidth((short)10, (short)3000);
sheet.setColumnWidth((short)11, (short)3000);
row.createCell((short)0).setCellValue("FLT NO");
row.createCell((short)1).setCellValue("LEG");
row.createCell((short)2).setCellValue("DATE");
row.createCell((short)3).setCellValue("AC-REG");
row.createCell((short)4).setCellValue("SCHED DEP");
row.createCell((short)5).setCellValue("OFFBLK");
row.createCell((short)6).setCellValue("AIRBORNE");
row.createCell((short)7).setCellValue("LANDING");
row.createCell((short)8).setCellValue("ONBLK");
row.createCell((short)9).setCellValue("SCHED ARR");
row.createCell((short)10).setCellValue("FUEL_USED_PILOT");
row.createCell((short)11).setCellValue("ACTUAL FUEL");
ProofSheetFPRModel model = new ProofSheetFPRModel();
int rownum = 1;
for (int i=0; i<DataList.size(); i++)
{
model = DataList.get(i);
row = sheet.createRow((short)rownum);
row.createCell((short)0).setCellValue(model.getFlightNo());
row.createCell((short)1).setCellValue(model.getLEG());
row.createCell((short)2).setCellValue(model.getDate());
row.createCell((short)3).setCellValue(model.getAC_REG());
row.createCell((short)4).setCellValue(model.getSCHED_DEP());
row.createCell((short)5).setCellValue(model.getOFF_BLK());
row.createCell((short)6).setCellValue(model.getAIRBORNE());
row.createCell((short)7).setCellValue(model.getLANDG());
row.createCell((short)8).setCellValue(model.getON_BLK());
row.createCell((short)9).setCellValue(model.getSCHED_ARR());
row.createCell((short)10).setCellValue(model.getFUEL_USED_PILOT());
row.createCell((short)11).setCellValue(model.getACTUAL_FUEL());
rownum++;
}
try
{
FileOutputStream out = new FileOutputStream(new File(filePath));
workbook.write(out);
out.close();
}
catch (FileNotFoundException e)
{
e.printStackTrace();
}
catch (IOException e)
{
e.printStackTrace();
}

java program to read specific data

I need java code to read data for specific column from excel sheet. – (lo number, line, voucher no, stloc , quantity ,activity.)
These set of values for a particular column will be used for sql query (jdbc-odbc connection done).
The output for the query will be matched with a column in this sheet (this part ll be done later)
Kindly help.
sample excel sheet

/*
* To change this template, choose Tools | Templates
* and open the template in the editor.
*/
package excelfilereading;
/**
*
* #author vkantiya
*/
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.hssf.usermodel.HSSFSheet;
import org.apache.poi.hssf.usermodel.HSSFRow;
import org.apache.poi.hssf.usermodel.HSSFCell;
import java.io.FileInputStream;
import java.io.IOException;
import java.util.Iterator;
import java.util.List;
import java.util.ArrayList;
public class Main {
#SuppressWarnings("unchecked")
public static void main(String[] args) throws Exception {
//
// An excel file name. You can create a file name with a full
// path information.
//
String filename = "FirstExcel.xls";
// Create an ArrayList to store the data read from excel sheet.
//
List sheetData = new ArrayList();
FileInputStream fis = null;
try {
//
// Create a FileInputStream that will be use to read the
// excel file.
//
fis = new FileInputStream(filename);
//
// Create an excel workbook from the file system.
//
HSSFWorkbook workbook = new HSSFWorkbook(fis);
//
// Get the first sheet on the workbook.
//
HSSFSheet sheet = workbook.getSheetAt(0);
//
// When we have a sheet object in hand we can iterator on
// each sheet's rows and on each row's cells. We store the
// data read on an ArrayList so that we can printed the
// content of the excel to the console.
//
Iterator rows = sheet.rowIterator();
while (rows.hasNext()) {
HSSFRow row = (HSSFRow) rows.next();
Iterator cells = row.cellIterator();
List data = new ArrayList();
while (cells.hasNext()) {
HSSFCell cell = (HSSFCell) cells.next();
data.add(cell);
}
sheetData.add(data);
}
} catch (IOException e) {
e.printStackTrace();
} finally {
if (fis != null) {
fis.close();
}
}
showExelData(sheetData);
}
private static void showExelData(List sheetData) {
//
// Iterates the data and print it out to the console.
//
for (int i = 0; i < sheetData.size(); i++) {
List list = (List) sheetData.get(i);
for (int j = 0; j < list.size(); j++) {
HSSFCell cell = (HSSFCell) list.get(j);
System.out.print(
cell.getRichStringCellValue().getString());
if (j < list.size() - 1) {
System.out.print(", ");
}
}
System.out.println("");
}
}
}

Have a look at Apache POI - the Java API for Microsoft Documents.
It covers
Excel (SS=HSSF+XSSF)
Word (HWPF+XWPF)
PowerPoint (HSLF+XSLF)
OpenXML4J (OOXML)
OLE2 Filesystem (POIFS)
OLE2 Document Props (HPSF)
Outlook (HSMF)
Visio (HDGF) TNEF (HMEF)
Publisher (HPBF)