java - XSSF(Apache POI)-从数据透视表中的单列值添加多列标签

我目前正在使用Apache POI 3.12添加数据透视表。这是我的sample.xlsx文件：



现在，我使用以下代码为上述数据创建数据透视表。

    File excel = new File("sample.xlsx");
    FileInputStream fis = new FileInputStream(excel);
    XSSFWorkbook wb = new XSSFWorkbook(fis);
    XSSFSheet sheet = wb.getSheetAt(0);
    XSSFPivotTable pivotTable = sheet.createPivotTable(new AreaReference("A3:C7"), new CellReference("E3"));
    pivotTable.addRowLabel(0);
    pivotTable.addColumnLabel(DataConsolidateFunction.SUM, 1);
    pivotTable.addDataColumn(1, true);
    pivotTable.addReportFilter(2);
    FileOutputStream fileOut = new FileOutputStream("output.xlsx");
    wb.write(fileOut);
    fileOut.close();
    wb.close();

我的output.xlsx文件具有以下数据透视表：



当我要在excel中编辑数据透视表时，会在页面字段而非列字段中添加year列。实际上，我需要以下结果：



我无法从单列值添加多列标签。请你帮助我好吗？提前致谢

最佳答案

类XSSFPivotTable处于@Beta状态。因此，只有使用底层的低级对象才有可能。

XSSFWorkbook wb = new XSSFWorkbook(new FileInputStream("sample.xlsx"));
XSSFSheet sheet = wb.getSheetAt(0);

//the following creates a Pivot Table with 3 PivotFields (0 to 2) (3 Columns A3:C7); all dataField="false" at first
XSSFPivotTable pivotTable = sheet.createPivotTable(new AreaReference(new CellReference("A3"), new CellReference("C7")), new CellReference("E3"));

//the following makes PivotFields(0) an Axis-Field AXIS_ROW with 5 Items (5 Rows A3:C7). Why one Item for each row? I don't know.
//and it adds a new RowField for this
pivotTable.addRowLabel(0);

//the following makes PivotFields(1) a DataField and creates a DataColumn for this
pivotTable.addColumnLabel(DataConsolidateFunction.SUM, 1);
//pivotTable.addDataColumn(2, false); //not neccessary since addColumnLabel already adds a DataColumn

//now PivotFields(2) needs to be an Axis-Field AXIS_COL
pivotTable.getCTPivotTableDefinition().getPivotFields().getPivotFieldArray(2).setAxis(
  org.openxmlformats.schemas.spreadsheetml.x2006.main.STAxis.AXIS_COL);

//PivotFields(2) needs to have at least one Item
pivotTable.getCTPivotTableDefinition().getPivotFields().getPivotFieldArray(2).addNewItems();
pivotTable.getCTPivotTableDefinition().getPivotFields().getPivotFieldArray(2).getItems().addNewItem().setT(
  org.openxmlformats.schemas.spreadsheetml.x2006.main.STItemType.DEFAULT);

//new ColField needs to be added
pivotTable.getCTPivotTableDefinition().addNewColFields().addNewField().setX(2);

//pivotTable.addReportFilter(2);
FileOutputStream fileOut = new FileOutputStream("output.xlsx");
wb.write(fileOut);
fileOut.close();
wb.close();

不需要pivotTable.addDataColumn(1, true);，因为addColumnLabel已经添加了DataColumn。