數(shù)據(jù)透視表定義中有一個(gè)元素，如果有多個(gè)數(shù)據(jù)字段作為列字段，colFields則至少需要一個(gè)元素。field但apache poi如果僅設(shè)置一個(gè)列標(biāo)簽，則不會(huì)添加該字段，因?yàn)槿绻麅H存在一個(gè)列字段，則不需要該字段。
但由于您低級(jí)別添加了一個(gè)數(shù)據(jù)字段作為列字段，因此它缺少該 colFields字段。這就是為什么在打開文件時(shí)出錯(cuò)的原因Excel。
如果設(shè)置了多個(gè)列標(biāo)簽，則apache poi添加該colFields字段。這就是它起作用的原因。
因此，在低級(jí)別創(chuàng)建數(shù)據(jù)字段后，將以下內(nèi)容添加到您的代碼中：
...
// at least one field in colFields is needed if there are multiple data fields
CTColFields colFields;
if(pivotTable.getCTPivotTableDefinition().getColFields() != null) {
colFields = pivotTable.getCTPivotTableDefinition().getColFields();
} else {
colFields = pivotTable.getCTPivotTableDefinition().addNewColFields();
}
CTField field;
if (colFields.getFieldList().size() == 0) {
field = colFields.addNewField();
field.setX(-2);
}
...
這將添加一個(gè)新colFields元素（如果尚不存在）。它會(huì)field在那里添加該元素（如果尚未存在）。
再次完整的例子：
import java.io.FileOutputStream;
import org.apache.poi.ss.SpreadsheetVersion;
import org.apache.poi.ss.usermodel.*;
import org.apache.poi.ss.util.*;
import org.apache.poi.xssf.usermodel.*;
import org.openxmlformats.schemas.spreadsheetml.x2006.main.*;
class CreatePivotTableCalculatedFields {
public static void main(String[] args) throws Exception {
createPivotTable();
}
private static void createPivotTable() throws Exception {
try (XSSFWorkbook wb = new XSSFWorkbook();
FileOutputStream fileOut = new FileOutputStream("Output.xlsx")) {
XSSFSheet dataSheet = wb.createSheet("1econtent");
XSSFSheet pivotSheet = wb.createSheet("1e");
setCellData(dataSheet, wb);
AreaReference source = new AreaReference("A1:F5", SpreadsheetVersion.EXCEL2007);
CellReference position = new CellReference(0,0);
XSSFPivotTable pivotTable = pivotSheet.createPivotTable(source, position,wb.getSheet("1econtent"));
pivotTable.addRowLabel(2);
pivotTable.addRowLabel(0);
pivotTable.addColumnLabel(DataConsolidateFunction.SUM, 3);
pivotSheet.setDisplayGridlines(false);
wb.setSelectedTab(1);
wb.setActiveSheet(1);
// customize pivot table
CTCacheFields ctCacheFields = pivotTable.getPivotCacheDefinition().getCTPivotCacheDefinition().getCacheFields();
CTCacheField ctCacheField = ctCacheFields.addNewCacheField();
ctCacheField.setName("Field");
ctCacheField.setFormula("'Actuals' / 'Estimates'");
ctCacheField.setDatabaseField(false);
ctCacheFields.setCount(ctCacheFields.sizeOfCacheFieldArray());
CTPivotField pivotField = pivotTable.getCTPivotTableDefinition().getPivotFields().addNewPivotField();
pivotField.setDataField(true);
pivotField.setDragToCol(false);
pivotField.setDragToPage(false);
pivotField.setDragToRow(false);
pivotField.setShowAll(false);
pivotField.setDefaultSubtotal(false);
CTDataFields dataFields;
if(pivotTable.getCTPivotTableDefinition().getDataFields() != null) {
dataFields = pivotTable.getCTPivotTableDefinition().getDataFields();
} else {
dataFields = pivotTable.getCTPivotTableDefinition().addNewDataFields();
}
CTDataField dataField = dataFields.addNewDataField();
dataField.setName("Calculated Field");
dataField.setFld(pivotTable.getPivotCacheDefinition().getCTPivotCacheDefinition().getCacheFields().getCount()-1);
dataField.setBaseItem(0);
dataField.setBaseField(0);
DataFormat dataformat = pivotTable.getParentSheet().getWorkbook().createDataFormat();
short numFmtId = dataformat.getFormat("0.0%");
dataField.setNumFmtId(numFmtId);
// at least one field in colFields is needed if there are multiple data fields
CTColFields colFields;
if(pivotTable.getCTPivotTableDefinition().getColFields() != null) {
colFields = pivotTable.getCTPivotTableDefinition().getColFields();
} else {
colFields = pivotTable.getCTPivotTableDefinition().addNewColFields();
}
CTField field;
if (colFields.getFieldList().size() == 0) {
field = colFields.addNewField();
field.setX(-2);
}
wb.write(fileOut);
}
}
public static void setCellData(XSSFSheet sheet, XSSFWorkbook wb){
Object[][] data = new Object[][] {
new Object[] {"Names", "Age", "Dept", "Salary", "Actuals", "Estimates"},
new Object[] {"Adam", 22d, "Sales", 10d, 12d, 60d},
new Object[] {"Bran", 24d, "Finance", 20d, 24d, 60d},
new Object[] {"Jane", 23d, "IT", 30d, 30d, 60d},
new Object[] {"Dave", 30d, "Sales", 50d, 6d, 60d}
};
XSSFRow row;
XSSFCell cell;
for (int r = 0; r < data.length; r++) {
row = sheet.createRow(r);
for (int c = 0 ; c < data[r].length; c++) {
cell = row.createCell(c);
if (data[r][c] instanceof String) {
cell.setCellValue((String)data[r][c]);
} else if (data[r][c] instanceof Double) {
cell.setCellValue((Double)data[r][c]);
}
}
}
}
}
