如何使用另一个工作簿作为数据源创建 Apache POI Pivot？

Question

如何使用另一个工作簿作为数据源来创建 Apache POI Pivot？ AreaReference 不接受工作簿作为参数，而只接受 sheetName。

/** Data source sheet */
XSSFWorkbook wb = new XSSFWorkbook();
XSSFSheet dataSourceSheet = wb.createSheet("dataSourceSheet");

CellReference position = new CellReference(0, 0, true, true);
AreaReference source = new AreaReference(
                       new CellReference("dataSourceSheet", 0, 0, true, true),
                       new CellReference("dataSourceSheet", 100, 100, true, true),
                       null);
            
/** Pivot */
XSSFWorkbook wbPivot = new XSSFWorkbook();
XSSFSheet pivotSheet = wbPivot.createSheet("myPivot");
XSSFPivotTable pivotTable = pivotSheet.createPivotTable(source, position); /* ???? */

Answer 1

到目前为止，这不是apache poi 提供的任何东西。如果知道Excel 在这种情况下存储了什么，就可以做到。

创建数据透视表的主要原理是相同的。不同之处在于数据透视缓存的工作表源附加包含一个rId，它指的是与源工作簿的外部关系。因此，额外的任务是创建与源工作簿的外部关系，并将 rId 设置为数据透视缓存的工作表源。

以下代码显示了如何做到这一点：

import java.io.File;
import java.io.FileOutputStream;
import java.io.FileInputStream;

import org.apache.poi.ss.SpreadsheetVersion;
import org.apache.poi.ss.util.AreaReference;
import org.apache.poi.ss.util.CellReference;
import org.apache.poi.ss.usermodel.DataConsolidateFunction;
import org.apache.poi.openxml4j.opc.TargetMode;
import org.apache.poi.xssf.usermodel.*;

class CreatePivotTable {

 public static void main(String[] args) throws Exception {

  String[] headers = new String[] { "Company", "Status", "Counter" };
  Object[][] sheetData = {
   {"Company 1", "OK", "x"},
   {"Company 1", "NOK", "x"},
   {"Company 2", "NOK", "x"},
   {"Company 1", "OK", "x"},
   {"Company 3", "OK", "x"},
   {"Company 1", "NOK", "x"},
  };

  //File sourceWorkbookFile = new File("C:/Users/axelr/Documents/PivotData.xlsx");
  //File pivotWorkbookFile = new File("C:/Users/axelr/Documents/PivotTable.xlsx");
  File sourceWorkbookFile = new File("PivotData.xlsx");
  File pivotWorkbookFile = new File("PivotTable.xlsx");
  
  // creating source workbook  
  try (XSSFWorkbook workbook = new XSSFWorkbook(); 
       FileOutputStream fileout = new FileOutputStream(sourceWorkbookFile) ) {

   XSSFSheet dataSheet = workbook.createSheet("Data");
   XSSFRow row;
   XSSFCell cell;
   int r = 0;
   row = dataSheet.createRow(r++);
   int c = 0;
   for (String header : headers) {
    cell = row.createCell(c++);
    cell.setCellValue(header);
   }
   for (Object[] dataRow : sheetData) {
    row = dataSheet.createRow(r++);
    c = 0;
    for (Object value : dataRow) {
     cell = row.createCell(c++);
     if (value instanceof String) {
      cell.setCellValue((String)value);
     } //else if...
    }
   } 
   workbook.write(fileout);
  }
  
  // creating pivot workbook  
  try (XSSFWorkbook sourceWorkbook = new XSSFWorkbook(new FileInputStream(sourceWorkbookFile));
       XSSFWorkbook pivotWorkbook = new XSSFWorkbook(); 
       FileOutputStream fileout = new FileOutputStream(pivotWorkbookFile) ) {
           
   XSSFSheet dataSheet = sourceWorkbook.getSheet("Data");
   XSSFSheet pivotSheet = pivotWorkbook.createSheet("Pivot");

   AreaReference areaReference = new AreaReference(
    new CellReference(0, 0),
    new CellReference(dataSheet.getLastRowNum(), dataSheet.getRow(0).getLastCellNum()-1),
    SpreadsheetVersion.EXCEL2007);

   XSSFPivotTable pivotTable = pivotSheet.createPivotTable(areaReference, new CellReference("A4"), dataSheet);
   
   XSSFPivotCacheDefinition pivotCacheDefinition = pivotTable.getPivotCacheDefinition();
   String rId =  pivotCacheDefinition.getPackagePart().addRelationship( 
    sourceWorkbookFile.toURI(), 
    TargetMode.EXTERNAL, 
    "http://schemas.openxmlformats.org/officeDocument/2006/relationships/externalLinkPath")
    .getId();
   pivotCacheDefinition.getCTPivotCacheDefinition().getCacheSource().getWorksheetSource().setId(rId); 

   pivotTable.addRowLabel(0);
   pivotTable.addRowLabel(1);
   pivotTable.addColumnLabel(DataConsolidateFunction.COUNT, 2);

   pivotWorkbook.write(fileout);

  }

 }
}

此代码已使用当前apache poi 版本4.1.2 和5.0.0 进行测试和工作。