Question

我有一个包含数据的工作表，我正在尝试使用报表过滤器创建一个数据透视表。我想将默认值设置为报表过滤器。

>>> num = []
>>> k = []
>>> for i, j in zip(row[0], row[1]):
     k.append(i or j)


>>> num.append(tuple(k))
>>> num
[(1, 1, 1)]
>>>

列包含0＆1和＃1，我想在报告过滤器中将0设置为默认值。

Answer 1

首先，这个问题在现在被问到的一般情况下是无法回答的。到目前为止，使用apache poi创建数据透视表是处于测试状态。所以我们不仅需要高级apache poi API，还需要底层的低级对象。我们需要确切知道数据透视表中应包含哪种数据。为了能够像Excel那样从所有类型的数据创建数据透视表，需要付出更多的努力。几十年来，微软已经与大型程序员团队进行了编程。从这个apache poi很远。

直到现在，如果数据范围中存在行，则apache poi会添加“default”（<item t="default"/>）类型的数据透视字段项，前提是用作轴字段的数据透视字段。这是因为他们不想查看数据，因此他们假设与数据中的行具有尽可能多的不同值。

这很好，因为Excel会在打开时重建其数据透视缓存。但是如果我们想要预选项目，那就不行了。然后我们必须知道哪些项目可以预先选择。

因此，我们需要至少与预选一样多的项目作为编号项目：<item x="0"/><item x="1"/><item x="2"/> ...

我们需要构建一个缓存定义，它具有这些项的共享元素。

示例：

import org.apache.poi.xssf.usermodel.*;
import org.apache.poi.ss.usermodel.*;
import org.apache.poi.ss.util.*;

import java.util.Random;
import java.io.*;

class PivotTableTest4 {

 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("Value1");
  cell = row.createCell(2);
  cell.setCellValue("Value2");
  cell = row.createCell(3);
  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(r * new java.util.Random().nextDouble());
   cell = row.createCell(2);
   cell.setCellValue(r * new java.util.Random().nextDouble());
   cell = row.createCell(3);
   cell.setCellValue("City " + ((r-1) % 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("D15")), new CellReference("H5"));
   //Configure the pivot table
   //Use first column as row label
   pivotTable.addRowLabel(0);
   //Sum up the second column
   pivotTable.addColumnLabel(DataConsolidateFunction.SUM, 1);
   //Avarage the third column
   pivotTable.addColumnLabel(DataConsolidateFunction.AVERAGE, 2);
   //Add fourth column as page filter
   pivotTable.addReportFilter(3);
/*   
   Apache poi adds 15 pivot field items of type "default" (<item t="default"/>) here. 
   This is because there are 15 rows (A1:D15) and, because they don't have a look at the data, 
   they are assuming max 15 different values. This is fine because Excel will rebuild its pivot cache while opening. 

   But if we want preselect items, then this is not fine. Then we must know what items there are that can be preselected.

   So we need at least as much items as we want preselecting as numbered items: <item x="0"/><item x="1"/><item x="2"/>... 

   And we must build a cache definition which has shared elements for those items.
*/
   for (int i = 0; i < 3; i++) {
    //take the first 3 items as numbered items: <item x="0"/><item x="1"/><item x="2"/>
    pivotTable.getCTPivotTableDefinition().getPivotFields().getPivotFieldArray(3).getItems().getItemArray(i).unsetT();
    pivotTable.getCTPivotTableDefinition().getPivotFields().getPivotFieldArray(3).getItems().getItemArray(i).setX((long)i);
    //build a cache definition which has shared elements for those items 
    //<sharedItems><s v="City 1"/><s v="City 2"/><s v="City 3"/></sharedItems>
    pivotTable.getPivotCacheDefinition().getCTPivotCacheDefinition().getCacheFields().getCacheFieldArray(3).getSharedItems().addNewS().setV("City " + (i+1));
   }

   //Now we can predefinite a page filter. Second item, which is "City 2", in this case.
   pivotTable.getCTPivotTableDefinition().getPageFields().getPageFieldArray(0).setItem(1);

   FileOutputStream fileOut = new FileOutputStream("PivotTableTest4.xlsx");
   wb.write(fileOut);
   fileOut.close();
   wb.close();
  } catch (FileNotFoundException e) {
    e.printStackTrace();
  } catch (IOException e) {
    e.printStackTrace();
  }
 }
}

这需要FAQ中提到的所有模式ooxml-schemas-1.3.jar的完整jar。

如何在Apache POI数据透视表报表过滤器中设置默认值

1 个答案: