如何在更多Apache POI Pivot之间共享Pivot缓存？

Question

I have problems when I try to open my Apache POI excel file which consists on a big amount of data (600.000 / 700000 lines) that feeds three pivots generated in three different sheets (using streaming SXSSFWorkbook).

When I try to open the created Excel di MSExcel, this message comes out: "excel can not complete this activity with the available Excel resources ... try to close something ...". So, to save resources, I tried to share the cache between the first two pivots: OK! It's better! But when I try to share the cache even with the third one, MSExcel gives me errors and tries to restore but with wrong results.

Any solution to share cache with more than two pivots with the same data source? Or am I doing something wrong?

Here is the code:

XSSFWorkbook wb = new XSSFWorkbook();
XSSFPivotTable firstPivot = preparefirstPivot(...);
XSSFPivotTable secondPivot = preparesecondPivot(...);
XSSFPivotTable thirdPivot = preparethirdPivot(...);

/* START: shared cache */
/* I remove from workbook all PivotCaches except the firstPivot one */
long firstPivotCacheId = firstPivot.getCTPivotTableDefinition().getCacheId();
List<CTPivotCache> ctPivotCacheList = wb.getCTWorkbook().getPivotCaches().getPivotCacheList();
for (int i = 0; i < ctPivotCacheList.size(); i++) {
    CTPivotCache ctPivotCache = ctPivotCacheList.get(i);
    if(ctPivotCache.getCacheId() != firstPivotChaceId ) {
        wb.getCTWorkbook().getPivotCaches().removePivotCache(i);
    }
}
/* I share the firstPivot cache with the other pivots */
/* work! OK! */
secondPivot.getCTPivotTableDefinition().setCacheId(firstPivotCacheId);
secondPivot.setPivotCache(firstPivot.getPivotCache());
/* here does not work! why?!??!! */
thirdPivot.getCTPivotTableDefinition().setCacheId(firstPivotCacheId);
thirdPivot.setPivotCache(firstPivot.getPivotCache());

Something wrong? Thank you very much!!!

Answer 1

Solved:

XSSFWorkbook wb = new XSSFWorkbook();
XSSFPivotTable firstPivot = preparefirstPivot(...);
XSSFPivotTable secondPivot = preparesecondPivot(...);
XSSFPivotTable thirdPivot = preparethirdPivot(...);

/* START: shared cache */
                List<CTPivotCache> ctPivotCacheList = wb.getCTWorkbook().getPivotCaches().getPivotCacheList();
                if (ctPivotCacheList != null && ctPivotCacheList.size() > 1) {
                    /* useful only with more than one PivotCache */
                    List<Long> ctPivotCacheIdList = new ArrayList<Long>();
                    for (int i = 0; i < ctPivotCacheList.size(); i++) {
                        CTPivotCache ctPivotCache = ctPivotCacheList.get(i);
                        ctPivotCacheIdList.add(new Long(ctPivotCache.getCacheId()));
                    }

                    long firstPivotCacheId = firstPivot.getCTPivotTableDefinition().getCacheId();
                    for (int i = ctPivotCacheIdList.size() - 1; i >= 0; i--) {
                        if (ctPivotCacheIdList.get(i) != firstPivotCacheId) {
                            ctPivotCacheList.remove(i);
                        }
                    }

                    secondPivot.getCTPivotTableDefinition().setCacheId(firstPivotCacheId);
                    secondPivot.setPivotCache(firstPivot.getPivotCache());
                    thirdPivot.getCTPivotTableDefinition().setCacheId(firstPivotCacheId);
                    thirdPivot.setPivotCache(firstPivot.getPivotCache());
}

Thank you all