bug 60153: move flushSheets out to its own method

git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@1761668 13f79535-47bb-0310-9956-ffa450edef68

src/ooxml/java/org/apache/poi/xssf/streaming/SXSSFWorkbook.java

@@ -907,7 +907,9 @@ public class SXSSFWorkbook implements Workbook {
             try {
                 sheet.getSheetDataWriter().close();
             } catch (IOException e) {
-                // ignore exception here
+                logger.log(POILogger.WARN,
+                        "An exception occurred while closing sheet data writer for sheet "
+                        + sheet.getSheetName() + ".", e);
             }
         }
 
@@ -926,10 +928,7 @@ public class SXSSFWorkbook implements Workbook {
     @Override
     public void write(OutputStream stream) throws IOException
     {
-    	for (SXSSFSheet sheet : _xFromSxHash.values())
+        flushSheets();
-    	{
-    		sheet.flushRows();
-    	}
 
         //Save the template
         File tmplFile = TempFile.createTempFile("poi-sxssf-template", ".xlsx");
@@ -956,6 +955,13 @@ public class SXSSFWorkbook implements Workbook {
         }
     }
     
+    protected void flushSheets() throws IOException {
+        for (SXSSFSheet sheet : _xFromSxHash.values())
+        {
+            sheet.flushRows();
+        }
+    }
+    
     /**
      * Dispose of temporary files backing this workbook on disk.
      * Calling this method will render the workbook unusable.