Hi, I have an instance of SXSSFSheet and when I'm trying to fill it with values concurrently, such exceptions occurs:
java.util.ConcurrentModificationException: null at java.util.TreeMap$PrivateEntryIterator.nextEntry(TreeMap.java:1211) ~[na:1.8.0_152] at java.util.TreeMap$EntryIterator.next(TreeMap.java:1247) ~[na:1.8.0_152] at java.util.TreeMap$EntryIterator.next(TreeMap.java:1242) ~[na:1.8.0_152] at org.apache.poi.xssf.streaming.SXSSFSheet.getRowNum(SXSSFSheet.java:1851) ~[poi-ooxml-3.14.jar:3.14] at org.apache.poi.xssf.streaming.SXSSFRow.getRowNum(SXSSFRow.java:218) ~[poi-ooxml-3.14.jar:3.14] at org.apache.poi.xssf.streaming.SXSSFCell.getRowIndex(SXSSFCell.java:84) ~[poi-ooxml-3.14.jar:3.14] at org.apache.poi.xssf.streaming.SXSSFCell.setHyperlink(SXSSFCell.java:649) ~[poi-ooxml-3.14.jar:3.14] java.lang.NullPointerException: null at org.apache.poi.xssf.streaming.AutoSizeColumnTracker.updateColumnWidths(AutoSizeColumnTracker.java:302) ~[poi-ooxml-3.14.jar:3.14] at org.apache.poi.xssf.streaming.SXSSFSheet.flushOneRow(SXSSFSheet.java:1834) ~[poi-ooxml-3.14.jar:3.14] at org.apache.poi.xssf.streaming.SXSSFSheet.flushRows(SXSSFSheet.java:1813) ~[poi-ooxml-3.14.jar:3.14] at org.apache.poi.xssf.streaming.SXSSFSheet.createRow(SXSSFSheet.java:155) ~[poi-ooxml-3.14.jar:3.14] I put synchronization on the object access and it works fine now, but is not it an issue? Should the SXSSFCell and SXSSFSheet objects be thread safe? Best wishes, Pavel
