Bug 56957

I can reproduce the problem with your small test file

No idea why it's happening, hopefully someone else can investigate...

The problem is that the original xlsx does not contain a file for the SharedString table in the zip-file and thus an empty string table is created during loading the file initially.

During close(), the file is written back and a 0-byte sharedStrings.xml file is created, which later fails during loading the xlsx again.

I tried it with the following change, which makes this test work, however I am not sure if this is the correct way to exclude parts which do not have any size:

--- a/src/ooxml/java/org/apache/poi/openxml4j/opc/internal/marshallers/ZipPartMarshaller.java
+++ b/src/ooxml/java/org/apache/poi/openxml4j/opc/internal/marshallers/ZipPartMarshaller.java
@@ -63,6 +63,11 @@ public final class ZipPartMarshaller implements PartMarshaller {
                        // Normally should happen only in developement phase, so just throw
                        // exception
                }
+
+               // check if there is anything to save
+               if(part.getSize() == 0) {
+                   return true;
+               }
 
                ZipOutputStream zos = (ZipOutputStream) os;
                ZipEntry partEntry = new ZipEntry(ZipHelper

What xbean version you are using?

I can reproduce the problem in 3.11 version with xmlbeans 2.6.0.

BTW, a possible workaround if you are just reading from the file is to open the file in "read-only" mode, then the problem does not happen:

Workbook workbook = WorkbookFactory.create(OPCPackage.open(file, PackageAccess.READ));

(In reply to Dominik Stadler from comment #5)
> BTW, a possible workaround if you are just reading from the file is to open
> the file in "read-only" mode, then the problem does not happen:
> 
> Workbook workbook = WorkbookFactory.create(OPCPackage.open(file,
> PackageAccess.READ));

I get below exception when I open empty file in read-noly mode:

org.apache.poi.POIXMLException: org.apache.poi.openxml4j.exceptions.InvalidOperationException: Operation not allowed, document open in read only mode!
	at org.apache.poi.POIXMLDocumentPart.createRelationship(POIXMLDocumentPart.java:394)
	at org.apache.poi.POIXMLDocumentPart.createRelationship(POIXMLDocumentPart.java:354)
	at org.apache.poi.xssf.usermodel.XSSFWorkbook.onDocumentRead(XSSFWorkbook.java:341)
	at org.apache.poi.POIXMLDocument.load(POIXMLDocument.java:166)
	at org.apache.poi.xssf.usermodel.XSSFWorkbook.<init>(XSSFWorkbook.java:240)
	at com.X.Y.db.process.SourceProcessorA.process(SourceProcessorA.java:42)
	at com.X.Y.db.process.SourceProcessorATest.testProcessEmptySource(SourceProcessorATest.java:59)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:45)
	at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:15)
	at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:42)
	at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:20)
	at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:263)
	at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:68)
	at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:47)
	at org.junit.runners.ParentRunner$3.run(ParentRunner.java:231)
	at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:60)
	at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:229)
	at org.junit.runners.ParentRunner.access$000(ParentRunner.java:50)
	at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:222)
	at org.junit.runners.ParentRunner.run(ParentRunner.java:300)
	at org.junit.runner.JUnitCore.run(JUnitCore.java:157)
	at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:74)
	at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:211)
	at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:67)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
	at com.intellij.rt.execution.application.AppMain.main(AppMain.java:134)
Caused by: org.apache.poi.openxml4j.exceptions.InvalidOperationException: Operation not allowed, document open in read only mode!
	at org.apache.poi.openxml4j.opc.OPCPackage.throwExceptionIfReadOnly(OPCPackage.java:512)
	at org.apache.poi.openxml4j.opc.OPCPackage.createPart(OPCPackage.java:773)
	at org.apache.poi.openxml4j.opc.OPCPackage.createPart(OPCPackage.java:749)
	at org.apache.poi.POIXMLDocumentPart.createRelationship(POIXMLDocumentPart.java:374)

Can you try with POI 3.12 beta 1? There was a read-only fix in that

(In reply to Nick Burch from comment #7)
> Can you try with POI 3.12 beta 1? There was a read-only fix in that

Works (if you don't need write)!!

Update to POI 3.12 beta 1 and you open files in read only mode.

This is now fixed for empty shared string tables via r1710521, I put in a check to only avoid writing the XML file for SharedStringTable for now as doing it for all types of documents likely introduced trouble with existing code and broke unit tests. 

Please report new bugs if there are any other XML-parts that cause trouble if written empty.