Error class not found when readObject from InputStream

[jmikel]

Hi everybody.

I try to write JRVirtualPrintPage object into OutputStream in order to wite it to persistence file.

But when i read  from InputStream, i couldn't load a class which i defined when perform percentile calculation

My code at below:

private void writePages() throws IOException, JRException {       OutputStream pos = new OutputStream();        ObjectOutputStream oos = new ObjectOutputStream(pos);               List pages = print.getPages();        numPages = pages == null ? 0 : pages.size();        writeInt(numPages);               pageFilePointers = new long[pages.size()];        long pfpOffset = writeObject(pageFilePointers);        for(int i = 0; i < numPages; i++)        {            if (interrupted)                return;                       if (Thread.currentThread().isInterrupted())            {                throw new JRException("Current thread interrupted.");            }            JRVirtualPrintPage vpage = (JRVirtualPrintPage)pages.get(i);                  oos.writeObject(vpage);                       for (JRPrintElement jrPrintElement : elements) {                oos.writeObject(jrPrintElement);            }                       pageFilePointers[i] = writeBytes(pos.getBytes());        }        long saveFP = file.getFilePointer();        file.seek(pfpOffset);        writeObject(pageFilePointers);        file.seek(saveFP);    }    private void readPages() throws IOException, ClassNotFoundException {        int numPages = readInt();        pageFilePointers = (long[])readObject();        AJPersistenceInputStream pis = new AJPersistenceInputStream();        file.seek(pageFilePointers[0]);        byte[] pageBytes = readBytes();        pis.reset(pageBytes);        ObjectInputStream ois = new ObjectInputStream(pis);        JRVirtualPrintPage page = (JRVirtualPrintPage)ois.readObject();                      if (startIndex == endIndex) {            for(int i=1; i<=startIndex; i++)                page = getPrintPage(pis, ois, i);            print.addPage(page);        }        else {            endIndex = Math.min(endIndex, pageFilePointers.length-1);            for(int i=0; i<=endIndex; i++) {                if (i>0)    // else already read page index == 0                    page = getPrintPage(pis, ois, i);                if (i >= startIndex)                    print.addPage(page);            }        }    }[/code]

I got an error at below:

java.lang.ClassNotFoundException: com.alu.vital.vq.jasper.aggregation.AJPercentileAggregator        at java.net.URLClassLoader$1.run(URLClassLoader.java:366)        at java.net.URLClassLoader$1.run(URLClassLoader.java:355)        at java.security.AccessController.doPrivileged(Native Method)        at java.net.URLClassLoader.findClass(URLClassLoader.java:354)        at java.lang.ClassLoader.loadClass(ClassLoader.java:424)        at java.lang.ClassLoader.loadClass(ClassLoader.java:357)        at java.lang.Class.forName0(Native Method)        at java.lang.Class.forName(Class.java:270)        at java.io.ObjectInputStream.resolveClass(ObjectInputStream.java:623)        at java.io.ObjectInputStream.readNonProxyDesc(ObjectInputStream.java:1610)        at java.io.ObjectInputStream.readClassDesc(ObjectInputStream.java:1515)        at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1769)        at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1348)        at java.io.ObjectInputStream.defaultReadFields(ObjectInputStream.java:1989)        at java.io.ObjectInputStream.defaultReadObject(ObjectInputStream.java:499)        at net.sf.jasperreports.engine.fill.JRTemplatePrintText.readObject(JRTemplatePrintText.java:901)        at sun.reflect.GeneratedMethodAccessor35.invoke(Unknown Source)        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)        at java.lang.reflect.Method.invoke(Method.java:606)        at java.io.ObjectStreamClass.invokeReadObject(ObjectStreamClass.java:1017)        at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1891)        at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1796)        at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1348)        at java.io.ObjectInputStream.readObject(ObjectInputStream.java:370)        at java.util.ArrayList.readObject(ArrayList.java:733)        at sun.reflect.GeneratedMethodAccessor36.invoke(Unknown Source)        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)        at java.lang.reflect.Method.invoke(Method.java:606)        at java.io.ObjectStreamClass.invokeReadObject(ObjectStreamClass.java:1017)        at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1891)        at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1796)        at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1348)        at java.io.ObjectInputStream.defaultReadFields(ObjectInputStream.java:1989)        at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1913)        at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1796)        at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1348)        at java.io.ObjectInputStream.readObject(ObjectInputStream.java:370)        at java.util.ArrayList.readObject(ArrayList.java:733)        at sun.reflect.GeneratedMethodAccessor36.invoke(Unknown Source)        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)        at java.lang.reflect.Method.invoke(Method.java:606)        at java.io.ObjectStreamClass.invokeReadObject(ObjectStreamClass.java:1017)        at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1891)        at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1796)        at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1348)        at java.io.ObjectInputStream.defaultReadFields(ObjectInputStream.java:1989)        at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1913)        at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1796)        at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1348)        at java.io.ObjectInputStream.readObject(ObjectInputStream.java:370)        at java.util.ArrayList.readObject(ArrayList.java:733)        at sun.reflect.GeneratedMethodAccessor36.invoke(Unknown Source)        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)        at java.lang.reflect.Method.invoke(Method.java:606)        at java.io.ObjectStreamClass.invokeReadObject(ObjectStreamClass.java:1017)        at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1891)        at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1796)        at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1348)        at java.io.ObjectInputStream.defaultReadFields(ObjectInputStream.java:1989)        at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1913)        at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1796)        at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1348)        at java.io.ObjectInputStream.readObject(ObjectInputStream.java:370)        at java.util.ArrayList.readObject(ArrayList.java:733)        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)        at java.lang.reflect.Method.invoke(Method.java:606)        at java.io.ObjectStreamClass.invokeReadObject(ObjectStreamClass.java:1017)        at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1891)        at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1796)        at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1348)        at java.io.ObjectInputStream.readObject(ObjectInputStream.java:370)        at net.sf.jasperreports.engine.base.ElementsBlock.readObject(VirtualizableElementList.java:567)        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)        at java.lang.reflect.Method.invoke(Method.java:606)        at java.io.ObjectStreamClass.invokeReadObject(ObjectStreamClass.java:1017)        at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1891)        at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1796)        at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1348)        at java.io.ObjectInputStream.defaultReadFields(ObjectInputStream.java:1989)        at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1913)        at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1796)        at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1348)        at java.io.ObjectInputStream.readObject(ObjectInputStream.java:370)        at net.sf.jasperreports.engine.base.JRVirtualPrintPage.readObject(JRVirtualPrintPage.java:241)        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)        at java.lang.reflect.Method.invoke(Method.java:606)        at java.io.ObjectStreamClass.invokeReadObject(ObjectStreamClass.java:1017)        at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1891)        at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1796)        at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1348)        at java.io.ObjectInputStream.readObject(ObjectInputStream.java:370)        at com.alu.vital.vq.jasper.reportserver.AJPersistenceManager.readPages(AJPersistenceManager.java:333)[/code]

The "com.alu.vital.vq.jasper.aggregation.AJPercentileAggregator" class is class which i defined to perform percentile calculation. It was compiled when build report.

Why do i use JRVirtualPrintPage object to write into OutputStream and when read from InputStream, i also cast object to JRVirtualPrintPage type, why does this exception occur?

Please help me explain more details this. And how can i fix it? I think it relave to new Virtualize mechanism becaue this issue only occurs when i upgrade Jasper from 3.7.4 to 5.0.1

Thanks,

jMikel

[nthapa]

Are you trying to read in pages that were written by older JRS, There might be two version of the same classes as a result of upgrade. I suspect that is the case. If so please clear everything and start from writing again.