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POwhat could modify the SerialVersionUID while serializing and storing in a Jarfile?
 

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  1. POwhat could modify the SerialVersionUID while serializing and storing in a Jarfile?
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    <p>I am facing some issues while serializing objects (I am using JBoss Drools, and want to store an ArrayList of KnowledgePackage).</p> <p>When I serialize the list, store the result in a file, and deserialize it, no problem occurs, so it works fine.</p> <p>But when I serialize the list, store the result in a byte stream, then save it in a JarFile, i cannot then deserialize the result, because of this error :</p> <pre><code>IOException during package import : java.util.ArrayList; local class incompatible: stream classdesc serialVersionUID = 8664875232659988799, local class serialVersionUID = 8683452581122892189 </code></pre> <p>So I think the issue is when I am saving the serialized object into a Jarfile entry. I think I am doing this right, because other files saved the same way in the Jarfile can correctly be read. And after using 'cmp' and 'hexdump', I have spotted that saving it it an jar causes a variation of one octet if the uuid, else the content is the same.</p> <p>I am really disappointed and can not state where the problem may be.</p> <p>What can modify the SerialVersionUID between two classes ? other than another vm version ?</p> <hr> <p>adding source code : exportToJar -> writeRulesPackageEntry -> writeEntry</p> <pre><code>/** * Writes content provided from a reader into a file contained in a jar. * * @param output the output stream to write on * @param entryName the name of the file that will contain reader data * @param contentReader * * @return the zip entry that has been created into the jar */ ZipEntry writeEntry(JarOutputStream output, String entryName, ByteArrayInputStream input) { if (output == null || entryName == null || entryName.trim().length() == 0 || input == null) { throw new NullPointerException("Null argument passed"); } ZipEntry entry = new ZipEntry(entryName); byte[] buffer = new byte[BUFFER_LENGTH]; try { output.putNextEntry(entry); int nRead; while ((nRead = input.read(buffer, 0, BUFFER_LENGTH)) &gt; 0) { output.write(buffer, 0, nRead); } output.closeEntry(); } catch (IOException e) { e.printStackTrace(); } return entry; } /** * Export rules files to a serialized object (ArrayList&lt;KnowledgePackage&gt;) into * an output stream, then write the output content as an entry of a jar. * * @param os the output jar to write in */ void writeRulesPackageEntry(JarOutputStream os) { // serialize objects and write them to the output stream ByteArrayOutputStream output = new ByteArrayOutputStream(); RulesPackaging rulesPackaging = new RulesPackaging(); rulesPackaging.exportResources(this.rules, output); // create a new input stream to read written objects from ByteArrayInputStream input = new ByteArrayInputStream(output.toByteArray()); this.writeEntry(os, Product.ENTRY_RULES_PACKAGE, input); } /** * Creates a JarFile containing resources. * * @param filename the exported jar filename * @return the jar as an object, null if an error occured */ public JarFile exportToJar(String filename) { FileOutputStream fOs; JarOutputStream jOs; JarFile jar = null; try { fOs = new FileOutputStream(filename); jOs = new JarOutputStream(fOs); this.writeRulesPackageEntry(jOs); jOs.close(); // construct a jar from the output jar jar = new JarFile(new File(filename)); } catch (IOException e) { e.printStackTrace(); } return jar; } </code></pre>
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    1. USErik Clairiot
    1. USErik Clairiot
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      1. POwhat could modify the SerialVersionUID while serializing and storing in a Jarfile?
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      1. POwhat could modify the SerialVersionUID while serializing and storing in a Jarfile?
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      1. VTUpMod
    1. COThis has nothing to do with uuid which is a completely separate topic; I've edited your question
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      1. POwhat could modify the SerialVersionUID while serializing and storing in a Jarfile?
      1. USoxbow_lakes
    2. COright, I confused myself with serialVersionUID and UUID. Thanks for editing.
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      1. POwhat could modify the SerialVersionUID while serializing and storing in a Jarfile?
      1. USErik Clairiot
 

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