topic Classloader trouble while deserializing process variables in Alfresco Archive https://connect.hyland.com/t5/alfresco-archive/classloader-trouble-while-deserializing-process-variables/m-p/48607#M27838 <HTML><HEAD></HEAD><BODY><SPAN>Hi,</SPAN><BR /><BR /><SPAN>I'm using activiti in a Grails project and having trouble when it comes to deserializing Groovy objects that are stored in process variables. I'm experiencing pretty much the same problems as described in this post (not using the Grails Avticiti plugin, though): </SPAN><A href="http://code.google.com/p/grails-activiti-plugin/issues/detail?id=16" rel="nofollow noopener noreferrer">http://code.google.com/p/grails-activiti-plugin/issues/detail?id=16</A><BR /><SPAN>To sum it up, deserializing my objects fails with a ClassNotFoundException, which is due to the wrong ClassLoader being used.</SPAN><BR /><BR /><SPAN>I came up with a workaround employing the suggested solution from </SPAN><A href="http://jira.codehaus.org/browse/GROOVY-1627" rel="nofollow noopener noreferrer">http://jira.codehaus.org/browse/GROOVY-1627</A><SPAN>, which is to subclass ObjectInputStream and overriding the resolveClass method in order to use a specific class loader (in my case the grailsApplication.classLoader). The workaround seems to work but it is rather ugly and I am wondering, if there is a better solution to my problem.</SPAN><BR /><BR /><SPAN>Here's my approach: In order to tap into the process of deserializing process variables, I subclass the Activiti SerializableType and override the getValue method, which is the place where deserialization happens. I basically copy-pasted the SerializableType's implementation an replaced the ObjectInputStream with my custom implementation. During application startup I register my custom SerializableType with the ProcessEngineConfiguration.</SPAN><BR /><SPAN>Here's my Grails service that does all that: </SPAN><BR /><BR /><PRE class="language-none line-numbers"><CODE>class CustomSerializableProcessTypeService {<BR /><BR />&nbsp;&nbsp;&nbsp; static transactional = false<BR /><BR />&nbsp;&nbsp;&nbsp; ProcessEngineConfigurationImpl processEngineConfiguration<BR />&nbsp;&nbsp;&nbsp; def grailsApplication<BR /><BR />&nbsp;&nbsp;&nbsp; void registerCustomSerializableType () {<BR />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; processEngineConfiguration.variableTypes.addType (new CustomSerializableType (), 0)<BR />&nbsp;&nbsp;&nbsp; }<BR /><BR />&nbsp;&nbsp;&nbsp; class CustomSerializableType extends SerializableType {<BR />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; @Override<BR />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Object getValue (ValueFields valueFields) {<BR />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Object cachedObject = valueFields.getCachedValue ();<BR />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; if (cachedObject != null) {<BR />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; return cachedObject;<BR />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; }<BR />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; byte[] bytes = valueFields.getByteArrayValue ()?.getBytes ();<BR />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; ByteArrayInputStream bais = new ByteArrayInputStream (bytes);<BR />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Object deserializedObject = null;<BR />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; try {<BR />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; ObjectInputStream ois = new CustomObjectInputStream (bais)&nbsp; // &lt;=== This is the line of interest<BR />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; deserializedObject = ois.readObject ();<BR />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; valueFields.setCachedValue (deserializedObject);<BR /><BR />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; if (valueFields instanceof VariableInstanceEntity) {<BR />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Context.<BR />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; getCommandContext ().<BR />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; getDbSqlSession ().<BR />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; addDeserializedObject (deserializedObject, bytes, (VariableInstanceEntity) valueFields);<BR />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; }<BR /><BR />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; } catch (Exception e) {<BR />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; log.warn ("exception occurred in getValue of custom SerializableType, trying super class", e)<BR />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; } finally {<BR />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; IoUtil.closeSilently (bais);<BR />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; }<BR /><BR /><BR />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; if (deserializedObject) {<BR />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; return deserializedObject;<BR />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; }<BR />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; return super.getValue (valueFields)<BR />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; }<BR />&nbsp;&nbsp;&nbsp; }<BR /><BR />&nbsp;&nbsp;&nbsp; class CustomObjectInputStream extends ObjectInputStream {<BR /><BR />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; CustomObjectInputStream (InputStream inputStream) {<BR />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; super(inputStream)<BR />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; }<BR /><BR />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; protected Class resolveClass (ObjectStreamClass objectStreamClass) throws IOException, ClassNotFoundException {<BR />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; return Class.forName (objectStreamClass.getName (), true, grailsApplication.classLoader);<BR />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; }<BR />&nbsp;&nbsp;&nbsp; }<BR />}<SPAN class="line-numbers-rows"><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN></SPAN></CODE></PRE><BR /><SPAN>So here are my questions:</SPAN><BR /><BR /><SPAN>1. Is there a better way fix the ClassLoader issue?</SPAN><BR /><BR /><SPAN>2. If not, is there a better way to register custom VariableTypes? I'm currently using the ProcessEngineConfigurationImpl's VaraibleTypes object, which isn't even exposed by the ProcessEngineConfiguration interface. (By the way, I'm having a hard time to find documentation on this.)</SPAN><BR /><BR /><SPAN>I appreciate any hints! </SPAN><BR /><BR /><SPAN>Thanks a lot</SPAN><BR /><SPAN>Daniel</SPAN></BODY></HTML> Fri, 11 Nov 2011 09:15:32 GMT danielbehrwind 2011-11-11T09:15:32Z Classloader trouble while deserializing process variables https://connect.hyland.com/t5/alfresco-archive/classloader-trouble-while-deserializing-process-variables/m-p/48607#M27838 Hi,I'm using activiti in a Grails project and having trouble when it comes to deserializing Groovy objects that are stored in process variables. I'm experiencing pretty much the same problems as described in this post (not using the Grails Avticiti plugin, though): http://code.google.com/p/grails-ac Fri, 11 Nov 2011 09:15:32 GMT https://connect.hyland.com/t5/alfresco-archive/classloader-trouble-while-deserializing-process-variables/m-p/48607#M27838 danielbehrwind 2011-11-11T09:15:32Z Re: Classloader trouble while deserializing process variables https://connect.hyland.com/t5/alfresco-archive/classloader-trouble-while-deserializing-process-variables/m-p/48608#M27839 <HTML><HEAD></HEAD><BODY><SPAN>Hi,</SPAN><BR /><BR /><SPAN>I think the Grails plugin project would be a better place to raise this question.</SPAN><BR /><BR /><SPAN>Best regards,</SPAN></BODY></HTML> Sat, 12 Nov 2011 11:01:07 GMT https://connect.hyland.com/t5/alfresco-archive/classloader-trouble-while-deserializing-process-variables/m-p/48608#M27839 trademak 2011-11-12T11:01:07Z