Problem using a trained network with Encog in a JSP environment

Hi Jeff,

Thanks for your previous reply: I finally got a neural network that works perfectly and I saved it in a file to be used in a server with JSP.
The code I use in the webpage is:


<%@ page import="java.util.List"%>
<%@ page import="java.util.Iterator"%>
<%@ page import="java.io.*"%>
<%@ page import="org.encog.neural.data.*"%>
<%@ page import="org.encog.neural.data.basic.BasicNeuralDataSet"%>
<%@ page import="org.encog.neural.data.csv.CSVNeuralDataSet"%>
<%@ page import="org.encog.neural.networks.*"%>
<%@ page import="org.encog.neural.networks.layers.*"%>
<%@ page import="org.encog.neural.networks.training.backpropagation.Backpropagation"%>
<%!
BasicNetwork restoreNeuralNet(String fileName) {
FileInputStream inn;
BasicNetwork network = null;
try {
inn = new FileInputStream(fileName);
ObjectInputStream s = new ObjectInputStream(inn);
network = (BasicNetwork)s.readObject();
return network;
} catch (FileNotFoundException e) { e.printStackTrace();
} catch (IOException e) { e.printStackTrace();
} catch (ClassNotFoundException e) { e.printStackTrace(); }
return network;
}
%>
...
<%
// Set path variable at '/uploads'
String serverUploadPath = application.getRealPath("/") + "uploads/";

BasicNetwork network = this.restoreNeuralNet(serverUploadPath + "nnet.snet");
if (network != null) {
NeuralDataSet trainingSet = new CSVNeuralDataSet(serverUploadPath + "input.txt",2500,1,false,';');
// test the neural network
out.println("Neural Network Results:");
for(NeuralDataPair pair: trainingSet ) {
final NeuralData output = network.compute(pair.getInput());
out.println(pair.getInput().getData(0) + "," + pair.getInput().getData(1)
+ ", actual=" + output.getData(0) + ",ideal=" + pair.getIdeal().getData(0));
}
}
%>

I've used that exact code in a desktop application I've developed and it works perfectly, but for some reason, when I try to execute it in the server with Tomcat 6.0 I get this exception:


Jun 25, 2009 11:09:53 PM org.apache.catalina.core.StandardWrapperValve invoke
SEVERE: Servlet.service() for servlet jsp threw exception
java.lang.ClassCastException: cannot assign instance of org.encog.neural.networks.layers.FeedforwardLayer to field org.encog.neural.networks.layers.BasicLayer.next of type java.util.List in instance of org.encog.neural.networks.layers.FeedforwardLayer
at java.io.ObjectStreamClass$FieldReflector.setObjFieldValues(ObjectStreamClass.java:2004)
at java.io.ObjectStreamClass.setObjFieldValues(ObjectStreamClass.java:1184)
at java.io.ObjectInputStream.defaultReadFields(ObjectInputStream.java:1916)
at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1834)
at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1719)
at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1305)
at java.io.ObjectInputStream.defaultReadFields(ObjectInputStream.java:1910)
at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1834)
at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1719)
at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1305)
at java.io.ObjectInputStream.defaultReadFields(ObjectInputStream.java:1910)
at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1834)
at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1719)
at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1305)
at java.io.ObjectInputStream.readObject(ObjectInputStream.java:348)
at org.apache.jsp.neural_jsp.restoreNeuralNet(neural_jsp.java:26)
at org.apache.jsp.neural_jsp._jspService(neural_jsp.java:111)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:374)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:342)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:267)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.valves.RequestFilterValve.process(RequestFilterValve.java:269)
at org.apache.catalina.valves.RemoteAddrValve.invoke(RemoteAddrValve.java:81)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:286)
at org.apache.coyote.http11.Http11AprProcessor.process(Http11AprProcessor.java:857)
at org.apache.coyote.http11.Http11AprProtocol$Http11ConnectionHandler.process(Http11AprProtocol.java:565)
at org.apache.tomcat.util.net.AprEndpoint$Worker.run(AprEndpoint.java:1509)
at java.lang.Thread.run(Thread.java:613)


I would appreciate if you could help me or orientate me on this.
Thank you very much in advance.

Liboh