POF Exception , java.io.IOException: previous property index=4...

Question

I am getting the following error when the following application code runs:
public void testPOF() {
Token T1 = new Token(1,1,"Toronto",3,5);
NamedCache aceCache = CacheFactory.getCache("ACE");
aceCache.put("TokenTest1", T1);
Token T2 = (Token) aceCache.get("AnkitAsthana");
if (T1.getNeID().equals(T1.getNeID())) {
System.out.println(" Works and equal ");
System.out.println("===============\n");
As you might already guess Token is a POF object , its artifacts are attached below. Coherence-cache-server seemed to startup fine.
<Oct 13, 2011 7:56:47 PM PDT> <Warning> <EJB> <BEA-010065> <MessageDrivenBean threw an Exception in onMessage(). The exception was:
(Wrapped) java.io.IOException: previous property index=4, requested property index=1 while writing user type 1001.
(Wrapped) java.io.IOException: previous property index=4, requested property index=1 while writing user type 1001
at com.tangosol.util.ExternalizableHelper.toBinary(ExternalizableHelper.java:215)
at com.tangosol.coherence.component.util.daemon.queueProcessor.service.grid.partitionedService.PartitionedCache$ConverterValueToBinary.convert(PartitionedCache.CDB:3)
at com.tangosol.util.ConverterCollections$ConverterMap.put(ConverterCollections.java:1578)
Plz help I have no idea what the issue is?
======================================================================================================================
tokens-pof-config.xml
======================================================================================================================
<?xml version="1.0"?>
<pof-config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns="http://xmlns.oracle.com/coherence/coherence-pof-config"
xsi:schemaLocation="http://xmlns.oracle.com/coherence/coherence-pof-config coherence-pof-config.xsd">
<user-type-list>
<!-- coherence POF user types -->
<include>coherence-pof-config.xml</include>
<!-- com.tangosol.examples package -->
<user-type>
<type-id>1001</type-id>
<class-name>Token</class-name>
</user-type>
</user-type-list>
<allow-interfaces>true</allow-interfaces>
<allow-subclasses>true</allow-subclasses>
</pof-config>
======================================================================================================================
Token.java
======================================================================================================================
import java.io.IOException;
import java.io.Serializable;
import com.tangosol.io.pof.PortableObject;
import com.tangosol.io.pof.PofReader;
import com.tangosol.io.pof.PofWriter;
import java.sql.*;
import java.util.Enumeration;
public class Token implements PortableObject {
     * 1 - Unassigned
     * 2 - Available
     * 3 - Reserved
     * 4 - defunct
     private int state;
     * NE-ID(s)
     private String neID;
     * Number of tokens currently Active
     private int tokensCurrentlyActive;
     * Max - Number of tokens available
     private int maxTokensAvailable;
     * unqiue Token ID, used to identify Tokens
     private int tokenID;
     * POF index for data members
     public static final int TOKENID = 0;
     public static final int STATE = 1;
     public static final int NEID = 2;     
     public static final int CURTOKEN = 3;
     public static final int MAXTOKEN = 4;
     * @param state
     public void setState(int state) {
          this.state = state;
     * @return
     public int getState() {
          return state;
     * @param neID
     public void setNeID(String neID) {
          this.neID = neID;
     * @return
     public String getNeID() {
          return neID;
     * @param tokensCurrentlyActive
     public void setTokensCurrentlyActive(int tokensCurrentlyActive) {
          this.tokensCurrentlyActive = tokensCurrentlyActive;
     * @return
     public int getTokensCurrentlyActive() {
          return tokensCurrentlyActive;
     * @param maxTokensAvailable
     public void setMaxTokensAvailable(int maxTokensAvailable) {
          this.maxTokensAvailable = maxTokensAvailable;
     * @return
     public int getMaxTokensAvailable() {
          return maxTokensAvailable;
     * @param tokenID
     public void setTokenID(int tokenID) {
          this.tokenID = tokenID;
     * @return
     public int getTokenID() {
          return tokenID;
     public Token(int state, int tokenID, String neID, int maxTokensAvailable, int tokensCurrentlyActive){
     this.state = state;
     this.tokenID = tokenID;
     this.neID = "Toronto";
     this.maxTokensAvailable = maxTokensAvailable;
     this.tokensCurrentlyActive = tokensCurrentlyActive;
     // ----- PortableObject interface ---------------------------------------
* {@inheritDoc}
public void readExternal(PofReader reader)
          throws IOException
tokenID = Integer.parseInt(reader.readString(TOKENID));
     neID = reader.readString(NEID);
     tokensCurrentlyActive = Integer.parseInt(reader.readString(CURTOKEN));
     maxTokensAvailable = Integer.parseInt(reader.readString(MAXTOKEN));
state = Integer.parseInt(reader.readString(STATE));
* {@inheritDoc}
public void writeExternal(PofWriter writer)
          throws IOException
writer.writeString(TOKENID,Integer.toString(tokenID));
writer.writeString(NEID,neID);
writer.writeString(CURTOKEN,Integer.toString(CURTOKEN));
writer.writeString(MAXTOKEN,Integer.toString(MAXTOKEN));
writer.writeString(STATE,Integer.toString(STATE));
======================================================================================================================
coherence-cache-config.xml
======================================================================================================================
<distributed-scheme>
<scheme-name>example-distributed</scheme-name>
<service-name>DistributedCache</service-name>
<serializer>
<class-name>com.tangosol.io.pof.ConfigurablePofContext</class-name>
<init-params>
<init-param>
<param-type>string</param-type>
<param-value>tokens-pof-config.xml</param-value>
</init-param>
</init-params>
</serializer>
<backing-map-scheme>
<local-scheme>
<scheme-ref>example-binary-backing-map</scheme-ref>
</local-scheme>
</backing-map-scheme>
<autostart>true</autostart>
</distributed-scheme>

Answer 1

Your read and write methods are wrong.
your constants are:
public static final int TOKENID = 0;
public static final int STATE = 1;
public static final int NEID = 2;     
public static final int CURTOKEN = 3;
public static final int MAXTOKEN = 4;your readExternal and writeExternal methods are...
public void readExternal(PofReader reader)
throws IOException
    tokenID = Integer.parseInt(reader.readString(TOKENID));
    neID = reader.readString(NEID);
    tokensCurrentlyActive = Integer.parseInt(reader.readString(CURTOKEN));
    maxTokensAvailable = Integer.parseInt(reader.readString(MAXTOKEN));
    state = Integer.parseInt(reader.readString(STATE));
public void writeExternal(PofWriter writer)
throws IOException
    writer.writeString(TOKENID,Integer.toString(tokenID));
    writer.writeString(NEID,neID);
    writer.writeString(CURTOKEN,Integer.toString(CURTOKEN));
    writer.writeString(MAXTOKEN,Integer.toString(MAXTOKEN));
    writer.writeString(STATE,Integer.toString(STATE));
}so the order you are writing the fields is 0, 2, 3, 4, 1 which you cannot do as with POF you must always write the fields in numerical oeder of the POF ID.
Like this...
public void readExternal(PofReader reader)
throws IOException
    tokenID = Integer.parseInt(reader.readString(TOKENID));
    state = Integer.parseInt(reader.readString(STATE));
    neID = reader.readString(NEID);
    tokensCurrentlyActive = Integer.parseInt(reader.readString(CURTOKEN));
    maxTokensAvailable = Integer.parseInt(reader.readString(MAXTOKEN));
public void writeExternal(PofWriter writer)
throws IOException
    writer.writeString(TOKENID,Integer.toString(tokenID));
    writer.writeString(STATE,Integer.toString(STATE));
    writer.writeString(NEID,neID);
    writer.writeString(CURTOKEN,Integer.toString(CURTOKEN));
    writer.writeString(MAXTOKEN,Integer.toString(MAXTOKEN));
}For Pof ID values you can use any int you like and you can have gaps (so you could use 100, 200, 300 etc...) but they must always be written and read in order.
JK