Help Needed in persisting data in cache from CEP on to a database

Question

Hi,
We are trying to create a Oracle Complex Event Processing (CEP) application in which persist the data stored in the cache (Oracle Coherence) to a back end database
Let me provide you the steps that I have followed:
1)     Created a CEP project with cache implementation to store the events.
2)     Have the following configuration in the context file:
<wlevs:cache id="Task_IN_Cache" value-type="Task" key-properties="TASKID" caching-system="CachingSystem1">
<wlevs:cache-store ref="cacheFacade"></wlevs:cache-store>
</wlevs:cache>
<wlevs:caching-system id="CachingSystem1" provider="coherence">
<bean id="cacheFacade" class="com.oracle.coherence.handson.DBCacheStore">
</bean>
3)     Have the following in the coherence cache config xml:
<cache-mapping>
<cache-name>Task_IN_Cache</cache-name>
<scheme-name>local-db-backed</scheme-name>
</cache-mapping>
<local-scheme>
<scheme-name>local-db-backed</scheme-name>
<service-name>LocalCache</service-name>
<backing-map-scheme>
<read-write-backing-map-scheme>
<internal-cache-scheme>
<local-scheme/>
</internal-cache-scheme>
<cachestore-scheme>
<class-scheme>
<class-name>com.oracle.coherence.handson.DBCacheStore</class-name>
</class-scheme>
</cachestore-scheme>
</read-write-backing-map-scheme>
</backing-map-scheme>
</local-scheme>
4)     Have configured tangosol-coherence-override.xml to make use of coherence in my local machine.
5)     Have written a class that implements com.tangosol.net.cache.CacheStore
public class DBCacheStore implements CacheStore{
But when I try to deploy the project on to the CEP server getting the below error:
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'Task_IN_AD': Cannot resolve reference to bean 'wlevs_stage_proxy_forTask_IN_Cache' while setting bean property 'listeners' with key [0]; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'wlevs_stage_proxy_forTask_IN_Cache': Cannot resolve reference to bean '&Task_IN_Cache' while setting bean property 'cacheFactoryBean'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'Task_IN_Cache': Invocation of init method failed; nested exception is java.lang.RuntimeException: Error while deploying application 'AIT_Caching'. Cache store specified for cache 'Task_IN_Cache' does not implement the required 'com.tangosol.net.cache.CacheStore' interface.
Can you please let me know if I am missing any configuration. Appreciate your help.

Answer 1

Hi JK,
Yes my class com.oracle.coherence.handson.DBCacheStore implements the com.tangosol.net.cache.CacheStore interface. I am providing you with the DBCacheStore class.
package com.oracle.coherence.handson;
import com.tangosol.net.CacheFactory;
import com.tangosol.net.NamedCache;
import com.tangosol.net.cache.CacheStore;
import java.sql.DriverManager;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.Collection;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import oracle.jdbc.pool.OracleDataSource;
public class DBCacheStore implements CacheStore {
protected Connection m_con;
protected String m_sTableName;
private static final String DB_DRIVER = "oracle.jdbc.OracleDriver";
private static final String DB_URL = "jdbc:oracle:thin:@XXXX:1521:XXXX";
private static final String DB_USERNAME = "XXXX";
private static final String DB_PASSWORD = "XXXX";
public DBCacheStore()
m_sTableName = "TASK";
System.out.println("Inside constructor");
init();
//store("10002", "10002");
public void init()
try
     OracleDataSource ods = new OracleDataSource();
/* Class.forName(DB_DRIVER);
m_con = DriverManager.getConnection(DB_URL, DB_USERNAME, DB_PASSWORD);
m_con.setAutoCommit(true);*/
     ods.setURL(DB_URL);
     ods.setUser(DB_USERNAME);
     ods.setPassword(DB_PASSWORD);
     m_con = ods.getConnection();
System.out.println("Connection Successful");
catch (Exception e)
     e.printStackTrace();
//throw ensureRuntimeException(e, "Connection failed");
public String getTableName() {
return m_sTableName;
public Connection getConnection()
return m_con;
public Object load(Object oKey)
Object oValue = null;
Connection con = getConnection();
String sSQL = "SELECT TASKID, REQNUMBER FROM " + getTableName()
+ " WHERE TASKID = ?";
try
PreparedStatement stmt = con.prepareStatement(sSQL);
stmt.setString(1, String.valueOf(oKey));
ResultSet rslt = stmt.executeQuery();
if (rslt.next())
oValue = rslt.getString(2);
if (rslt.next())
throw new SQLException("Not a unique key: " + oKey);
stmt.close();
catch (SQLException e)
//throw ensureRuntimeException(e, "Load failed: key=" + oKey);
return oValue;
public void store(Object oKey, Object oValue)
     System.out.println("Inside Store method");
     NamedCache cache = CacheFactory.getCache("Task_IN_Cache");
     System.out.println("Cache Service:" + " "+ cache.getCacheService());
     System.out.println("Cache Size:" + " "+ cache.size());
     System.out.println("Is Active:" + " "+ cache.isActive());
     System.out.println("Is Empty:" + " "+ cache.isEmpty());
     //cache.put("10003", "10003");
     //System.out.println("Values:" + " "+ cache.put("10003", "10003"));
Connection con = getConnection();
String sTable = getTableName();
String sSQL;
if (load(oKey) != null)
sSQL = "UPDATE " + sTable + " SET REQNUMBER = ? where TASKID = ?";
else
sSQL = "INSERT INTO " + sTable + " (TASKID, REQNUMBER) VALUES (?,?)";
try
PreparedStatement stmt = con.prepareStatement(sSQL);
int i = 0;
stmt.setString(++i, String.valueOf(oValue));
stmt.setString(++i, String.valueOf(oKey));
stmt.executeUpdate();
stmt.close();
catch (SQLException e)
//throw ensureRuntimeException(e, "Store failed: key=" + oKey);
public void erase(Object oKey)
Connection con = getConnection();
String sSQL = "DELETE FROM " + getTableName() + " WHERE id=?";
try
PreparedStatement stmt = con.prepareStatement(sSQL);
stmt.setString(1, String.valueOf(oKey));
stmt.executeUpdate();
stmt.close();
catch (SQLException e)
// throw ensureRuntimeException(e, "Erase failed: key=" + oKey);
public void eraseAll(Collection colKeys)
throw new UnsupportedOperationException();
public Map loadAll(Collection colKeys) {
throw new UnsupportedOperationException();
public void storeAll(Map mapEntries)
     System.out.println("Inside Store method");
throw new UnsupportedOperationException();
public Iterator keys()
Connection con = getConnection();
String sSQL = "SELECT id FROM " + getTableName();
List list = new LinkedList();
try
PreparedStatement stmt = con.prepareStatement(sSQL);
ResultSet rslt = stmt.executeQuery();
while (rslt.next())
Object oKey = rslt.getString(1);
list.add(oKey);
stmt.close();
catch (SQLException e)
//throw ensureRuntimeException(e, "Iterator failed");
return list.iterator();
}