allKeys.java

    @Processor
    public List<Serializable> allKeys() throws ObjectStoreException {
        if (objectStore instanceof ListableObjectStore) {
            return ((ListableObjectStore<?>) objectStore).allKeys();
        } else {
            throw new UnsupportedOperationException("The objectStore [" + objectStore.getClass().getName() + "] does not support the operation allKeys");
        }
    }

jdbc-objectstore-config.xml

    <spring:beans>
        <spring:bean id="dataSource" class="com.mysql.jdbc.jdbc2.optional.MysqlDataSource" name="dataSource">
            <spring:property name="url" value="jdbc:mysql://localhost:3306/objectstoreTest?user=objectstore3&amp;password=objectstore3" />
        </spring:bean>
        <spring:bean name="jdbcStore" class="org.mule.transport.jdbc.store.JdbcObjectStore"> 
            <spring:property name="jdbcConnector" ref="jdbcConnector"></spring:property>  
            <spring:property name="insertQueryKey" value="insertQueryKey"></spring:property>  
            <spring:property name="selectQueryKey" value="selectQueryKey"></spring:property>  
            <spring:property name="deleteQueryKey" value="deleteQueryKey"></spring:property>  
            <spring:property name="clearQueryKey" value="clearQueryKey"></spring:property>  
        </spring:bean>  
    </spring:beans>
    <jdbc-ee:connector name="jdbcConnector" pollingFrequency="1000" dataSource-ref="dataSource" transactionPerMessage="false" doc:name="Database"> 
        <jdbc-ee:query key="insertQueryKey" value="insert into objectstoreTest.objectstore (k,v) values (?,?)"></jdbc-ee:query>  
        <jdbc-ee:query key="selectQueryKey" value="select k,v from objectstoreTest.objectstore where k = ?"></jdbc-ee:query>  
        <jdbc-ee:query key="deleteQueryKey" value="delete from objectstore where k = ?"></jdbc-ee:query>
        <jdbc-ee:query key="clearQueryKey" value="delete from objectstore"></jdbc-ee:query>   
    </jdbc-ee:connector>
    
    <objectstore:config name="ObjectStore" doc:name="ObjectStore" objectStore-ref="jdbcStore"></objectstore:config>

JdbcListableObjectStore_allKeys.java

	@SuppressWarnings("unchecked")
	@Override
	public List<Serializable> allKeys() throws ObjectStoreException {
		String allKeysQuery = this.getAllKeysQuery();
		List<String> result = (List<String>) this.query(allKeysQuery, this.listHandler);
        	return new ArrayList<Serializable>(result);
	}

JdbcListableObjectStore_retrieve.java

	@Override
	public Serializable retrieve(Serializable key) throws ObjectStoreException {
		Serializable res = super.retrieve(key);
		if (transformer == null) {
			return res;
		} else {
			try {
				return (Serializable) transformer.transform(res);
			} catch (TransformerException e) {
				e.printStackTrace();
				LOG.warn("Failed to transform result of object store retrieval to a Serializable. Returning the Serializable retrieved from object store without any transformation");
				return res;
			}
		}
	}

objectstore.sql

CREATE TABLE IF NOT EXISTS `objectstoreTest`.`objectstore` (
  `id` INT NOT NULL AUTO_INCREMENT,
  `k` VARCHAR(60) NULL,
  `v` BLOB NULL,
  PRIMARY KEY (`id`),
  UNIQUE INDEX `k_UNIQUE` (`k` ASC))
ENGINE = InnoDB;