Caused by: com.ubs.eq.del.stomp.core.persistence.StompPersistenceException: org.hibernate.PropertyAccessException: could not get a field value by reflection getter of com.ubs.eq.del.rmp.model.order.ExternalSystemOrderIdentifier.clientOrderId
   at com.ubs.eq.del.stomp.core.persistence.hibernate.HibernatePersistence.executeInTransaction(HibernatePersistence.java:114)
   at com.ubs.eq.del.stomp.core.persistence.hibernate.HibernatePersistenceClosureFactory$1Closure.execute(HibernatePersistenceClosureFactory.java:13)
   at com.ubs.eq.del.stomp.core.persistence.hibernate.HibernatePersistenceClosureFactory$1Closure.execute(HibernatePersistenceClosureFactory.java:1)
   at com.ubs.eq.del.stomp.core.persistence.hibernate.HibernatePersistence.withSession(HibernatePersistence.java:79)
   at com.ubs.eq.del.stomp.core.persistence.hibernate.HibernatePersistence.inTransaction(HibernatePersistence.java:87)
   at com.ubs.eq.del.stomp.core.persistence.StompNestedTransactions$1.execute(StompNestedTransactions.java:33)
   at com.ubs.eq.del.stomp.core.persistence.hibernate.HibernatePersistence$1.execute(HibernatePersistence.java:100)
   at com.ubs.eq.del.stomp.core.persistence.hibernate.HibernatePersistence.execute(HibernatePersistence.java:119)
   at com.ubs.eq.del.stomp.core.persistence.hibernate.HibernatePersistence.executeInTransaction(HibernatePersistence.java:111)
   ... 28 more
Caused by: org.hibernate.PropertyAccessException: could not get a field value by reflection getter of com.ubs.eq.del.rmp.model.order.ExternalSystemOrderIdentifier.clientOrderId
   at org.hibernate.property.DirectPropertyAccessor$DirectGetter.get(DirectPropertyAccessor.java:58)
   at org.hibernate.tuple.component.AbstractComponentTuplizer.getPropertyValue(AbstractComponentTuplizer.java:87)
   at org.hibernate.tuple.component.AbstractComponentTuplizer.getPropertyValues(AbstractComponentTuplizer.java:93)
   at org.hibernate.tuple.component.PojoComponentTuplizer.getPropertyValues(PojoComponentTuplizer.java:109)
   at org.hibernate.type.ComponentType.getPropertyValues(ComponentType.java:376)
   at org.hibernate.type.ComponentType.getHashCode(ComponentType.java:194)
   at org.hibernate.cache.QueryKey.generateHashCode(QueryKey.java:194)
   at org.hibernate.cache.QueryKey.<init>(QueryKey.java:173)
   at org.hibernate.cache.QueryKey.generateQueryKey(QueryKey.java:128)
   at org.hibernate.loader.Loader.listUsingQueryCache(Loader.java:2144)
   at org.hibernate.loader.Loader.list(Loader.java:2121)
   at org.hibernate.loader.criteria.CriteriaLoader.list(CriteriaLoader.java:118)
   at org.hibernate.impl.SessionImpl.list(SessionImpl.java:1597)
   at org.hibernate.impl.CriteriaImpl.list(CriteriaImpl.java:306)
   at org.hibernate.impl.CriteriaImpl.uniqueResult(CriteriaImpl.java:328)
   at com.ubs.eq.del.rmp.persistence.hibernate.HibernateOrderBook.find(HibernateOrderBook.java:41)

package com.jc.test;

import javax.persistence.Embeddable;

@Embeddable
public class ExternalSystemOrderIdentifier {

   private String sourceSystem;
   private Long externalId;
   
   public ExternalSystemOrderIdentifier() {
      // hibernate
   }
   
   public ExternalSystemOrderIdentifier(String sourceSystem, Long externalId) {
      this.sourceSystem = sourceSystem;
      this.externalId = externalId;
   }

   public String getSourceSystem() {
      return sourceSystem;
   }

   public Long getExternalId() {
      return externalId;
   }
}

package com.jc.test;

import javax.persistence.Embedded;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.Table;

@Entity
@Table(name = "orders")
public class Order {

   @Id
   @GeneratedValue(strategy = GenerationType.AUTO)
   private Long id;
   
   @Embedded
   private ExternalSystemOrderIdentifier externalIdentifier;
   private String symbol;
   private int quantity;
   private double price;
   
   public Order() {
      // hibernate
   }
   
   public Order(ExternalSystemOrderIdentifier externalIdentifier, String symbol, int quantity, double price) {
      this.externalIdentifier = externalIdentifier;
      this.symbol = symbol;
      this.quantity = quantity;
      this.price = price;
   }

   public ExternalSystemOrderIdentifier getExternalIdentifier() {
      return externalIdentifier;
   }

   public String getSymbol() {
      return symbol;
   }

   public int getQuantity() {
      return quantity;
   }

   public double getPrice() {
      return price;
   }
   
   public Long getId(){
      return id;
   }
}

package com.jc.test;

import java.util.List;

import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;
import org.hibernate.cfg.AnnotationConfiguration;
import org.hibernate.criterion.Restrictions;


public class OrderBook {

   private final SessionFactory sessionFactory = new AnnotationConfiguration().configure().buildSessionFactory();
   
   @SuppressWarnings("unchecked")
   public List<Order> find(ExternalSystemOrderIdentifier identifier) {
      Session session = sessionFactory.openSession();
      try {
         return session.createCriteria(Order.class).add(Restrictions.eq("externalIdentifier", identifier)).setCacheable(true).list();   
      } finally {
         session.close();   
      }
   }
   
   public void add(Order order) {
      Session session = sessionFactory.openSession();
      Transaction trans = session.beginTransaction();
      try {
         trans.begin();
         session.save(order);
         trans.commit();
      } finally {
         session.close();
      }
   }
}

package com.jc.test;

import static org.junit.Assert.assertEquals;

import org.junit.Test;

public class TestRunner {

   @Test
   public void testDodginess() {
      OrderBook orderBook = new OrderBook();
      Order order = new Order(new ExternalSystemOrderIdentifier("SomeSystem", 1l), "DE0009542977", 3000, 15.2);
      orderBook.add(order);
      assertEquals(1, orderBook.find(order.getExternalIdentifier()).size());
   }
}

<?xml version='1.0' encoding='utf-8'?>
<!DOCTYPE hibernate-configuration PUBLIC
"-//Hibernate/Hibernate Configuration DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">

<hibernate-configuration>
   <session-factory>
      <property name="connection.driver_class">oracle.jdbc.driver.OracleDriver</property>
      <property name="connection.url">...</property>
      <property name="connection.username">...</property>
      <property name="connection.password">...</property>
      <property name="transaction.factory_class">org.hibernate.transaction.JDBCTransactionFactory</property>
      <property name="hibernate.dialect">org.hibernate.dialect.OracleDialect</property>
      <property name="hibernate.dbcp.minIdle">10</property>
      <property name="hibernate.dbcp.maxIdle">10</property>
      <property name="hibernate.dbcp.initialSize">10</property>
      <property name="hibernate.dbcp.maxActive">10</property>
      <property name="hibernate.jdbc.batch_size">250</property>
      
      <property name="hibernate.cache.use_second_level_cache">true</property>
      <property name="hibernate.cache.use_query_cache">true</property>
      <property name="hibernate.cache.use_structured_entries">true</property>
      <property name="hibernate.cache.provider_class">org.hibernate.cache.EhCacheProvider</property>
      <property name="hibernate.generate_statistics">true</property>
      
      <property name="hibernate.dbcp.poolPreparedStatements">true</property>
      <property name="hibernate.dbcp.maxOpenPreparedStatements">10</property>
      <property name="hibernate.show_sql">false</property>
      <property name="hibernate.hbm2ddl.auto">create-drop</property>

      <mapping class="com.jc.test.Order" />

   </session-factory>
</hibernate-configuration>

positionalParameterTypes[i].getHashCode( positionalParameterValues[i], entityMode )