Hi, I am facing a very common problem. I am not able to remove an entity from datatable. My entity class is:

Code:
public class ElectricDeviceEntity implements DeviceEntityInterface {
	
	@Id
	private int Id;
	private String name;
	@ManyToOne(optional=false,cascade=CascadeType.ALL,targetEntity=ProfileEntity.class)
	@JoinColumn(name="profile", referencedColumnName="id")
	private ProfileEntity profileEntity;
	private int device;
	@ManyToOne(optional=false,cascade=CascadeType.ALL,targetEntity=PortEntity.class)
	@JoinColumn(name="port", referencedColumnName="id")
	private PortEntity portEntity;
    // getters and setters
}
My Dao class is:


Code:
public class ElectricDeviceDao implements DeviceServiceInterface{
	
	@PersistenceContext
	protected EntityManager entityManager;
	private ElectricDeviceEntity deviceEntity;
	
	private void InterfaceToEntity(DeviceEntityInterface deviceEntity)
	{
		this.deviceEntity = (ElectricDeviceEntity)deviceEntity;
	}
	
public void deleteDevice(DeviceEntityInterface deviceEntityInterface)
	{
		InterfaceToEntity(deviceEntityInterface);
		deviceEntity = entityManager.merge(deviceEntity);
		entityManager.remove(this.deviceEntity);
		entityManager.flush();
	}
}

My service class is:

Code:
public class ElectricDeviceService implements DeviceServiceInterface{
	
	@Autowired
   ElectricDeviceDao deviceDao;
	
		public void deleteDevice(DeviceEntityInterface deviceEntityInterface)
	{
		deviceDao.deleteDevice(deviceEntityInterface);
	}
}
And my spring-config xml file is:

Code:
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
           xmlns:aop="http://www.springframework.org/schema/aop"
            xmlns:context="http://www.springframework.org/schema/context" xmlns:jee="http://www.springframework.org/schema/jee"
            xmlns:tx="http://www.springframework.org/schema/tx"
xsi:schemaLocation="
http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.0.xsd
http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd
http://www.springframework.org/schema/jee http://www.springframework.org/schema/jee/spring-jee-3.0.xsd
http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.0.xsd">

<context:component-scan base-package="com.infosys.ingreen.middleware.dao" />


<bean class="org.springframework.orm.jpa.support.PersistenceAnnotationBeanPostProcessor" />  

<bean id="entityManagerFactory" 
class="org.springframework.orm.jpa.LocalEntityManagerFactoryBean"> 
<property name="persistenceUnitName" value="IngreenMiddleware"/>
 </bean>
 
<context:annotation-config/>


<bean id="transactionManager" 
class="org.springframework.orm.jpa.JpaTransactionManager">
<property name="entityManagerFactory" ref="entityManagerFactory"/> 
</bean>



<bean id="baseTransactionProxy" class="org.springframework.transaction.interceptor.TransactionProxyFactoryBean" abstract="true">
		<property name="transactionManager" ref="transactionManager"/>
		<property name="target"><ref bean="DeviceService"/></property>
		<property name="transactionAttributes">
			<props>
				<prop key="add*">PROPAGATION_REQUIRED</prop>
				<prop key="update*">PROPAGATION_REQUIRED</prop>
				<prop key="get*">PROPAGATION_REQUIRED</prop>
				<prop key="deleteDevice*">PROPAGATION_REQUIRED</prop>
			</props>
		</property>
		
	</bean>

<bean id="DeviceService" class="com.infosys.ingreen.middleware.service.ElectricDeviceService"/>


</beans>
What can be the reason behind this error:

Entity must be managed to call remove: com.infosys.ingreen.middleware.entity.ElectricDevi ceEntity@908881, try merging the detached and try the remove again.