4.2.4.2. Using the Bean

A reference to the bean can be obtained through injection or through the AppBeans class. As an example of using the bean, let us look at the implementation of the OrderService bean that delegates the execution to the OrderWorker bean:

package com.sample.sales.core;

import com.haulmont.cuba.core.Persistence;
import com.sample.sales.entity.Order;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;
import javax.inject.Inject;

@Service(OrderService.NAME)
public class OrderServiceBean implements OrderService {

    @Inject
    protected Persistence persistence;

    @Inject
    protected OrderWorker orderWorker;

    @Transactional
    @Override
    public BigDecimal calculateTotals(Order order) {
        Order entity = persistence.getEntityManager().merge(order);
        orderWorker.calculateTotals(entity);
    }
}

In this example, the service starts a transaction, merges the detached entity obtained from the client level into the persistent context, and passes the control to the OrderWorker bean, which contains the main business logic.