[jira] [Created] (ARIES-1288) ClassCastException with proxy set in bean of generic class

["Ancoron Luciferis (JIRA)" <ji...@apache.org>]

Ancoron Luciferis created ARIES-1288:
----------------------------------------

             Summary: ClassCastException with proxy set in bean of generic class
                 Key: ARIES-1288
                 URL: https://issues.apache.org/jira/browse/ARIES-1288
             Project: Aries
          Issue Type: Bug
          Components: Blueprint
    Affects Versions: blueprint-core-1.4.2
            Reporter: Ancoron Luciferis


I have a blueprint configuration as follows (actually from a third-party application):
{code:xml}
<?xml version="1.0" encoding="UTF-8"?>
<blueprint xmlns="http://www.osgi.org/xmlns/blueprint/v1.0.0"
           xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
           xmlns:jpa="http://aries.apache.org/xmlns/jpa/v1.0.0"
           xmlns:tx="http://aries.apache.org/xmlns/transactions/v1.0.0"
           xsi:schemaLocation="
           http://www.osgi.org/xmlns/blueprint/v1.0.0 http://www.osgi.org/xmlns/blueprint/v1.0.0/blueprint.xsd
           http://aries.apache.org/xmlns/jpa/v1.0.0 http://aries.apache.org/xmlns/jpa/v1.0.0
           http://aries.apache.org/xmlns/transactions/v1.0.0 http://aries.apache.org/xmlns/transactions/v1.0.0">

    <bean id="meterDaoBean" class="com.third.party.impl.dao.jpa.JpaMeterDao">
        <jpa:context unitname="MeterUnit" property="entityManager" />
    </bean>

    <reference id="securityService" interface="com.third.party.api.SecurityService" availability="optional"/>

    <bean id="secureMeterDaoBean" class="com.third.party.impl.dao.secure.SecureMeterDao">
        <property name="dao" ref="meterDaoBean" />
        <property name="securityService" ref="securityService" />
    </bean>

    <bean id="meterBean" class="com.third.party.impl.MeterServiceImpl">
        <tx:transaction method="*" value="Required" />

        <property name="meterDao" ref="secureMeterDaoBean" />
    </bean>

    <service ref="meterBean" interface="com.third.party.api.MeterService"/>

</blueprint>
{code}

...and the (for this issue relevant) class definitions look as follows:
{code}
public interface CrudDao<T> {
}

public abstract class SecureDao<T, R extends CrudDao<T>> implements CrudDao<T> {
    protected R dao;

    // ...

    public void setDao(R dao) {
        this.dao = dao;
    }
}

public interface MeterDao extends CrudDao<MeterEntity> {
}

public class JpaMeterDao extends JpaCrudDao<MeterEntity> implements MeterDao {
}

public class SecureMeterDao extends SecureDao<MeterEntity, MeterDao> implements MeterDao {

    // ...

    public MeterEntity get(String id) {
        // some security stuff...
        dao.get(id);
    }
}
{code}

\\
...now with that usage of generics the proxy that gets created for the "dao" member in the {{SecureMeterDao}} bean instance only implements {{CrudDao}}, but not {{MeterDao}}.

So, although the initial blueprint setup of beans and services is fine, any call traveling through the {{SecureMeterDao}} results in a {{ClassCastException}}:
{noformat}
java.lang.ClassCastException: Proxyf427f861_7a7d_41e8_98c7_a09aea99f756 cannot be cast to com.third.party.impl.dao.MeterDao
	at com.third.party.impl.dao.secure.SecureMeterDao.get(SecureMeterDao.java:47)
	at com.third.party.impl.MeterServiceImpl.get(MeterServiceImpl.java:96)
	at Proxy8bef53d7_0df3_4724_a67c_fb296af2aee2.get(Unknown Source)
	at Proxya8f9ae87_fa39_42ae_bf11_baa82efa76cc.get(Unknown Source)
	...
{noformat}




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