CODEWITHSUNDEEP
javaspringnullpointerexception
l0r3nz4cc10
l0r3nz4cc10

Reputation: 1283

NullpointerException Dao in bean

in my web application developped with GWT, Hibernate ans Spring, I encounter when setting the jobClass bean in the application-context.xml file.

I get a NullPointerException at runtime, with absenceDao being null:

Here is my Java class :


public class ExampleJob extends QuartzJobBean {
    private AbsenceDao absenceDao; 
    @Override
    protected void executeInternal(JobExecutionContext context)
    throws JobExecutionException {
        List untreatedDemands = new ArrayList();
        untreatedDemands = absenceDao.getDemandsAskedNotValidated();
    }
    public AbsenceDao getAbsenceDao() {
        return absenceDao;
    }
    public void setAbsenceDao(AbsenceDao absenceDao) {
        this.absenceDao = absenceDao;
    }
}

and here is my application-context.xml :

classpath:internal.properties 

<!-- Configuration du crontrigger -->
<bean id="schedulerFactory" class="org.springframework.scheduling.quartz.SchedulerFactoryBean">
    <property name="triggers">
        <list>
            <ref bean="cronTrigger" />
        </list>
    </property>
</bean>
<bean id="cronTrigger" class="org.springframework.scheduling.quartz.CronTriggerBean">
    <property name="jobDetail">
        <ref local="exampleJob1" />
    </property>

    <property name="cronExpression">
        <util:constant static-field="fr.web.utils.APP_VAR.CRON_EXPRESSION" />
    </property>
</bean>

<bean id="jobClass" class="fr.web.utils.ExampleJob">
    <property name="absenceDao" ref="absenceDao"/>
</bean>

<bean id="exampleJob1" class="org.springframework.scheduling.quartz.JobDetailBean">
    <property name="jobClass" value="fr.web.utils.ExampleJob" />
    <property name="jobDataAsMap">
        <map>
            <entry key="timeout" value="5" />
        </map>
    </property>
</bean>

<!-- Bean containing all the properties of the application -->
<bean class="fr.web.utils.ApplicationProperties" id="applicationProperties" lazy-init="true" scope="singleton">
    <constructor-arg index="0" value="classpath:internal.properties"/>
</bean>

<!-- Bean DAO -->
<bean abstract="true" id="abstractDao">
    <property name="sessionFactory" ref="sessionFactory"/>
</bean>
<bean class="fr.web.dao.AbsenceDao" id="absenceDao" parent="abstractDao"/>

</bean>

I thought setting a property refering the Dao in the jobClass bean was enough, but obviously, I'm wrong.

Edit : if I set the Dao property in the exampleJob1 bean, I get this error at runtime :


Error 500 Error creating bean with name 'schedulerFactory' defined in class path resource [application-context.xml]:
Cannot resolve reference to bean 'cronTrigger' while setting bean property 'triggers' with key [0];

nested exception is org.springframework.beans.factory.BeanCreationException:
Error creating bean with name 'cronTrigger' defined in class path resource [application-context.xml]:
Cannot resolve reference to bean 'exampleJob1' while setting bean property 'jobDetail';

nested exception is org.springframework.beans.factory.BeanCreationException:
Error creating bean with name 'exampleJob1' defined in class path resource [application-context.xml]:
Error setting property values;

nested exception is org.springframework.beans.NotWritablePropertyException:
Invalid property 'absenceDao' of bean class [org.springframework.scheduling.quartz.JobDetailBean]:
Bean property 'absenceDao' is not writable or has an invalid setter method.

Does the parameter type of the setter match the return type of the getter?

Upvotes: 0

Views: 1809

Answers (1)

duffymo
duffymo

Reputation: 308743

No, you have to set DAO property in the exampleJob1 bean configuration to refer to the DAO bean.

It's necessary to have the bean definitions in the app config, but not sufficient. You also have to tell the Spring bean factory how to wire them together.

You might add the @Autowired annotation to the Java class. That would take care of it, as long as you had annotations turned on.

Upvotes: 2

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