Unable to use Repository class of spring data jpa

Question

I'm developing multiple-jobs-in-quartz-spring-example which is combination of Spring + Quartz + Spring Data JPA. I'm looking to developed a code which will run in 5 sec, it will hit to DB and fetches a records from DB. I almost close to make it working but I see small problem. In my JobA.class, I don't get an instance of CustomerRepository.java why ? Its always null and thats why code unable to hit to DB. Please guide how to solve this issue?

Source code at :http://www.github.com/test512/multiple-jobs-in-quartz-spring-example.gi‌​t.

JobA.java

@Service
public class JobA extends QuartzJobBean {

    private CustomerRepository customerRepository = null;

    @Autowired
    public JobA(CustomerRepository customerRepository) {
        this.customerRepository = customerRepository;
    }
    public JobA() { }

    @Override
    protected void executeInternal(JobExecutionContext executionContext) throws JobExecutionException {
        System.out.println("~~~~~~~ Job A is runing ~~~~~~~~");
        Trigger trigger = executionContext.getTrigger();
        System.out.println(trigger.getPreviousFireTime());
        System.out.println(trigger.getNextFireTime());
        getCustomerList();
    }

    private List<Customer> getCustomerList(){
        List<Customer> customers = customerRepository.findAll();
        for (Customer customer : customers) {
            System.out.println("------------------------------");
            System.out.println("ID : "+customer.getId());
            System.out.println("NAME : "+customer.getName());
            System.out.println("STATUS : "+customer.getStatus());
        }
        return customers;
    }
}

Customer.java

@Entity
@Table(name="customer")
public class Customer {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name="ID")
    private Long id;

    @Column(name="NAME")
    private String name;

    @Column(name="STATUS")
    private String status;


    public long getId() {
        return id;
    }
    public void setId(long id) {
        this.id = id;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public String getStatus() {
        return status;
    }
    public void setStatus(String status) {
        this.status = status;
    }
}

CustomerRepository.java

public interface CustomerRepository extends JpaRepository<Customer, Long>{

}

dataSourceContext.xml

<?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:jdbc="http://www.springframework.org/schema/jdbc"
    xmlns:context="http://www.springframework.org/schema/context"
    xsi:schemaLocation="
        http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd
        http://camel.apache.org/schema/spring http://camel.apache.org/schema/spring/camel-spring.xsd
        http://www.springframework.org/schema/jdbc http://www.springframework.org/schema/jdbc/spring-jdbc.xsd">

    <context:property-placeholder location="classpath:database.properties"/>

    <!-- <jdbc:initialize-database data-source="dataSource" enabled="true">
        <jdbc:script location="classpath:db-schema.sql" />
        <jdbc:script location="classpath:db-test-data.sql" />
    </jdbc:initialize-database> -->

    <bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
        <property name="driverClassName" value="${mysql.driver.class.name}" />
        <property name="url" value="${mysql.url}" />
        <property name="username" value="${mysql.username}" />
        <property name="password" value="${mysql.username}" />
    </bean>

    <bean id="jpaVendorAdapter" class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter">
        <property name="showSql" value="true"/>
        <property name="generateDdl" value="true"/>
        <property name="database" value="MYSQL"/>
    </bean>

    <bean id="entityManagerFactory" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
        <property name="dataSource" ref="dataSource"/>
        <property name="jpaVendorAdapter" ref="jpaVendorAdapter"/>
        <!-- spring based scanning for entity classes-->
        <property name="packagesToScan" value="com.mkyong.*"/>
    </bean>

    <bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager"/>
</beans>

Spring-Quartz.xml

<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:jpa="http://www.springframework.org/schema/data/jpa"
    xmlns:repository="http://www.springframework.org/schema/data/repository"
    xmlns:context="http://www.springframework.org/schema/context"
    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd
        http://www.springframework.org/schema/data/jpa http://www.springframework.org/schema/data/jpa/spring-jpa.xsd
        http://www.springframework.org/schema/data/repository http://www.springframework.org/schema/data/repository/spring-repository.xsd">

    <import resource="classpath:dataSourceContext.xml"/>

    <jpa:repositories base-package="com.mkyong.repository" />
    <context:component-scan base-package="com.mkyong.*" />
    <context:annotation-config />

    <bean id="jobA" class="com.mkyong.job.JobA" />
    <bean id="jobB" class="com.mkyong.job.JobB" />
    <bean id="jobC" class="com.mkyong.job.JobC" />
    <bean id="autowiredA" class="com.mkyong.job.JobASpringBeanJobFactory" />

    <!-- ~~~~~~~~~ Quartz Job ~~~~~~~~~~ -->
    <bean name="JobA" class="org.springframework.scheduling.quartz.JobDetailFactoryBean">
        <property name="jobClass" value="com.mkyong.job.JobA" />
    </bean>

    <bean name="JobB" class="org.springframework.scheduling.quartz.JobDetailFactoryBean">
        <property name="jobClass" value="com.mkyong.job.JobB" />
    </bean>

    <bean name="JobC" class="org.springframework.scheduling.quartz.JobDetailFactoryBean">
        <property name="jobClass" value="com.mkyong.job.JobC" />
    </bean>

    <!-- ~~~~~~~~~~~ Cron Trigger, run every 5 seconds ~~~~~~~~~~~~~ -->
    <bean id="cronTriggerJobA" class="org.springframework.scheduling.quartz.CronTriggerFactoryBean">
        <property name="jobDetail" ref="JobA" />
        <property name="cronExpression" value="0/5 * * * * ?" />
    </bean>

    <bean id="cronTriggerJobB" class="org.springframework.scheduling.quartz.CronTriggerFactoryBean">
        <property name="jobDetail" ref="JobB" />
        <property name="cronExpression" value="0/5 * * * * ?" />
    </bean>

    <bean id="cronTriggerJobC" class="org.springframework.scheduling.quartz.CronTriggerFactoryBean">
        <property name="jobDetail" ref="JobC" />
        <property name="cronExpression" value="0/5 * * * * ?" />
    </bean>

    <!-- ~~~~~~~~~~~~~~~~  Scheduler bean Factory   ~~~~~~~~~~~~~~~~ -->
    <bean class="org.springframework.scheduling.quartz.SchedulerFactoryBean">
    <property name="jobFactory" ref="autowiredA"/> 
        <property name="triggers">
            <list>
                <ref bean="cronTriggerJobA" />
                <!-- <ref bean="cronTriggerJobB" />
                <ref bean="cronTriggerJobC" /> -->
            </list>
        </property>
    </bean>
</beans>

JobASpringBeanJobFactory.java

public class JobASpringBeanJobFactory extends SpringBeanJobFactory implements ApplicationContextAware {

    private transient AutowireCapableBeanFactory beanFactory;

    @Override
    public void setApplicationContext(final ApplicationContext context) {
        beanFactory = context.getAutowireCapableBeanFactory();
    }

    @Override
    protected Object createJobInstance(final TriggerFiredBundle bundle) throws Exception {
        final Object job = super.createJobInstance(bundle);
        beanFactory.autowireBean(job);
        return job;
    }
}

App.java

public class App {
    public static void main(String[] args) throws Exception {
        ApplicationContext context = new ClassPathXmlApplicationContext("Spring-Quartz.xml");
    }
}

Answer 1

Going through the following link http://codrspace.com/Khovansa/spring-quartz-with-a-database/ should help.

Quoting from the above link,

Quartz creates a new job instance on each invocation. It means that Quartz jobs are not regular Spring beans and we can't expect the Spring magic to take an effect automatically (and Spring's 'JobDetailFactoryBean' is not smart enough to do it for us). So we'll have to implement our own job factory that would overwrite the default SpringBeanJobFactory.

So you need to have a custom SpringBeanJobFactory by extending SpringBeanJobFactory & implementing ApplicationContextAware and finally invoke beanFactory.autowireBean(job)

Answer 2

Lets open the discussion here now. And expect all experts guidance/ help here.

In the above example, I modified JobA.java class to get an instance of CustomerRepository repository instance using Constructor injection like below:

@Service
public class JobA extends QuartzJobBean {

    private CustomerRepository customerRepository = null;

    @Autowired
    public JobA(CustomerRepository customerRepository) {
        this.customerRepository = customerRepository;
        getCustomerList();
    }
    public JobA() { }

    @Override
    protected void executeInternal(JobExecutionContext arg0) throws JobExecutionException {
        System.out.println("~~~~~~~ Job A is runing ~~~~~~~~");
    }

    private List<Customer> getCustomerList(){
        List<Customer> customers = customerRepository.findAll();
        for (Customer customer : customers) {
            System.out.println("------------------------------");
            System.out.println("ID : "+customer.getId());
            System.out.println("NAME : "+customer.getName());
            System.out.println("STATUS : "+customer.getStatus());
        }
        return customers;
    }
}

But the problem is that when we use customerRepository instance in the executeInternal() method, it nullify it why ? Why ? If somehow instance wont get nullify we are done !!!!