Spring Batch - A job instance already exists: JobInstanceAlreadyCompleteException

Question

I wrote an easy scheduler included in my Spring Application. I run my local server and after few seconds, in class Importer, checker.start() is being invoked each 5 seconds as how I configured in config file.

After that, this method invokes Job with JobLauncher and here I have got an error.

org.springframework.batch.core.repository.JobInstanceAlreadyCompleteException: A job instance already exists and is complete for p arameters={}. If you want to run this job again, change the parameters.

I found a solution how to fix it using annotation but I want to keep it this way.

Thank you in advance

public class Importer {

    private Checker checker;

    public Importer() {
    }

    public void myMethod() {
        try {
            checker.start(); 
        } catch (ClientProtocolException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

with .xml file:

<bean id="schedulerTask"
    class="org.springframework.scheduling.timer.MethodInvokingTimerTaskFactoryBean">
    <property name="targetObject" ref="fileimport" />
    <property name="targetMethod" value="myMethod" />
</bean>

<bean id="fileimport" />
    <property name="targetMethod" value" class="com...Importer">
    <property name="checker">
        <bean id="checker" class="com...Checker">

        </bean>
    </property>
</bean>

<bean id="scheduledTask" class="org.springframework.scheduling.timer.ScheduledTimerTask">
    <property name="timerTask" ref="schedulerTask" />
    <property name="delay" value="${xyz.startdelay}" />
    <property name="period" value="${xyz.checkinterval}" />
</bean>

<bean class="org.springframework.scheduling.timer.TimerFactoryBean">
    <property name="scheduledTimerTasks">
        <list>
            <ref local="scheduledTask" />
        </list>
    </property>
</bean>

And property file:

xyz.checkinterval=5000

xyz.startdelay=0

In class Checker I have got the method:

static ConfigurableApplicationContext applicationContext = new ClassPathXmlApplicationContext("/simplefile-context.xml");
Job job = (Job) applicationContext.getBean("fileBatch");
JobLauncher launcher = (JobLauncher) applicationContext.getBean("jobLauncher");
public void start() throws ClientProtocolException, IOException {
    // ...
    try {
        launcher.run(job, new JobParameters());
        } catch (Exception e) {
        e.printStackTrace();
    }
}

and my "simplefile-context.xml" file looks like this:

<bean id="jobRepository" class="org.springframework.batch.core.repository.support.MapJobRepositoryFactoryBean">
    <property name="transactionManager" ref="transactionManager"/>
</bean>

<!-- bean for lauching the job -->
<bean id="jobLauncher" class="org.springframework.batch.core.launch.support.SimpleJobLauncher">
    <property name="jobRepository" ref="jobRepository" />
</bean>

<task:executor id="taskExecutor" pool-size="100" />

<!--                                   -->
<!--                JOBS               -->
<!--                                   -->
<batch:job id="fileBatch" restartable="true">
    <batch:step id="readLines" >
        <batch:tasklet task-executor="taskExecutor" >
            <batch:chunk reader="fileReader" writer="fooWriter" commit-interval="100" />
        </batch:tasklet>
    </batch:step>
</batch:job>

<bean id="fileReader" class="org.springframework.batch.item.file.FlatFileItemReader">
    <property name="linesToSkip" value="1"/>
    <property name="resource" value="file:./src/main/resources/sample.csv" />
    <property name="lineMapper" ref="lineMapper" />
</bean>

<bean id="lineMapper" class="org.springframework.batch.item.file.mapping.DefaultLineMapper">
    <property name="lineTokenizer" ref="lineTokenizer"/>
    <property name="fieldSetMapper" ref="fieldsetEntityMapper"/>
</bean>

<bean id="lineTokenizer" class="org.springframework.batch.item.file.transform.DelimitedLineTokenizer">
    <property name="delimiter" value=";" />
    <property name="names" value="field1,field2,field3,field4,field5,field6,field7" />
    <property name="strict" value="false"/>
</bean>

<bean id="fieldsetEntityMapper" class="org.springframework.batch.item.file.mapping.BeanWrapperFieldSetMapper">
    <property name="targetType" value="com...model.ModelObject"/>
    <property name="customEditors">
        <map>
            <entry key="java.lang.Double">
                <bean class="org.springframework.beans.propertyeditors.CustomNumberEditor">
                    <constructor-arg index="0" value="java.lang.Double"/>
                    <constructor-arg index="1" value="true"/>
                </bean>
            </entry>
        </map>
    </property>
</bean>

<bean id="fooWriter" class="com...springbatch.writer.FooWriter" />

Answer 1

With your current setup you will only be able to launch the job only once.

    launcher.run(job, new JobParameters());

The job is unique identified by its id together with the parameters. Currently there is no way to make a distinction based on the parameters. Instead of adding new JobParameters() use the JobParamtersBuilderBuilder and add the current date and time.

JobParametersBuilder builder = new JobParametersBuilder();
builder.addDate("date", new Date());
launcher.run(job, builder.toJobParameters());

This will allow you to run the job multiple times.