Dynamic config Spring batch execution time and parameters via database configured parameters - spring-batch

Question

I am a fresh spring batch user, pls help me. Here is my requirement:
I have fulfilled several spring batch jobs with different names. I want to execute these jobs with different job parameters, and I hope these parameters can be configured dynamically in database, so I can add new job execution with different job names and different parameters.
Also, I want to schedule my job execution in different time, and the crontab expression can also be configured.
Maybe the database structure is like:
id
task_name
spring_batch_job_name
cron_expression
Wonder if some guys can guide me. Very thanks!

Answer 1

Here is my job setting entity:
#Entity
#Table(name = "report_tasks_manager", schema = "reconciliation", catalog = "")
public class ReportTasksManager {
private int id;
private String taskDesc;
private String taskName;
// crontab expression
private String cronExpression;
// class name to execute job logic
private String methodName;
private int state;
private Integer conCurrent;
private String reserved1;
private String reserved2;
private String reserved3;
private Timestamp startTime;
private Timestamp endTime;
private Timestamp createTime;
}
I defined a class which implemented Job interface, and the execute() method in this class executes the business logic, like launching a spring batch job:
public class QuartzJobFactory implements Job {
public QuartzJobFactory() {
}
#Override
public void execute(JobExecutionContext jobExecutionContext) throws JobExecutionException {
System.out.println("time ={" + new Date() + "}");
System.out.println("starting job build factory");
ReportTasksManager reportTasksManager = (ReportTasksManager) jobExecutionContext.getMergedJobDataMap().get("scheduleJob");
System.out.println("job name = {" + reportTasksManager.getTaskName() + "}");
}
}
For registering a cron trigger, I defined a rest controller to checkout job parameters in database and configure scheduler
#RestController
#RequestMapping(path = "test")
public class QuartzManager {
private SchedulerFactory schedulerFactory = new StdSchedulerFactory();
#Autowired
private ReportTaskManagerDAO reportTaskManagerDAO;
#GetMapping(value = "schedule")
public void scheduleJob() {
// Read settings from database
List<ReportTasksManager> quartzList = reportTaskManagerDAO.findAll();
if (quartzList.size() > 0) {
quartzList.forEach(reportTasksManager -> {
try {
configQuartz(reportTasksManager, schedulerFactory.getScheduler());
} catch (SchedulerException | ClassNotFoundException e) {
e.printStackTrace();
}
});
}
}
#SuppressWarnings("unchecked")
private void configQuartz(ReportTasksManager reportTasksManager, Scheduler scheduler) throws SchedulerException, ClassNotFoundException {
TriggerKey triggerKey = TriggerKey.triggerKey(reportTasksManager.getTaskName(), Scheduler.DEFAULT_GROUP);
// check if triggers already defined in scheduler
CronTrigger trigger = (CronTrigger) scheduler.getTrigger(triggerKey);
if (null == trigger) {
// not define——new trigger&jobDetail
JobDetail jobDetail =
JobBuilder.newJob((Class<? extends Job>) Class.forName(reportTasksManager.getMethodName()))
.withIdentity(reportTasksManager.getTaskName(), Scheduler.DEFAULT_GROUP)
.build();
jobDetail.getJobDataMap().put("scheduleJob", reportTasksManager);
CronScheduleBuilder scheduleBuilder = CronScheduleBuilder.cronSchedule(reportTasksManager.getCronExpression());
trigger = TriggerBuilder.newTrigger()
.withIdentity(reportTasksManager.getTaskName(), Scheduler.DEFAULT_GROUP)
.withSchedule(scheduleBuilder)
.build();
scheduler.scheduleJob(jobDetail, trigger);
scheduler.start();
} else {
// already defined——update
CronScheduleBuilder scheduleBuilder = CronScheduleBuilder.cronSchedule(reportTasksManager.getCronExpression());
trigger = trigger.getTriggerBuilder()
.withIdentity(triggerKey)
.withSchedule(scheduleBuilder)
.build();
scheduler.rescheduleJob(triggerKey, trigger);
}
}
}

Answer 2

You can use create some Util class( on #PostConstruct) which loads your job config from DB.
For example:
#Entity
public class Configuration{
#Id
private long id;
private String field;
private String value;
// getter and setter
}
#Component
public interface ConfigurationRepo extends JpaRepository<Configuration, Long> {
}
public final class ConfigurationUtil {
private ConfigurationUtil() {
}
private static List<Configuration> defaultConfiguration;
/**
* #return the defaultConfiguration
*/
public static List<Configuration> getDefaultConfiguration() {
return defaultConfiguration;
}
/**
* #param defaultConfiguration the defaultConfiguration to set
*/
public static void setDefaultConfiguration(List<Configuration> defaultConfiguration) {
ConfigurationUtil.defaultConfiguration = defaultConfiguration;
}
public static String getValueByField(String field) {
return defaultConfiguration.stream()
.filter(s -> s.getField()
.equalsIgnoreCase(field))
.findFirst()
.get()
.getValue();
}
}
#Component
public class ConfigurationContextInitializer {
#Autowired
ConfigurationRepo configurationRepo;
#PostConstruct
public void init() {
ConfigurationUtil.setDefaultConfiguration(configurationRepo.findAll());
}
}
//To access DB value
ConfigurationUtil.getValueByField("JOB_NAME"); // depends on your DB key