= batch-processing: Chunk oriented Batch 1.0 processing
:author: Rafael Benevides
:productName: WildFly
:productNameFull: WildFly Application Server
:jbossHomeName: WILDFLY_HOME
:productVersion: 12
:buildRequirements: Java 8.0 (Java SDK 1.8) or later and Maven 3.3.1 or later
include::../shared-doc/attributes.adoc[]

:level: Intermediate
:technologies: CDI, Batch 1.0, JSF
:source: {githubRepoUrl}

[abstract]
The `batch-processing` quickstart shows how to use chunk oriented batch jobs to import a file to a database.

:standalone-server-type: default
:archiveType: war

== What is it?

This quickstart simulates a file importation using batch jobs. To make it easy, this quickstart offers the user a way to generate files. The generated file can have its name and the number of records customized. The user can also specify if the file contains an error or not.

The job contains two tasks:

. It imports the file using a chunk oriented approach.

* The chunk size is set to `3`.
* The `RecordsReader` is responsible for parsing the file and create an instance of `Contact`.
* The `ContactsFormatter` applies the proper case to the contact name and it also applies a mask to the phone number.
* Finally, `ContactsPersister` sends the contact instance to the database.

. It logs the number of records imported.

The database schema defines that the column for name is unique. For that reason, any attempt to persist a duplicate value will throw an exception. On the second attempt to run the job, the `ChunkCheckpoint` provides information to skip the contacts that were already persisted.

//*************************************************
// Add notes about use in a production environment.
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// == Considerations for Use in a Production Environment
:uses-h2:
:uses-ds-xml:
include::../shared-doc/development-shortcuts.adoc[leveloffset=+1]

//*************************************************
// Add System Requirements
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// == System Requirements
include::../shared-doc/system-requirements.adoc[leveloffset=+1]

//*************************************************
// Add Use of JBoss Home Name
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// == Use of {jbossHomeName}
include::../shared-doc/use-of-jboss-home-name.adoc[leveloffset=+1]

//*************************************************
// Start the server with the default profile
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// == Start the {productName} Standalone Server
include::../shared-doc/start-the-standalone-server.adoc[leveloffset=+1]

//*************************************************
// Build and deploy the quickstart WAR
//*************************************************
// == Build and Deploy the Quickstart
include::../shared-doc/build-and-deploy-the-quickstart.adoc[leveloffset=+1]

== Access the Application

Access the running application in a browser at the following URL: http://localhost:8080/{artifactId}/

You are presented with a simple form that allows you to generate sample files to be imported.

=== Usage 1: Import the file without any errors

. Click on *Generate a new file and start import job* button. This generates a new file with 10 unique records to be imported. The import job starts after the file is generated.

. A table is displayed containing information about the task that was started. Click on the *Update jobs list* button and verify that the job was completed.

. Investigate the console output. It shows that files with 10 records were processed, 3 records at a time.
+
[source,options="nowrap"]
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INFO  [org.jboss.as.quickstarts.batch.controller.BatchController] (default task-3) Starting to generate 10 in file /var/folders/j8/63sgdmbn5tqdkyw0tz6df53r0000gn/T/temp-file.txt
INFO  [org.jboss.as.quickstarts.batch.controller.BatchController] (default task-3) File generated at /var/folders/j8/63sgdmbn5tqdkyw0tz6df53r0000gn/T/temp-file.txt
INFO  [org.jboss.as.quickstarts.batch.job.listener.JobListener] (Batch Thread - 1) Job import-file - Execution #1 starting.
INFO  [org.jboss.as.quickstarts.batch.job.ContactsPersister] (Batch Thread - 1) No checkpoint detected. Cleaning the Database
INFO  [org.jboss.as.quickstarts.batch.job.ContactsFormatter] (Batch Thread - 1) Register #1 - Changing name ZIqYKITxiM -> Ziqykitxim | phone  978913851 -> (978)-913-851
INFO  [org.jboss.as.quickstarts.batch.job.ContactsFormatter] (Batch Thread - 1) Register #2 - Changing name JbHjnaThps -> Jbhjnathps | phone  095108018 -> (095)-108-018
INFO  [org.jboss.as.quickstarts.batch.job.ContactsFormatter] (Batch Thread - 1) Register #3 - Changing name FJTlXRtCdR -> Fjtlxrtcdr | phone  286847939 -> (286)-847-939
INFO  [org.jboss.as.quickstarts.batch.job.listener.PersistListener] (Batch Thread - 1) Preparing to persist 3 contacts
INFO  [org.jboss.as.quickstarts.batch.job.listener.PersistListener] (Batch Thread - 1) Persisting 3 contacts
INFO  [org.jboss.as.quickstarts.batch.job.ContactsFormatter] (Batch Thread - 1) Register #4 - Changing name mlmBABWzfL -> Mlmbabwzfl | phone  744478648 -> (744)-478-648
INFO  [org.jboss.as.quickstarts.batch.job.ContactsFormatter] (Batch Thread - 1) Register #5 - Changing name jVlTYiBRMP -> Jvltyibrmp | phone  135063841 -> (135)-063-841
INFO  [org.jboss.as.quickstarts.batch.job.ContactsFormatter] (Batch Thread - 1) Register #6 - Changing name DwEFbSjfQE -> Dwefbsjfqe | phone  404572175 -> (404)-572-175
INFO  [org.jboss.as.quickstarts.batch.job.listener.PersistListener] (Batch Thread - 1) Preparing to persist 3 contacts
INFO  [org.jboss.as.quickstarts.batch.job.listener.PersistListener] (Batch Thread - 1) Persisting 3 contacts
INFO  [org.jboss.as.quickstarts.batch.job.ContactsFormatter] (Batch Thread - 1) Register #7 - Changing name niDXWwGJuQ -> Nidxwwgjuq | phone  949448390 -> (949)-448-390
INFO  [org.jboss.as.quickstarts.batch.job.ContactsFormatter] (Batch Thread - 1) Register #8 - Changing name VZBArfowSe -> Vzbarfowse | phone  902370961 -> (902)-370-961
INFO  [org.jboss.as.quickstarts.batch.job.ContactsFormatter] (Batch Thread - 1) Register #9 - Changing name aSpyWCWwje -> Aspywcwwje | phone  246977695 -> (246)-977-695
INFO  [org.jboss.as.quickstarts.batch.job.listener.PersistListener] (Batch Thread - 1) Preparing to persist 3 contacts
INFO  [org.jboss.as.quickstarts.batch.job.listener.PersistListener] (Batch Thread - 1) Persisting 3 contacts
INFO  [org.jboss.as.quickstarts.batch.job.ContactsFormatter] (Batch Thread - 1) Register #10 - Changing name TofTfbRBzI -> Toftfbrbzi | phone  868339088 -> (868)-339-088
INFO  [org.jboss.as.quickstarts.batch.job.listener.PersistListener] (Batch Thread - 1) Preparing to persist 1 contacts
INFO  [org.jboss.as.quickstarts.batch.job.listener.PersistListener] (Batch Thread - 1) Persisting 1 contacts
INFO  [org.jboss.as.quickstarts.batch.job.ReportBatchelet] (Batch Thread - 1) Imported 10 to Database
INFO  [org.jboss.as.quickstarts.batch.job.listener.JobListener] (Batch Thread - 1) Job import-file - Execution #1 finished. Status: COMPLETED
----

=== Usage 2: Import an error file and fix it

Now you will simulate a file with duplicate records. This will raise an exception and stop the processing. After that, you will fix the file and continue the importing where it stopped.

. Mark the *Generate a duplicate record* checkbox and click on *Generate a new file and start import job* button. If you click on *Update jobs list* button, you will see that the job failed with the following Exit Status: `Error : org.hibernate.exception.ConstraintViolationException: could not execute statement`. This was caused because the job tried to insert a duplicate record at the Database. You will also see `org.h2.jdbc.JdbcSQLException: Unique index or primary key violation` exception stacktraces in the server log.

. Next, you will fix the file and restart that job execution. Uncheck the *Generate a duplicate record* checkbox and click on *Generate a new file* button. This will generate the file without errors.

. Click on *Restart* button in the last column for that job instance in the *List of Jobs* table. If you click on *Update jobs list* button, you will see that the job was completed.

. Review the server logs and verify that the job started from the last checkpoint.
+
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INFO  [org.jboss.as.quickstarts.batch.job.RecordsReader] (Batch Thread - 3) Skipping to line 3 as marked by previous checkpoint
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. Investigate the console output.
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INFO  [org.jboss.as.quickstarts.batch.job.listener.JobListener] (Batch Thread - 3) Job import-file - Execution #3 starting.
INFO  [org.jboss.as.quickstarts.batch.job.RecordsReader] (Batch Thread - 3) Skipping to line 3 as marked by previous checkpoint
INFO  [org.jboss.as.quickstarts.batch.job.ContactsFormatter] (Batch Thread - 3) Register #4 - Changing name HdeqwzEjbA -> Hdeqwzejba | phone  686417040 -> (686)-417-040
INFO  [org.jboss.as.quickstarts.batch.job.ContactsFormatter] (Batch Thread - 3) Register #5 - Changing name veEEbtpYTJ -> Veeebtpytj | phone  367981821 -> (367)-981-821
INFO  [org.jboss.as.quickstarts.batch.job.ContactsFormatter] (Batch Thread - 3) Register #6 - Changing name bQIKTUyqMW -> Bqiktuyqmw | phone  103363182 -> (103)-363-182
INFO  [org.jboss.as.quickstarts.batch.job.listener.PersistListener] (Batch Thread - 3) Preparing to persist 3 contacts
INFO  [org.jboss.as.quickstarts.batch.job.listener.PersistListener] (Batch Thread - 3) Persisting 3 contacts
INFO  [org.jboss.as.quickstarts.batch.job.ContactsFormatter] (Batch Thread - 3) Register #7 - Changing name KVLIGXhCry -> Kvligxhcry | phone  117327691 -> (117)-327-691
INFO  [org.jboss.as.quickstarts.batch.job.ContactsFormatter] (Batch Thread - 3) Register #8 - Changing name PBAZgernHy -> Pbazgernhy | phone  066203468 -> (066)-203-468
INFO  [org.jboss.as.quickstarts.batch.job.ContactsFormatter] (Batch Thread - 3) Register #9 - Changing name DGtNZdteGB -> Dgtnzdtegb | phone  908779587 -> (908)-779-587
INFO  [org.jboss.as.quickstarts.batch.job.listener.PersistListener] (Batch Thread - 3) Preparing to persist 3 contacts
INFO  [org.jboss.as.quickstarts.batch.job.listener.PersistListener] (Batch Thread - 3) Persisting 3 contacts
INFO  [org.jboss.as.quickstarts.batch.job.ContactsFormatter] (Batch Thread - 3) Register #10 - Changing name mhmIHhZMhv -> Mhmihhzmhv | phone  094518410 -> (094)-518-410
INFO  [org.jboss.as.quickstarts.batch.job.listener.PersistListener] (Batch Thread - 3) Preparing to persist 1 contacts
INFO  [org.jboss.as.quickstarts.batch.job.listener.PersistListener] (Batch Thread - 3) Persisting 1 contacts
WARN  [org.jberet] (Batch Thread - 3) JBERET000018: Could not find the original step execution to restart.  Current step execution id: 0, step name: reportBatchelet
INFO  [org.jboss.as.quickstarts.batch.job.ReportBatchelet] (Batch Thread - 3) Imported 10 to Database
INFO  [org.jboss.as.quickstarts.batch.job.listener.JobListener] (Batch Thread - 3) Job import-file - Execution #3 finished. Status: COMPLETED
----

=== Usage 3: Import an error file and do not fix the errors

. Check the *Generate a duplicate record* checkbox and click on *Generate a new file ans start import job* button. If you click on *Update jobs list* button, you will see that the job failed with the following Exit Status: `Error : org.hibernate.exception.ConstraintViolationException: could not execute statement`. This was caused because you tried to insert a duplicate record at the Database.

. This time you will not fix the file. Just click on *Restart* button again. If you click on *Update jobs list* button, you will see that the job was marked as `ABANDONED` this time because it was restarted once. Notice that there is a new parameter: `restartedOnce=true`. This behavior was implemented in `JobListener` for demonstration purposes, to prevent a `FAILED` job from being restarted twice.

== Server Log: Expected Warnings and Errors

You will see the following warnings in the server log. You can ignore these warnings.

[source,options="nowrap"]
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WFLYJCA0091: -ds.xml file deployments are deprecated. Support may be removed in a future version.

HHH000431: Unable to determine H2 database version, certain features may not work
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//*************************************************
// Undeploy the quickstart archive
//*************************************************
// == Undeploy the Quickstart
include::../shared-doc/undeploy-the-quickstart.adoc[leveloffset=+1]

//*************************************************
// Add JBoss Developer Studio instructions
//*************************************************
// == Run the Quickstart in Red Hat JBoss Developer Studio or Eclipse
include::../shared-doc/run-the-quickstart-in-jboss-developer-studio.adoc[leveloffset=+1]

//*************************************************
// Deploy the quickstart to OpenShift
//*************************************************
// == Deploy the Quickstart to OpenShift Online
include::../shared-doc/deploy-to-openshift-online.adoc[leveloffset=+1]

//*************************************************
// Add info to debug the application
//*************************************************
// == Debug the Application
include::../shared-doc/debug-the-application.adoc[leveloffset=+1]
