implementing batch processing in java ee 7 2014...batch - javaland 2014 @ivar_grimstad implementing...

Batch - JavaLand 2014 @ivar_grimstad

Implementing Batch Processing in Java EE 7Ivar Grimstad

Ivar Grimstad

About


@ivar_grimstad

batch (plural batches)

The quantity of bread or other baked goods baked at one time.

We made a batch of cookies to take to the party.


Source: http://en.wiktionary.org/wiki/batch

• Batch Applications

• Batch in Java EE 7

• Demo

• Wrap-Up

Content


History


Batch Applications


• Bulk database updates

• Image processing

• Conversions

Common Usages


• No User Interaction

• Utilize Batch Windows

• Repetitive Work

Advantages of Batch Processing


• Training

• Difficult Debugging

• Costly

Disadvantages of Batch Processing


Batch Frameworks

To The Rescue


• Jobs, steps, decision elements, relationships

• Parallel or sequential processing

• State

• Launch, pause and resume

• Error handling

Batch Frameworks


Large Data Volume

Automation

Robustness

Reliability

Performance

Requirements of Batch Applications



Batch Processing in Java EE 7

• Batch Runtime

• Job Specification

• Java API

–Runtime interaction

– Implementation

The Batch Processing Framework


• Start jobs

• Check status of jobs

Batch Runtime


• Steps

• Flows

• Splits

• Decision Elements

Job Specification


Job Specification Language (JSL)


<job>

<listeners>

<listener />

</listeners>

<properties>

<property />

</properties>

<step ...> ... </step>

<step ...> ... </step>

<decision ...> ... </decision>

<flow ...> ... </flow>

<split ...> ... </split>

</job>

Java Batch API (task oriented)


Package Interface Description

javax.batch.api BatchletImplements the business logic of a task-oriented

step.

Java Batch API (chunk oriented)



javax.batch.api.chunk ItemReaderReads items from an input source in a

chunk step.

javax.batch.api.chunk ItemProcessorProcesses input items to obtain output

items in chunk steps.

javax.batch.api.chunk ItemWriter Writes output items in chunk steps.

ItemReader ItemWriterItemProcessor

Chunk Oriented Steps


Item

Dependency Injection


@Dependent

@Named("MyItemReader")

public class MyItemReaderImpl implements ItemReader {

}

<step id="stepA" next="stepB">

<chunk>

<reader ref="MyItemReader"></reader>

...

</chunk>

</step>

Batch Runtime API


@Dependent

@Named("MyItemReader")

public class MyItemReaderImpl implements ItemReader {

@Inject

JobContext jobCtx;

@Inject

StepContext stepCtx;

}

Invocation


jobOperator = BatchRuntime.getJobOperator();

Properties props = new Properties();

props.setProperty("parameter1", "value1");

long execID = jobOperator.start("simplejob", props);

EJB, Servlet, ManagedBean etc.

• No separate packaging needed

• Can be included in any Java EE application

–META-INF/batch-jobs/

–WEB-INF/classes/META-INF/batch-jobs/

Packaging


Monitoring



javax.batch.runtime JobExecutionProvides methods to obtain information

about submitted jobs.

JobExecution jobExec = jobOperator.getJobExection(id);

String status = jobExec.getBatchStatus().toString();

• Design the application

• Create batch artifacts

• Define jobs, steps and execution flow

• Launch batch application

Creating a Java EE Batch Application



DEMO

• Create a simple batchlet

• Create a simple chunk oriented job

• Package in a WAR

• Start jobs from a Servlet

• Schedule jobs from Timer EJB

Demo Steps


Simple Batchlet


Simple Chunk Oriented


• Created a simple batchlet

• Created a simple chunk oriented job

• Packaged application in a WAR

• Started jobs from a Servlet

• Scheduled jobs from Timer EJB

Demo Steps (what we did)



Summary

…but isn’t it?


• Simple and Flexible

• Clear and precise API

• No separate packaging required

• Is a part of Java EE

Summary


https://github.com/ivargrimstad/javaee-batch

Sources


implementing batch processing in java ee 7 2014...batch - javaland 2014 @ivar_grimstad implementing...

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