Setup
Application Contexts
All JSR-352 based jobs within Spring Batch consist of two application contexts. A parent context, that
contains beans related to the infrastructure of Spring Batch such as the JobRepository,
PlatformTransactionManager, etc and a child context that consists of the configuration
of the job to be run. The parent context is defined via the baseContext.xml provided
by the framework. This context may be overridden via the JSR-352-BASE-CONTEXT system
property.
![[Note]](images/note.png) | Note |
|---|---|
The base context is not processed by the JSR-352 processors for things like property injection so no components requiring that additional processing should be configured there. |
Launching a JSR-352 based job
JSR-352 requires a very simple path to executing a batch job. The following code is all that is needed to execute your first batch job:
JobOperator operator = BatchRuntime.getJobOperator();
jobOperator.start("myJob", new Properties());While that is convenient for developers, the devil is in the details. Spring Batch bootstraps a bit of
infrastructure behind the scenes that a developer may want to override. The following is bootstrapped the
first time BatchRuntime.getJobOperator() is called:
| Bean Name | Default Configuration | Notes |
| dataSource | Apache DBCP BasicDataSource with configured values. | By default, HSQLDB is bootstrapped. |
transactionManager
|
org.springframework.jdbc.datasource.DataSourceTransactionManager
| References the dataSource bean defined above. |
| A Datasource initializer |
This is configured to execute the scripts configured via the
batch.drop.script and batch.schema.script properties. By
default, the schema scripts for HSQLDB are executed. This behavior can be disabled via
batch.data.source.init property.
| |
| jobRepository |
A JDBC based SimpleJobRepository.
|
This JobRepository uses the previously mentioned data source and transaction
manager. The schema's table prefix is configurable (defaults to BATCH_) via the
batch.table.prefix property.
|
| jobLauncher |
org.springframework.batch.core.launch.support.SimpleJobLauncher
| Used to launch jobs. |
| batchJobOperator |
org.springframework.batch.core.launch.support.SimpleJobOperator
|
The JsrJobOperator wraps this to provide most of it's functionality.
|
| jobExplorer |
org.springframework.batch.core.explore.support.JobExplorerFactoryBean
|
Used to address lookup functionality provided by the JsrJobOperator.
|
| jobParametersConverter |
org.springframework.batch.core.jsr.JsrJobParametersConverter
|
JSR-352 specific implementation of the JobParametersConverter.
|
| jobRegistry |
org.springframework.batch.core.configuration.support.MapJobRegistry
|
Used by the SimpleJobOperator.
|
| placeholderProperties |
org.springframework.beans.factory.config.PropertyPlaceholderConfigure
|
Loads the properties file batch-${ENVIRONMENT:hsql}.properties to configure
the properties mentioned above. ENVIRONMENT is a System property (defaults to hsql)
that can be used to specify any of the supported databases Spring Batch currently
supports.
|
| Note |
|---|---|
None of the above beans are optional for executing JSR-352 based jobs. All may be overriden to provide customized functionality as needed. |