spring-batch-rest

REST API for Spring Batch based on Spring Boot 2.2 and Spring HATOEAS. It comes with an OpenAPI 3 documentation provided by Springdoc.

Supports Java 8 and above. Tested on OpenJDK 8, 11, and 14.

Features

• Get information on jobs, job executions, and Quartz schedules
• Start job execution (synchronous or asynchronous) with optional job property overrides. The job properties can either be obtained via a custom API or via standard Spring Batch job parameters, accessible from step-scoped beans.

Live Demo

Check out the live demo of this project's Swagger UI. This demo is automatically updated whenever the repo's master branch changes. Please note that it may take up to 30s for this Heroku app to perform a cold start after it has not been used for a while.

Here's how to run a sample job:

• Click on Spring Batch Job Executions, then on POST. Now click on Try it Out on the right-hand side. Replace the contents of the Example Value input field with {"name": "personJob"} and press Execute.
• The job has now been triggered. When it completes, you'll get a response body similar to:

{
  "jobExecution": {
    "id": 1,
    "jobId": 1,
    "jobName": "personJob",
    "startTime": "2018-12-23T18:19:13.185",
    "endTime": "2018-12-23T18:19:13.223",
    "exitCode": "COMPLETED",
    "exitDescription": "",
    "status": "COMPLETED",
    "exceptions": []
  },
  "_links": {
    "self": {
      "href": "https://spring-batch-rest.herokuapp.com/jobExecutions/1"
    }
  }
}

• You can now view this and other recently completed jobs via the job execution overview:

{
  "_embedded": {
  "jobExecutionResourceList": [
    {
    "jobExecution": {
      "id": 1,
      "jobId": 1,
      "jobName": "personJob",
...

Getting Started

To integrate the REST API in your Spring Boot project, first ensure you have an entry point to your application such as

@SpringBootApplication
public class SpringBootApp {
    public static void main(String[] args) {
        SpringApplication.run(SpringBootApp.class, args);
    }
}

Then, simply add one of the following two dependencies to your project:

Core API

The spring-batch-rest-api dependency comes with jobs and jobExecutions REST endpoints. It is recommended if you don't require Quartz for scheduling your jobs.

Maven:

<dependency>
    <groupId>com.github.chrisgleissner</groupId>
    <artifactId>spring-batch-rest-api</artifactId>
    <version>1.5.1</version>
</dependency>

Gradle:

implementation 'com.github.chrisgleissner:spring-batch-rest-api:1.5.1'

Quartz API

The spring-batch-rest-quartz-api dependency includes everything above and and additionally exposes Quartz schedules via the jobDetails REST endpoint.

Maven:

<dependency>
    <groupId>com.github.chrisgleissner</groupId>
    <artifactId>spring-batch-rest-quartz-api</artifactId>
    <version>1.5.1</version>
</dependency>

Gradle:

implementation 'com.github.chrisgleissner:spring-batch-rest-quartz-api:1.5.1'

See it in Action

To see spring-batch-rest-api in action, run

mvn install -Dmaven.test.skip; java -jar example/api/target/*.jar

For spring-batch-rest-quartz-api, run

mvn install -Dmaven.test.skip; java -jar example/quartz-api/target/*.jar

Once it's up, check the Swagger REST API docs at http://localhost:8080/swagger-ui.html.

REST Endpoints

The following REST endpoints are available:

Jobs

Job Executions

Request Parameters for GET /jobExecutions

Examples

Quartz Schedules

As mentioned above, these endpoints are only exposed if you're using the spring-batch-rest-quartz-api dependency:

Error Handling

Where possible, subclasses of the Spring Batch JobExecutionException are mapped to an appropriate HTTP status code and the response body contains further details.

For example, trying to start a nonexistent job results in a response with a 404 status code and the following response body:

{
  "status": "404 NOT_FOUND",
  "message": "No job configuration with the name [foo] was registered",
  "exception": "NoSuchJobException",
  "detail": "Failed to start job 'foo' with JobConfig(name=foo, properties={foo=baz10}, asynchronous=false). Reason: No job configuration with the name [foo] was registered"
}

Configuration

The default behaviour of the REST API can be tweaked via several Spring properties which can be placed in application.properties.

Job Execution Caching

com.github.chrisgleissner.springbatchrest.jobExecutionCacheSize (default: 100)

For performance reasons, /jobExecutions queries are performed against an in-memory cache of recent job executions. If the limitPerJob request parameter is larger than the value of this property, the cache is bypassed and the Spring Batch JobExplorer is used instead.

Large jobExecutionCacheSize values will result in increased heap use, but small values combined with large limitSize request parameters will cause increased REST query latencies. Thus, if you increase this property value, you may also want to increase your heap size.

The cache only contains job executions since the Spring context creation, ie. it is not warmed up from the JobExplorer and the DB this may rely on. If you want to be able to query job executions that were performed earlier, eg. during a prior JVM execution, you may want to disable caching. To do so, simply set the property to 0.

Repeated Job Execution

com.github.chrisgleissner.springbatchrest.addUniqueJobParameter (default: true)

Spring Batch prevents repeated invocations of a job unless you use different properties (aka job parameters) each time. To bypass this, a unique property (ie. a random UUID) is added to each job invocation. You can disable this by setting the property to false.

Disable Spring Batch REST API REST Endpoints

com.github.chrisgleissner.springbatchrest.enabled=false (default: true)

Useful if you only want to expose the REST API in certain environments.

Disable Swagger UI

springdoc.swagger-ui.enabled=false (default: true)

See https://github.com/springdoc/springdoc-openapi for further config options.

Disable Custom Exception Handling

com.github.chrisgleissner.springbatchrest.controllerAdvice=false (default: true)

This disables the global exception handling via com.github.chrisgleissner.springbatchrest.api.core.jobexecution.ResponseExceptionHandler.

Job Property Overrides

Properties can be overridden when starting a job via REST. You can then access these overrides in one of the following ways.

@Value

Annotate your Spring bean method with @StepScope and use the @Value annotation on a method parameter to specify the desired job parameter name.

Please note that this approach won't transparently fall back to Spring environment properties. Thus, if this is desired, you should manually check if a job parameter is null and in this case return it from the Spring Environment instance.

Example:

@Bean @StepScope  
ItemWriter<Object> writer(@Value("#{jobParameters['sampleProperty']}") String sampleProperty) {
    // ... 
}

PropertyResolver

When using AdhocStarter, you can create a Job using a JobBuilder and pass in a Consumer<PropertyResolver>.

Properties looked up from this PropertyResolver transparently fall back to the Spring environment if properties can't be found in the job parameters.

Example:

Job job = jobBuilder.createJob("sampleJob", propertyResolver -> {
    String propertyValue = propertyResolver.getProperty("sampleProperty");
    // ...
});

JobProperties

In case you don't execute the same job concurrently, you may also look up properties from the JobProperties singleton.

Properties looked up from this singleton transparently fall back to the Spring environment if properties can't be found in the job parameters.

This approach is deprecated as it doesn't work with concurrent execution of the same job. Therefore, it is recommended to use one of the other approaches.

Example:

@Bean
ItemWriter<Object> writer() {
    return new ItemWriter<Object>() {
        @Override
        public void write(List<?> items) throws Exception {
           String sampleProperty = JobPropertyResolvers.JobProperties.of("sampleJob").getProperty("sampleProperty");
           // ...
        }
    }
}

Utilities

The util module contains code for registering, starting and scheduling jobs:

JobBuilder builds a simple job based on a Runnable:

Job job = jobBuilder.createJob("jobName", () -> System.out.println("Running job"));

AdHocScheduler registers and triggers a job using a Quartz CRON trigger. This can be performed at run-time rather than Spring wiring time which allows for simplified set-up of a large number of jobs that only differ slightly:

adHocScheduler.schedule("jobName", job, "0/30 * * * * ?");

AdHocStarter is similar to AdHocScheduler, but used for immediately starting a job:

adHocStarter.start(job);