javaapi.md

##SJS Java Api

The Java API in the Spark Job Server is designed to be a more Java friendly API for users to run Spark Jobs inside of SJS.

There are a few differences between this API and the standard one.

• The API is entirely Java based
• Type safety is done via generics instead of type aliases
• Requires it's own set of Context factories specific to Java (very important)

###Basic Example

public class JavaHelloWorldJob implements JSparkJob<String> {

    public String run(JavaSparkContext sc, JobEnvironment runtime, Config data) {
        return "Hi!";
    }

    public Config verify(JavaSparkContext sc, JobEnvironment runtime, Config config) {
        return ConfigFactory.empty();
    }
}

Full File Here

This example does nothing Spark based, but gives an idea of the difference in structure. In order to run a job written like this, the user MUST use the JavaSparkContextFactory. This context is configured the same as any of the Context factories in the Scala API. In addition, there are context types for all Java related jobs. In the Java API, there are both context factories and interfaces that must be used for each kind of job. For instance the JSparkJob uses the JavaSparkContextFactory.

###Additional Context and Job Types

• JavaSqlContextFactory for SQLContext Jobs with JSqlJob
• JavaStreamingContextFactory for StreamingContext jobs with JStreamingJob
• JavaHiveContextFactory for HiveContext jobs with JHiveJob

NOTE: If you do not use the correct context, the jobs will probably not run correctly, it is imperative you configure jobs correctly.