io.cdap.cdap.api.annotation

Annotation Type Requirements

@Retention(value=RUNTIME)
 @Target(value=TYPE)
public @interface Requirements

Annotates the requirements needed by a plugin to run successfully.

Requirements are case insensitive.

If a plugin is not annotated with Requirements or the annotation datasetTypes() is empty, then it is assumed that the plugin does not have any specific requirements and can run everywhere.

Usage Examples:

• Omitting Requirements: A plugin can choose to not specify any requirement by not specifying a Requirements annotation. In this case the plugin will considered to be capable or run everywhere.

      @Plugin(type = BatchSource.PLUGIN_TYPE)
      @Name("CSVParser")
      public class CSVParser extends BatchSource<byte[], Row, StructuredRecord> {
       ...
       ...
      }
   

• Specifying a particular requirement: If a plugin requires CDAP 'table' dataset then this can be specified as below.

      @Plugin(type = BatchSource.PLUGIN_TYPE)
      @Name("Table")
      @Requirements(datasetTypes = {"table"})
      public class Table extends BatchSource<byte[], Row, StructuredRecord> {
       ...
       ...
      }
   

• Specifying multiple requirements: A plugin can also specify multiple requirements. For example if a plugin needs 'table' and 'keyValueTable' to run this can specified as below.

      @Plugin(type = BatchSource.PLUGIN_TYPE)
      @Name("MultiTable")
      @Requirements(datasetTypes = {"table", "keyValueTable"})
      public class MultiTableSource extends BatchSource<byte[], Row, StructuredRecord> {
       ...
       ...
      }
   

Optional Element Summary

Optional Elements

Modifier and Type	Optional Element and Description
String[]	capabilities Names of associated add-ons or capabilities
String[]	datasetTypes

Element Detail

datasetTypes

public abstract String[] datasetTypes

Default:

{}

capabilities

public abstract String[] capabilities

Names of associated add-ons or capabilities

Returns:

String array of capability names

Default:

{}