Package org.apache.flink.hadoopcompatibility.mapred

Class HadoopMapFunction<KEYIN,​VALUEIN,​KEYOUT,​VALUEOUT>

    • Constructor Detail

      • HadoopMapFunction

        public HadoopMapFunction​(org.apache.hadoop.mapred.Mapper<KEYIN,​VALUEIN,​KEYOUT,​VALUEOUT> hadoopMapper)
        Maps a Hadoop Mapper (mapred API) to a Flink FlatMapFunction.
        Parameters:
        hadoopMapper - The Hadoop Mapper to wrap.

      • HadoopMapFunction

        public HadoopMapFunction​(org.apache.hadoop.mapred.Mapper<KEYIN,​VALUEIN,​KEYOUT,​VALUEOUT> hadoopMapper,
                         org.apache.hadoop.mapred.JobConf conf)
        Maps a Hadoop Mapper (mapred API) to a Flink FlatMapFunction. The Hadoop Mapper is configured with the provided JobConf.
        Parameters:
        hadoopMapper - The Hadoop Mapper to wrap.
        conf - The JobConf that is used to configure the Hadoop Mapper.

    • Method Detail

      • open

        @PublicEvolving
public void open​(OpenContext openContext)
          throws Exception
        Description copied from interface: RichFunction
        Initialization method for the function. It is called before the actual working methods (like map or join) and thus suitable for one time setup work. For functions that are part of an iteration, this method will be invoked at the beginning of each iteration superstep.

        The openContext object passed to the function can be used for configuration and initialization. The openContext contains some necessary information that were configured on the function in the program composition. 

        
 public class MyFilter extends RichFilterFunction<String> {

     private String searchString;

     public void open(OpenContext openContext) {
         // initialize the value of searchString
     }

     public boolean filter(String value) {
         return value.equals(searchString);
     }
 }
        Specified by:
        open in interface RichFunction
        Overrides:
        open in class AbstractRichFunction
        Parameters:
        openContext - The context containing information about the context in which the function is opened.
        Throws:
        Exception - Implementations may forward exceptions, which are caught by the runtime. When the runtime catches an exception, it aborts the task and lets the fail-over logic decide whether to retry the task execution.