Parameters can be passed using the constructor or with parameters (configuration) method. Parameters will be serialized as part of the function object and passed to the task instance! Official website address batch

1 use constructor mode

DataSet<Integer> toFilter = env.fromElements(1, 2, 3);

toFilter.filter(new MyFilter(2));

private static class MyFilter implements FilterFunction<Integer> {

  private final int limit;

  public MyFilter(int limit) {
    this.limit = limit;
  }

  @Override
  public boolean filter(Integer value) throws Exception {
    return value > limit;
  }
}

2 with parameters (configuration) mode

This method will take a Configuration object as a parameter, which will be passed to the open method of Rich Function rich function ) The Configuration object is a Map that stores Key/Value key value pairs

DataSet<Integer> toFilter = env.fromElements(1, 2, 3);

Configuration config = new Configuration();
config.setInteger("limit", 2);

toFilter.filter(new RichFilterFunction<Integer>() {
    private int limit;

    @Override
    public void open(Configuration parameters) throws Exception {
      limit = parameters.getInteger("limit", 0);
    }

    @Override
    public boolean filter(Integer value) throws Exception {
      return value > limit;
    }
}).withParameters(config);

3 use the global execution config mode

Parameters can be obtained by all rich function s

Configuration conf = new Configuration();
conf.setString("mykey","myvalue");
final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();
env.getConfig().setGlobalJobParameters(conf);

public static final class Tokenizer extends RichFlatMapFunction<String, Tuple2<String, Integer>> {

    private String mykey;
    @Override
    public void open(Configuration parameters) throws Exception {
      super.open(parameters);
      ExecutionConfig.GlobalJobParameters globalParams = getRuntimeContext().getExecutionConfig().getGlobalJobParameters();
      Configuration globConf = (Configuration) globalParams;
      mykey = globConf.getString("mykey", null);
    }
    // ... more here ...