Java tutorial
package com.thinkbiganalytics.spark.dataprofiler.functions; /*- * #%L * thinkbig-spark-job-profiler-spark-v2 * %% * Copyright (C) 2017 ThinkBig Analytics * %% * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. * #L% */ import org.apache.spark.api.java.function.PairFlatMapFunction; import org.apache.spark.sql.Row; import java.util.ArrayList; import java.util.Iterator; import java.util.List; import scala.Tuple2; /** * Get ((column index, column value), 1) for each column value in a row */ public class IndividualColumnValueCounts implements PairFlatMapFunction<Row, Tuple2<Integer, Object>, Integer> { @Override public Iterator<Tuple2<Tuple2<Integer, Object>, Integer>> call(Row row) throws Exception { List<Tuple2<Tuple2<Integer, Object>, Integer>> retValList = new ArrayList<>(); for (int i = 0; i < row.length(); i++) { Object value = row.get(i); Tuple2<Integer, Object> insideTuple = new Tuple2<>(i, value); Tuple2<Tuple2<Integer, Object>, Integer> fullTuple = new Tuple2<>(insideTuple, 1); retValList.add(fullTuple); } return retValList.iterator(); } }