package iie.udps.example.operator.spark;

import scala.Tuple2;

import org.apache.hadoop.conf.Configuration;

import org.apache.hadoop.io.LongWritable;

import org.apache.hadoop.io.Text;

import org.apache.hadoop.mapreduce.lib.input.TextInputFormat;

import org.apache.spark.SparkConf;

import org.apache.spark.api.java.JavaPairRDD;

import org.apache.spark.api.java.JavaRDD;

import org.apache.spark.api.java.JavaSparkContext;

import org.apache.spark.api.java.function.FlatMapFunction;

import org.apache.spark.api.java.function.Function;

import org.apache.spark.api.java.function.Function2;

import org.apache.spark.api.java.function.PairFunction;

import java.io.UnsupportedEncodingException;

import java.nio.charset.Charset;

import java.util.Arrays;

import java.util.regex.Pattern;

/**

 * 利用Spark框架读取HDFS文件，文件格式为GB2312，转换为UTF-8，实现WordCount示例

 *

 * 执行命令：spark-submit --class iie.hadoop.hcatalog.TextFileSparkTest --master

 * yarn-cluster /tmp/sparkTest.jar hdfs://192.168.8.101/test/words

 * hdfs://192.168.8.101/test/spark/out

 *

 *

 */

public final class SparkChangeTextCharsetTest {

	private static final Pattern SPACE = Pattern.compile(",");

	@SuppressWarnings("serial")

	public static void main(String[] args) throws Exception {

		if (args.length < 2) {

			System.err.println("Usage: JavaWordCount <file>");

			System.exit(1);

		}

		String inputSparkFile = args[0];

		String outputSparkFile = args[1];

		SparkConf sparkConf = new SparkConf().setAppName("SparkWordCount");

		JavaSparkContext ctx = new JavaSparkContext(sparkConf);

		Configuration conf = new Configuration();

		JavaPairRDD<LongWritable, Text> contents = ctx.newAPIHadoopFile(

				inputSparkFile, TextInputFormat.class, LongWritable.class,

				Text.class, conf);

		JavaRDD<String> lines = contents

				.map(new Function<Tuple2<LongWritable, Text>, String>() {

					public String call(Tuple2<LongWritable, Text> x) {

						String lines = null;

						try {

							lines = new String(x._2().getBytes(), 0, x._2()

									.getLength(), "GB2312");

						} catch (UnsupportedEncodingException e) {

							e.printStackTrace();

						}

						return lines;

					}

				});

		// JavaRDD<String> changeLines = lines

		// .filter(new Function<String, Boolean>() {

		// public Boolean call(String s) {

		// return s.contains("234");

		// }

		// });

		 JavaRDD<String> words = lines

		 .flatMap(new FlatMapFunction<String, String>() {

		 @Override

		 public Iterable<String> call(String s) {

		 return Arrays.asList(SPACE.split(s));

		 }

		 });

		 JavaPairRDD<String, Integer> ones = words

		 .mapToPair(new PairFunction<String, String, Integer>() {

		 @Override

		 public Tuple2<String, Integer> call(String s) {

		 return new Tuple2<String, Integer>(s, 1);

		 }

		 });

		 JavaPairRDD<String, Integer> counts = ones

		 .reduceByKey(new Function2<Integer, Integer, Integer>() {

		 @Override

		 public Integer call(Integer i1, Integer i2) {

		 return i1 + i2;

		 }

		 });

		 counts.map(new Function<Tuple2<String, Integer>, String>() {

		 @Override

		 public String call(Tuple2<String, Integer> arg0) throws Exception {

		 return arg0._1.toUpperCase() + ": " + arg0._2;

		 }

		 }).saveAsTextFile(outputSparkFile);

		ctx.stop();

	}

}