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a scala Wordcount
import java.io.IOException
import java.util._
import org.apache.hadoop.fs.Path
import org.apache.hadoop.conf._
import org.apache.hadoop.io._
import org.apache.hadoop.mapreduce._
import org.apache.hadoop.util._
import org.apache.hadoop.mapreduce.lib.input.FileInputFormat
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat
//import BIDMat.MatFunctions._
//import BIDMat.IMat
import scala.reflect.Manifest
import java.io.PrintWriter
import org.apache.commons.cli.Options
object WordCount2 extends Configured with Tool {
class Map extends Mapper[LongWritable, Text, Text, IntWritable] {
var one: IntWritable = new IntWritable(1);
//var word: Text = new Text();
override def map(key: LongWritable, value: Text, context: Mapper[LongWritable, Text, Text, IntWritable]#Context) {
// var a : IMat = 1\2\3
var line: String = value.toString();
for(word <- line.split(" ")){
context.write(new Text(word), one)
}
/*
var tokenizer: StringTokenizer = new StringTokenizer(line);
while (tokenizer.hasMoreTokens()) {
word.set(tokenizer.nextToken());
context.write(word, one);
}
*/
}
}
class Reduce extends Reducer[Text, IntWritable, Text, IntWritable] {
override def reduce(key: Text, values: java.lang.Iterable[IntWritable], context:Reducer[Text, IntWritable, Text, IntWritable]#Context) {
val ivalues = values.iterator
val svals = new scala.collection.Iterator[Int]{
def hasNext = ivalues.hasNext
def next = ivalues.next.get
}
val sum = (svals : scala.collection.Iterator[Int]).reduceLeft (
(a: Int, b: Int) => a + b
)
context.write(key, new IntWritable(sum))
/*
var sum: Int = 0;
while (values.hasNext()) {
sum += values.next().get();
}
context.write(key,new IntWritable(sum))
*/
}
}
def run(args: Array[String]) =
{
var conf = super.getConf()
// Configuration.dumpConfiguration(conf,new PrintWriter(System.out)) // for verfying your conf file
// println("Libjars: " + conf.get("tmpjars")); //for making sure your jars have been include
var job : Job = new Job(conf,"WordCount2")
job
job setJarByClass(this.getClass())
job setOutputKeyClass classOf[Text]
job setOutputValueClass classOf[IntWritable]
job setMapperClass classOf[Map]
job setCombinerClass classOf[Reduce]
job setReducerClass classOf[Reduce]
FileInputFormat.addInputPath(job, new Path(args(1)))
FileOutputFormat.setOutputPath(job, new Path(args(2)))
job waitForCompletion(true) match {
case true => 0
case false => 1
}
}
def main(args: Array[String]) {
var c : Configuration = new Configuration()
var res : Int = ToolRunner.run(c,this, args)
System.exit(res);
}
}
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