Como definir um redutor para emitir <Text, IntWritable> e um mapeador para receber <Text, IntWritable>?
Estou desenvolvendo algum código emhadoop commapreduzir que usadois mapeadores e dois redutores. Foi-me dito para usarSequenceFileInputFormat eSequenceFileOutputFormat para que a saída do primeiro redutor e a entrada do segundo mapeador funcionem juntas. O problema é que estou registrando um erro e depoisgoogleing muito eu não sei porque.
O erro:
java.lang.Exception: java.io.IOException: Digite incompatibilidade na chave do mapa:esperado org.apache.hadoop.io.IntWritable, recebido org.apache.hadoop.io.Texto
Digite incompatibilidade na chave demapa: esperado org.apache.hadoop.io.IntWritable, recebido org.apache.hadoop.io.Texto
O código:
package casoTaxis;
import java.io.IOException;
import java.util.StringTokenizer;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.lib.input.SequenceFileInputFormat;
import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.mapreduce.Mapper;
import org.apache.hadoop.mapreduce.Reducer;
import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
import org.apache.hadoop.mapreduce.lib.output.SequenceFileOutputFormat;
public class Eje1{
public static class MapperJob1 extends Mapper<Object, Text, Text, IntWritable> {
//El metodo map recibe un conjunto clave-valor, lo procesa y lo vuelca en un contexto.adasdadada
public void map(Object key, Text value, Context context) throws IOException, InterruptedException {
Text hackLicense; IntWritable totalAmount; //salidas
StringTokenizer itr = new StringTokenizer(value.toString(), ",");
itr.nextToken();
hackLicense = new Text(itr.nextToken());
for(int i=2; i<itr.countTokens(); i++) itr.nextToken();
totalAmount = new IntWritable( Integer.parseInt(itr.nextToken()) );
context.write(hackLicense, totalAmount);
}
}
public static class ReducerJob1 extends Reducer<Text, IntWritable, Text, IntWritable> { //No encontre una clase InpuFormat que sea Text, IntWritable
public void reduce(Text key, Iterable<IntWritable> values, Context context) throws IOException, InterruptedException {
int sum = 0;
for (IntWritable val : values) {
sum += val.get();
}
context.write(key, new IntWritable(sum));
}
}
public static class MapperJob2 extends Mapper<Text, IntWritable, Text, IntWritable> {
//El metodo map recibe un conjunto clave-valor, lo procesa y lo vuelca en un contexto.adasdadada
public void map(Text key, IntWritable value, Context context) throws IOException, InterruptedException {
context.write(key, value);
}
}
public static class ReducerJob2 extends Reducer<Text, IntWritable, Text, Text> {
public void reduce(Text key, Iterable<IntWritable> values, Context context) throws IOException, InterruptedException {
int max = 0;
for (IntWritable val : values) {
int maxVal = val.get();
if( maxVal>max ) max = maxVal;
}
String licencia = "Conductor con licencia = " + key;
String recaudacion = "Recaudacion = " + max;
context.write(new Text(licencia), new Text(recaudacion));
}
}
public static void main(String[] args) throws Exception {
Configuration conf1 = new Configuration();
Configuration conf2 = new Configuration();
//conf2.set("mapreduce.input.keyvaluelinerecordreader.key.value.separator", " ");
Job job1 = Job.getInstance(conf1, "Eje1-Job1");
Job job2 = Job.getInstance(conf2, "Eje1-Job2");
job1.setJarByClass(Eje1.class);
job2.setJarByClass(Eje1.class);
job1.setMapperClass(MapperJob1.class);
job2.setMapperClass(MapperJob2.class);
job1.setReducerClass(ReducerJob1.class);
job2.setReducerClass(ReducerJob2.class);
job1.setMapOutputKeyClass(Text.class);
job1.setMapOutputValueClass(IntWritable.class);
job1.setOutputKeyClass(Text.class);
job1.setOutputValueClass(IntWritable.class);
job2.setMapOutputKeyClass(Text.class);
job2.setMapOutputKeyClass(IntWritable.class);
job2.setOutputKeyClass(Text.class);
job2.setOutputValueClass(Text.class);
job1.setOutputFormatClass(SequenceFileOutputFormat.class);
job2.setInputFormatClass(SequenceFileInputFormat.class);///asdasdads
FileInputFormat.addInputPath(job1, new Path(args[0]));
FileOutputFormat.setOutputPath(job1, pathIntermedio);
FileInputFormat.addInputPath(job2, pathIntermedio);
FileOutputFormat.setOutputPath(job2, new Path(args[1]));
job1.waitForCompletion(true);
System.exit(job2.waitForCompletion(true) ? 0 : 1);
}
private static final Path pathIntermedio = new Path("intermediate_output");
}
Por que estou recebendo esse erro? existe uma maneira melhor de conseguir isso?