package crunch;
import static com.cloudera.crunch.type.writable.Writables.strings;
import static com.cloudera.crunch.type.writable.Writables.tableOf;
import java.io.IOException;
import java.io.Serializable;
import java.util.Iterator;
import org.junit.Test;
import com.cloudera.crunch.DoFn;
import com.cloudera.crunch.Emitter;
import com.cloudera.crunch.PCollection;
import com.cloudera.crunch.PTable;
import com.cloudera.crunch.Pair;
import com.cloudera.crunch.Pipeline;
import com.cloudera.crunch.impl.mr.MRPipeline;
import com.cloudera.crunch.lib.Join;
import com.google.common.base.Splitter;
public class JoinCrunchTest implements Serializable {
@Test
public void test() throws IOException {
Pipeline pipeline = new MRPipeline(JoinCrunchTest.class);
PCollection<String> a = pipeline.readTextFile("join/A");
PCollection<String> b = pipeline.readTextFile("join/B");
PTable<String, String> aTable = a.parallelDo(new DoFn<String, Pair<String, String>>() {
@Override
public void process(String input, Emitter<Pair<String, String>> emitter) {
Iterator<String> split = Splitter.on('\t').split(input).iterator();
emitter.emit(Pair.of(split.next(), split.next()));
}
}, tableOf(strings(),strings()));
PTable<String, String> bTable = b.parallelDo(new DoFn<String, Pair<String, String>>() {
@Override
public void process(String input, Emitter<Pair<String, String>> emitter) {
Iterator<String> split = Splitter.on('\t').split(input).iterator();
String l = split.next();
String r = split.next();
emitter.emit(Pair.of(r, l));
}
}, tableOf(strings(),strings()));
PTable<String, Pair<String, String>> join = Join.join(aTable, bTable);
pipeline.writeTextFile(join, "output-joined");
pipeline.run();
}
}