import java.io.IOException;
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.Job;
import org.apache.hadoop.mapreduce.Mapper;
import org.apache.hadoop.mapreduce.Reducer;
import org.apache.hadoop.util.GenericOptionsParser;
import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
public class CallCount {
public static class BILLING_TERM_Mapper extends
Mapper<Object, Text, Text, IntWritable> {
private final static IntWritable one = new IntWritable(1);
private Text word = new Text();
public void map(Object key, Text value, Context context)
throws IOException, InterruptedException {
String line = value.toString();
String details[] = line.split(" ");
String BILLING = details[0];
String TERM = details[1];
String BILLING_TERM_String = BILLING + "-" + TERM;
word.set(BILLING_TERM_String);
if(!"null".equals(BILLING) && !"".equals(BILLING)){
context.write(word, one);
}
}
}
public static class BILLING_TERM_Reducer extends
Reducer<Text, IntWritable, Text, IntWritable> {
private IntWritable result = new IntWritable();
public void reduce(Text key, Iterable<IntWritable> values,
Context context) throws IOException, InterruptedException {
int sum = 0;
for (IntWritable val : values) {
sum += val.get();
}
result.set(sum);
context.write(key, result);
}
}
public static void main(String[] args) throws Exception{
Configuration conf = new Configuration();
String[] otherArgs = new GenericOptionsParser(conf, args).getRemainingArgs();
if (otherArgs.length != 2){
System.err.println("Usage: callcount ");
System.exit(2);
}
/** Create A Job, Give A name, Tracking It**/
Job job = new Job(conf, "Call Count");
job.setJarByClass(CallCount.class);
job.setMapperClass(BILLING_TERM_Mapper.class);
job.setCombinerClass(BILLING_TERM_Reducer.class);
job.setReducerClass(BILLING_TERM_Reducer.class);
job.setOutputKeyClass(Text.class);
job.setOutputValueClass(IntWritable.class);
FileInputFormat.addInputPath(job, new Path(otherArgs[0]));
FileOutputFormat.setOutputPath(job, new Path(otherArgs[1]));
System.exit(job.waitForCompletion(true) ? 0 : 1);
}
}
数据:

结果:
