package max;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.LongWritable;
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.mapreduce.lib.input.FileInputFormat;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
import java.io.IOException;
public class MaxValueMain {
public static void main(String[] args) throws IOException, ClassNotFoundException, InterruptedException {
Configuration conf=new Configuration();
conf.set("fs.defaultFs","hdfs://192.168.37.45:8020");
Job job =Job.getInstance(conf,"maxvalue");
job.setJarByClass(MaxValueMain.class);
job.setMapperClass(MaxValueMapper.class);
job.setReducerClass(MaxValueReducer.class);
FileInputFormat.setInputPaths(job,new Path("/maxvalue"));
FileOutputFormat.setOutputPath(job,new Path("/maxoutput"));
job.setMapOutputKeyClass(Text.class);
job.setMapOutputValueClass(Text.class);
job.setOutputKeyClass(Text.class);
job.setOutputValueClass(IntWritable.class);
job.waitForCompletion(true);
}
public static class MaxValueMapper extends Mapper<LongWritable, Text,Text,Text> {
@Override
protected void map(LongWritable key, Text value, Context context) throws IOException, InterruptedException {
String[] values=value.toString().split(" ");
context.write(new Text(values[0]), new Text(values[1] + "," + values[2]));
}
}
public static class MaxValueReducer extends Reducer<Text,Text,Text, IntWritable> {
@Override
protected void reduce(Text key, Iterable<Text> values, Context context) throws IOException, InterruptedException {
int max=-2323113;
String month ="";
for (Text val:values){
String[] result=val.toString().split(",");
String mh=result[0];
int vs= Integer.parseInt(result[1]);
max=vs>max?vs:max;//if (vs>max){max=vs;}else{max=max;}
if (vs>max){
month=mh;
}
}
context.write(new Text(key.toString()+month),new IntWritable(max));
}
}
}