import org.apache.hadoop.io.Text; import org.apache.hadoop.mapreduce.Reducer; import java.io.IOException; public class ProvinceMaxDailyPowerReducer extends Reducer { @Override protected void reduce(Text key, Iterable values, Context context) throws IOException, InterruptedException { String maxRecord = null; double maxValue = Double.MIN_VALUE; for (Text value : values) { String[] parts = value.toString().split(":"); double powerUsage = Double.parseDouble(parts[2]); if (powerUsage > maxValue) { maxValue = powerUsage; maxRecord = value.toString(); } } if (maxRecord != null) { context.write(key, new Text(maxRecord)); } } }