mapreduce-查找最高气温的Mapper类
浏览数：28 /
时间：2015年06月11日
package com;
import java.io.IOException;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Mapper;
public class MaxTemperatureMapper extends Mapper<LongWritable, Text, Text, IntWritable> {
private static final int MISSING = 9999;
@Override
public void map(LongWritable key, Text value, Context context) throws IOException, InterruptedException{
String line = value.toString();
String year = line.substring(15, 19);
int airTemperature;
if(line.charAt(87) == ‘+‘){
airTemperature = Integer.parseInt(line.substring(88, 92));
}else{
airTemperature = Integer.parseInt(line.substring(87, 92));
}
String quality = line.substring(92, 93);
if(airTemperature != MISSING && quality.matches("[01459]")){
context.write(new Text(year), new IntWritable(airTemperature));
}
}
}
import java.io.IOException;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Mapper;
public class MaxTemperatureMapper extends Mapper<LongWritable, Text, Text, IntWritable> {
private static final int MISSING = 9999;
@Override
public void map(LongWritable key, Text value, Context context) throws IOException, InterruptedException{
String line = value.toString();
String year = line.substring(15, 19);
int airTemperature;
if(line.charAt(87) == ‘+‘){
airTemperature = Integer.parseInt(line.substring(88, 92));
}else{
airTemperature = Integer.parseInt(line.substring(87, 92));
}
String quality = line.substring(92, 93);
if(airTemperature != MISSING && quality.matches("[01459]")){
context.write(new Text(year), new IntWritable(airTemperature));
}
}
}
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