hadoop自己写的最高温度程序源码
package com.teset;
import java.io.IOException;
import java.util.StringTokenizer;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.conf.Configured;
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 org.apache.hadoop.util.Tool;
import org.apache.hadoop.util.ToolRunner;
public class Tempreature extends Configured implements Tool {
// 输入的是行偏移量,一行文本,输出的是 一个年份 最高温度
public static class TemMapper extends
Mapper<LongWritable, Text, Text, IntWritable> {
@Override
protected void map(LongWritable key, Text value,
Mapper<LongWritable, Text, Text, IntWritable>.Context context)
throws IOException, InterruptedException {
// map处理数据
String str = value.toString();
String year = null;
int Maxtemp = 0;
StringTokenizer tokenstr = new StringTokenizer(str);
int i=0;
while (tokenstr.hasMoreTokens()) {
String tempstr = tokenstr.nextToken();
i++;
if (i==1){
year =tempstr;
continue;
}else if (i==5&&Integer.parseInt(tempstr)!=-9999){
int tepMax = Integer.parseInt(tempstr);
Maxtemp =Math.max(tepMax, Maxtemp);
context.write(new Text(year), new IntWritable(Maxtemp));
break;
}
}
}
}
public static class TempReducer extends
Reducer<Text, IntWritable, Text, IntWritable> {
@Override
protected void reduce(Text key, Iterable<IntWritable> values,
Reducer<Text, IntWritable, Text, IntWritable>.Context context)
throws IOException, InterruptedException {
int Maxtem = Integer.MIN_VALUE;
for (IntWritable value:values){
Maxtem = Math.max(Maxtem, value.get());
}
context.write(key, new IntWritable(Maxtem));
}
}
public static void main(String[] args) throws Exception {
int res = ToolRunner.run(new Configuration(), new Tempreature(), args);
System.exit(res);
}
@Override
public int run(String[] arg0) throws Exception {
Configuration conf = getConf();
Job job = new Job(conf,"MaxTem");//任务名
job.setJarByClass(Tempreature.class);//指定class
//输入和输出流
FileInputFormat.addInputPath(job, new Path(arg0[0]));
FileOutputFormat.setOutputPath(job, new Path(arg0[1]));
job.setMapperClass(TemMapper.class);//map
job.setReducerClass(TempReducer.class);
job.setCombinerClass(TempReducer.class);
job.setOutputValueClass(IntWritable.class);
job.setOutputKeyClass(Text.class);
job.waitForCompletion(true);
return job.isSuccessful()?0:1;
}
}
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posted on 2015-05-10 16:10 MrCharles在cnblogs 阅读(155) 评论(0) 编辑 收藏 举报