package inputformat;
import java.net.URI;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
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.lib.input.FileInputFormat;
import org.apache.hadoop.mapreduce.lib.input.KeyValueLineRecordReader;
import org.apache.hadoop.mapreduce.lib.input.KeyValueTextInputFormat;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
/**
* hello you hello you
* hello me
*
*/
public class MyKeyValueTextInputFormatApp {
private static final String INPUT_PATH = "hdfs://chaoren1:9000/hello";
private static final String OUT_PATH = "hdfs://chaoren1:9000/out";
public static void main(String[] args) throws Exception{
Configuration conf = new Configuration();
//使用特定的分割符分开
conf.set(KeyValueLineRecordReader.KEY_VALUE_SEPERATOR, "\t");
final FileSystem filesystem = FileSystem.get(new URI(OUT_PATH), conf);
filesystem.delete(new Path(OUT_PATH), true);
final Job job = new Job(conf , MyKeyValueTextInputFormatApp.class.getSimpleName());
job.setJarByClass(MyKeyValueTextInputFormatApp.class);
FileInputFormat.setInputPaths(job, INPUT_PATH);
job.setInputFormatClass(KeyValueTextInputFormat.class);
job.setMapperClass(MyMapper.class);
job.setMapOutputKeyClass(Text.class);
job.setMapOutputValueClass(LongWritable.class);
job.setNumReduceTasks(0);
job.setOutputKeyClass(Text.class);
job.setOutputValueClass(LongWritable.class);
FileOutputFormat.setOutputPath(job, new Path(OUT_PATH));
job.waitForCompletion(true);
}
public static class MyMapper extends Mapper<Text, Text, Text, LongWritable>{
protected void map(Text key, Text value, org.apache.hadoop.mapreduce.Mapper<Text,Text,Text,LongWritable>.Context context) throws java.io.IOException ,InterruptedException {
context.write(key, new LongWritable(1));
context.write(value, new LongWritable(1));
};
}
}