第七步：新建一个WordCount.java，这里使用系统自带的TokenCountMapper和LongSumReducer，代码如下：
package com.baison.action;
import org.apache.Hadoop.fs.Path;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.mapred.FileInputFormat;
import org.apache.hadoop.mapred.FileOutputFormat;
import org.apache.hadoop.mapred.JobClient;
import org.apache.hadoop.mapred.JobConf;
import org.apache.hadoop.mapred.lib.TokenCountMapper;
import org.apache.hadoop.mapred.lib.LongSumReducer;
public class WordCount {
public static void main(String[] args) {
JobClient client = new JobClient();
JobConf conf = new JobConf(WordCount.class);
String[] arg = { "hdfs://localhost:9100/user/tanglg1987/input",
"hdfs://localhost:9100/user/tanglg1987/output" };
FileInputFormat.addInputPath(conf, new Path(arg[0]));
FileOutputFormat.setOutputPath(conf, new Path(arg[1]));
conf.setOutputKeyClass(Text.class);
conf.setOutputValueClass(LongWritable.class);
conf.setMapperClass(TokenCountMapper.class);
conf.setCombinerClass(LongSumReducer.class);
conf.setReducerClass(LongSumReducer.class);
client.setConf(conf);
try {
JobClient.runJob(conf);
} catch (Exception e) {
e.printStackTrace();
}
}
}
