Hadoop Map/Reduce 示例程序WordCount

时间:2022-06-22 19:26:42

#进入hadoop安装目录

cd /usr/local/hadoop

#创建示例文件:input

#在里面输入以下内容:

#Hello world, Bye world!

vim input

#在hdfs上创建文件路径

bin/hadoop fs -mkdir  /user/root/test/wordcount

#将输入文件拷贝到hdfs

bin/hadoop fs -put input /user/root/test/wordcount

#执行程序

bin/hadoop jar hadoop-examples-1.0.3.jar wordcount /user/root/test/wordcount /user/root/test/wordcount/output

#程序在执行完毕后查看执行结果

bin/hadoop fs -cat /user/root/test/wordcount/output/*

#程序将会输出下面的结果(请忽略最后一句^_^):

Bye 1
Hello 1
world! 1
world, 1
cat: File does not exist: /user/root/test/wordcount/output/_logs

#至此,map/reduce执行完毕。