實做四: Hadoop 程式編譯

練習 1 : Word Count 初級版

• 上傳內容到hdfs內

$ cd /opt/hadoop
$ mkdir lab4_input
$ echo "I like NCHC Cloud Course." > lab4_input/input1
$ echo "I like nchc Cloud Course, and we enjoy this course." > lab4_input/input2
$ bin/hadoop fs -put lab4_input lab4_input
$ bin/hadoop fs -ls lab4_input

• 編輯 wordcount.java 並存到/opt/hadoop;

• 運作程式

$ mkdir MyJava
$ javac -classpath hadoop-*-core.jar -d MyJava WordCount.java
$ jar -cvf wordcount.jar -C MyJava .
$ bin/hadoop jar wordcount.jar WordCount lab4_input/ lab4_out1/
$ bin/hadoop fs -cat lab4_out1/part-00000

• lab4_out1 執行結果

  Cloud 2
  Course, 1
  Course. 1
  I 2
  NCHC  1
  and 1
  course. 1
  enjoy 1
  like  2
  nchc  1
  this  1
  we  1
  

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