{{{
#!html
<div style="text-align: center;"><big
 style="font-weight: bold;"><big><big>實做四: Hadoop 程式編譯</big></big></big></div>
}}}
[[PageOutline]]

 = 練習 0 : hello : 印出我們的 key value 為何 = 



 * 下載 [http://trac.nchc.org.tw/cloud/raw-attachment/wiki/Hadoop_Lab4/nchc-example.jar nchc-example.jar]
 {{{
$ wget http://trac.nchc.org.tw/cloud/raw-attachment/wiki/Hadoop_Lab4/nchc-example.jar
 }}}

 * 執行客製化的hadoop 程式 

{{{
$ bin/hadoop jar nchc-example.jar
}}}
 * 輸出結果
{{{
******************************************
歡迎使用 NCHC.Hadoop 的運算功能
指令：
  Hadoop jar nchc-example-*.jar <功能>
功能：
  wordcount: 計算輸入資料夾內分別在每個檔案的字數統計
  mwc:       統合計算所有輸入檔的字數統計
  grep:      算出包指定字串的個數
  nchcgrep:  整合來源檔內的每個字與其所有出現的所在列
  hello:     印出內容並統計累進字數
******************************************

}}}
 * 使用hello
{{{
$ bin/hadoop jar nchc-example.jar hello
}}}
 * 使用提示：
{{{
hello <inDir> <outDir> <m> <r>
}}}

 * 範例：

{{{
$ bin/hadoop jar nchc-example.jar hello lab3_input lab4_out6 1 1
}}}

[wiki:Hadoop_Lab4_hello_018 hello 程式碼]

 = 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
}}}

 * 下載 [raw-attachment:wiki:Hadoop_Lab4:WordCount.java WordCount.java] 並存到/opt/hadoop;
{{{
$ wget trac.nchc.org.tw/cloud/wiki/Hadoop_Lab4/WordCount.java
}}}

 * 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 
{{{
#!text
Cloud	2
Course,	1
Course.	1
I	2
NCHC	1
and	1
course.	1
enjoy	1
like	2
nchc	1
this	1
we	1
}}}
-----

 = 練習 2 : Word Count 進階版 =

{{{
$ echo "\." >pattern.txt && echo "\," >>pattern.txt
$ bin/hadoop fs -put pattern.txt ./
$ mkdir MyJava2
}}}


 * 下載 [raw-attachment:wiki:Hadoop_Lab4:WordCount2.java WordCount2.java] 並存到/opt/hadoop;
{{{
$ wget trac.nchc.org.tw/cloud/wiki/Hadoop_Lab4/WordCount2.java
}}}

{{{
$ javac -classpath hadoop-*-core.jar -d MyJava2 WordCount2.java
$ jar -cvf wordcount2.jar -C MyJava2 .
$ bin/hadoop jar wordcount2.jar WordCount2 lab4_input lab4_out2 -skip pattern.txt
$ bin/hadoop fs -cat lab4_out2/part-00000
}}}

 * lab4_out2 執行結果
{{{
#!text
Cloud	2
Course	2
I	2
NCHC	1
and	1
course	1
enjoy	1
like	2
nchc	1
this	1
we	1
}}}

{{{
$ bin/hadoop jar wordcount2.jar WordCount2 -Dwordcount.case.sensitive=false lab4_input lab4_out3 -skip pattern.txt
$ bin/hadoop fs -cat lab4_out3/part-00000
}}}

 * lab4_out3 執行結果
{{{
#!text
and	1
cloud	2
course	3
enjoy	1
i	2
like	2
nchc	2
this	1
we	1
}}}