hadoop安装计

大体上按这个做就好了
http://blog.csdn.net/hitwengqi/article/details/8008203

需要修改hadoop-env.sh
export JAVA_HOME=/usr/lib/jvm/java-6-openjdk-amd64
export PATH=$PATH:/usr/local/hadoop/bin

rm -r ~/playground/classes/* #删除编译后的文件
rm ~/playground/wordcount.jar #删除jar包
rm -r ~/output #删除wordcount产生的文档

#编译WordCount.java
javac -classpath /usr/local/hadoop/share/hadoop/mapreduce/hadoop-mapreduce-client-core-2.2.0.jar:/usr/local/hadoop/share/hadoop/common/hadoop-common-2.2.0.jar:/usr/local/hadoop/share/hadoop/common/lib/commons-cli-1.2.jar -d ~/playground/classes ~/playground/src/WordCount.java

#jar打包
# -C切换目录
jar -cvf ~/playground/wordcount.jar -C ~/playground/classes/ .

#hadoop执行命令
hadoop jar ~/playground/wordcount.jar home.goodspeed.playground.classes.org.apache.hadoop.WordCount ~/input ~/output