之前是用Map/Reduce项目来运行hadoop的,这是直接Run on hadoop的,参见:http://blog.youkuaiyun.com/cafebar123/article/details/73611341
下面用java Application 来运行wordcount 程序。
(1)前提条件:
1.eclipse中集成maven插件;
2.eclipse中集成hadoop插件;
3.eclipse中可以运行Map/Reduce项目,并可以得到有效结果。
(2)Maven构建hadoop环境
打开window 命令控制台,输入:
e:
cd E:\eclipse demo\myHadoop
mvn archetype:generate -DarchetypeGroupId=org.apache.maven.archetypes -DgroupId=org.myhadoop.wordcount -DartifactId=myHadoop -DpackageName=org.myhadoop.wordcount -Dversion=1.0-SNAPSHOT -DinteractiveMode=false
接着看下载界面,如图:
这样会构建一个java项目。
(3)安装需要的jar包。
cd E:\eclipse demo\myHadoop\myHadoop
mvn clean install
(4)将maven构建的java项目导入eclipse中。
(5)在pom.xml 中增加依赖包:
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>org.myhadoop.wordcount</groupId>
<artifactId>myHadoop</artifactId>
<packaging>jar</packaging>
<version>1.0-SNAPSHOT</version>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<hadoop.version>2.7.3</hadoop.version>
</properties>
<name>myHadoop</name>
<url>http://maven.apache.org</url>
<dependencies>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.4</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.apache.hadoop</groupId>
<artifactId>hadoop-client</a