centos下使用Intellij IDEA 编写 word count

在CentOS 使用 ideaIC 开发工具 ideaIC

准备 idealC 安装包

ideaIC-2016.3.tar.gz  下载地址

上传到centos服务器上解压

tar -xzvf ideaIC-2016.2.3.tar.gz
进入bin目录打开idea.sh 进行安装



一切按照默认安装完成

创建项目 create new project



选择默认带的JDK 也可以 new sdk 选择本地安装的jdk也



下一步 template 不选 直接下一步 输入项目名称 WordCount 点击 Finish



写一个 main 方法测试一下 成功输出test...



开始编写 wordcount

导入hadoop包 (可以把所有jar放到一个文件夹引入)

File ->  Project Structure（快捷键 Ctrl + Alt + Shift + s），点击Project Structure界面左侧的“Modules”显示下图界面。



选择 Dependencies 加 右边 +



选择 1 JARs or directories...



编写代码如下：

package z.test;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.mapreduce.Mapper;
import org.apache.hadoop.mapreduce.Reducer;
import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
import java.io.IOException;

/**
* Created by z on .
*/
public class WordCount {
public static void main(String[] args) throws  Exception{
if(args.length == 0){
System.out.println("args is null exit....");
System.exit(0);
}

Configuration configuration = new Configuration();

Job job = new Job(configuration);
job.setJarByClass(WordCount.class);
FileInputFormat.setInputPaths(job,new Path(args[0]));
FileOutputFormat.setOutputPath(job,new Path(args[1]));

job.setMapperClass(TestMap.class);
job.setReducerClass(TestReduce.class);

job.setOutputKeyClass(Text.class);
job.setOutputValueClass(IntWritable.class);

job.waitForCompletion(true);
System.out.println("test....");

}

public static class TestMap extends Mapper{
@Override
protected void map(LongWritable key, Text value, Context  context) throws IOException, InterruptedException {

String[] words = value.toString().split(" ");
for (String word : words){
context.write(new Text(word),new IntWritable(1));
}

}
}

public static class TestReduce extends Reducer{
@Override
protected void reduce(Text key, Iterable values, org.apache.hadoop.mapreduce.Reducer.Context context) throws IOException, InterruptedException {

int count = 0;
for(IntWritable i : values){
count += i.get();
}
context.write(key,new IntWritable(count));
}
}

}

打包

File->project stucture

Artifacts->"+",选jar，选择from modules with dependencies，然后会有配置窗口出现，配置完成后，勾选Build on make >ok保存



启动hadop sbin/start-all.sh

执行 jar 包

hadoop jar WordCount.jar z.test.WordCount /in/words /out/wordcount

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