Question

Idea 开发Mapreduce遇到的问题，代码不能自动实现方法！搞了很久没搞出来，哪位大牛知道这个？

包跟库都导入了，别的项目都能运行，就maven项目开发mapreduce的时候，代码不能给补齐，不能自动实现方法跟抛异常！下面是截图：

Answer 1

项目配置 File ---- Project Structure

1. SDK的配置

2. 加入Hadoop的jar包依赖

3.打包配置

4.开发map-reduce代码

<span style="font-size:18px;">import java.io.IOException;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.Path;
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 org.apache.hadoop.util.GenericOptionsParser;

public class Dedup {

//map将输入中的value复制到输出数据的key上，并直接输出
public static class Map extends Mapper<Object,Text,Text,Text>{
private static Text line=new Text();//每行数据

//实现map函数
public void map(Object key,Text value,Context context)
throws IOException,InterruptedException{

line=value;
context.write(line, new Text(""));
}

}

//reduce将输入中的key复制到输出数据的key上，并直接输出
public static class Reduce extends Reducer<Text,Text,Text,Text>{

//实现reduce函数
public void reduce(Text key,Iterable<Text> values,Context context)
throws IOException,InterruptedException{

context.write(key, new Text(""));
}

}

public static void main(String[] args) throws Exception{

Configuration conf = new Configuration();
String[] otherArgs = new GenericOptionsParser(conf, args).getRemainingArgs();

Job job = new Job(conf, "Data Deduplication");
job.setJarByClass(Dedup.class);

//设置Map、Combine和Reduce处理类
job.setMapperClass(Map.class);
job.setCombinerClass(Reduce.class);
job.setReducerClass(Reduce.class);

//设置输出类型
job.setOutputKeyClass(Text.class);
job.setOutputValueClass(Text.class);

//设置输入和输出目录
FileInputFormat.addInputPath(job, new Path(otherArgs[0]));
FileOutputForwww.cdxcxgs.com#tOutputPath(job, new Path(otherArgs[1]));
System.exit(job.waitForCompletion(true) ? 0 : 1);
}

}</span>

5.配置编译器