myeclipse运行mapreduce报错：Cannot run program "cygpath": CreateProcess error=2,_myeclipse import.java.io.ioeception

直接上代码：Mapper

package com.winksi.dotstat;
import java.io.IOException;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.mapreduce.Mapper;
 
public class DotProducedMapper extends  Mapper<LongWritable, Text, Text, Text>{
	@Override
	public void map(LongWritable key, Text value, Context context) 
			throws IOException, InterruptedException{
		String line = value.toString();
		String fileds[] = line.split(",");
		String imsi = fileds[0];
		String adccompany = fileds[1];
		String phone = fileds[2];
		String cur_time = fileds[3];
		String call_length = fileds[4];
		String call_type = fileds[5];
		String show_length = fileds[6];
		String pkgname = fileds[7];
		String ip = fileds[8];
		String model = fileds[9];
		String ossdk = fileds[10];
		String av = fileds[11];
		String cityId = fileds[12];
		StringBuffer strKey = new StringBuffer();
		strKey.append(model).append(",").append(adccompany).append(",")
		.append(ossdk.toUpperCase()).append(",").append(av).append(",")
		.append(phone);
		context.write(new Text(strKey.toString()), new Text(imsi));
	}
}
 

Reducer:

package com.winksi.dotstat;
 
import java.io.IOException;
import java.util.Date;
import java.util.HashSet;
import java.util.Iterator;
import java.util.Set;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Reducer;
 
public class DotProducedReducer extends Reducer<Text, Text, Text, Text>{
	 public void reduce(Text key, Iterator<Text> values,
			 Context context)
		throws IOException, InterruptedException  {
		int count = 0;
		Set<String> set = new HashSet<String>();
		while (values.hasNext()) {
			set.add(values.next().toString());
            count++;
        }
		StringBuffer sb = new StringBuffer();
		sb.append(count).append(",").append(set.size());
		Date yesterdayDate = new Date(new Date().getTime() - 1*24*60*60*1000);
		String yesterday = DotStatPvUv.getCurrentDay(yesterdayDate);
		StringBuffer sbKey = new StringBuffer();
		sbKey.append(key.toString()).append(",").append(yesterday);
		context.write(new Text(sbKey.toString()), new Text(sb.toString()));
	}
}
 

Spring配置文件：

<?xml version="1.0" encoding="UTF-8"?>
<beans:beans xmlns="http://www.springframework.org/schema/hadoop"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:beans="http://www.springframework.org/schema/beans"
	xmlns:context="http://www.springframework.org/schema/context"
	xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
	http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd
	http://www.springframework.org/schema/hadoop http://www.springframework.org/schema/hadoop/spring-hadoop.xsd">
	<context:property-placeholder location="classpath:config.properties" />
	<configuration>
	  fs.default.name=${hd.fs}
	</configuration>
 
	<job id="dotProductJob"
	     input-path="${input.path}" 
	     output-path="${output.path}"
		 mapper="com.winksi.dotstat.DotProducedMapper"
		 reducer="com.winksi.dotstat.DotProducedReducer"/>
 
	<job-runner id="runner" run-at-startup="true"
			    job-ref="dotProductJob" />	
</beans:beans>

maven的jar包pom.xml

		<dependency>
			<groupId>org.springframework.data</groupId>
			<artifactId>spring-data-hadoop</artifactId>
			<version>1.0.2.RELEASE-cdh4</version>
		</dependency>
 
		<dependency>
			<groupId>org.apache.hadoop</groupId>
			<artifactId>hadoop-core</artifactId>
			<version>${hadoop.core.version}</version>
		</dependency>

java代码：

public class Test {
    public static void main(String[] args) {
         ApplicationContext ctx = new ClassPathXmlApplicationContext("hadoop-mr.xml");
    }
}

运行报错：

Exception in thread "main" java.io.IOException: Cannot run program "cygpath": CreateProcess error=2, ϵͳÕҲ»µ½ָ¶
 at java.lang.ProcessBuilder.start(ProcessBuilder.java:459)
 at org.apache.hadoop.util.Shell.runCommand(Shell.java:201)
 at org.apache.hadoop.util.Shell.run(Shell.java:183)
 at org.apache.hadoop.fs.FileUtil$CygPathCommand.<init>(FileUtil.java:413)
 at org.apache.hadoop.fs.FileUtil.makeShellPath(FileUtil.java:439)
 at org.apache.hadoop.fs.FileUtil.makeShellPath(FileUtil.java:466)
 at org.apache.hadoop.fs.RawLocalFileSystem.execCommand(RawLocalFileSystem.java:559)
 at org.apache.hadoop.fs.RawLocalFileSystem.setPermission(RawLocalFileSystem.java:551)
 at org.apache.hadoop.fs.RawLocalFileSystem.mkdirs(RawLocalFileSystem.java:355)
 at org.apache.hadoop.fs.FilterFileSystem.mkdirs(FilterFileSystem.java:212)

原因是尽管连接的hadoop平台是在linux上面，但是我们的eclipse调试环境是在windows，我们需要安装一个linux模拟器“cygwin”来支持程序的运行。

在windows开发服务器上安装好cygwin，然后在环境变量中添加cygwin的bin目录，比如“D:\Program\cygwin\bin”，问题得以解决。

注意是在系统环境变量的Path上加入“D:\Program\cygwin\bin”这样我们就行像在linux上运行命令一样在windows的dos窗口下执行ls,cd等命令。

刚开始我一直是在系统环境变量下的classpath上加的D:\Program\cygwin\bin”，尝试了半天都是失败，后来才发现，是加错了地方。加完之后再cmd窗口中试一下ls,cd等命令。成功后重启myeclipse运行代码，就没有问题了。

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之前纠结集成的Mapper和Reducer的问题，有两个文件可以继承，具体问题见：

http://wuyanzan60688.blog.163.com/blog/static/127776163201310164244955/