myeclipse运行mapreduce报错：Cannot run program "cygpath": CreateProcess error=2,

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>{@Overridepublic 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.xsdhttp://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsdhttp://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。

------------------------------------------------------------------------------

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/