嗨,我有麻烦了,我还没有得到类似线程的帮助。我正在做一个hadoop工作的例子,我现在正试图从ide运行它。这是我的源代码
package org.myorg;
import java.io.IOException;
import java.util.*;
import org.apache.hadoop.io.*;
import org.apache.hadoop.conf.*;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.mapred.*;
import org.apache.hadoop.util.*;
public class WordCount
{
public static class Map extends MapReduceBase implements Mapper<LongWritable, Text, Text, IntWritable> {
private final static IntWritable one = new IntWritable(1);
private Text word = new Text();
public void map(LongWritable key, Text value, OutputCollector<Text, IntWritable> output, Reporter reporter) throws IOException
{
String line = value.toString().toLowerCase().replaceAll("\\p{Punct}|\\d","");
StringTokenizer tokenizer = new StringTokenizer(line);
while (tokenizer.hasMoreTokens())
{
word.set(tokenizer.nextToken());
output.collect(word, one);
}// end while
}// end public void map
}// end public static class Map
public static class Reduce extends MapReduceBase implements Reducer<Text, IntWritable, Text, IntWritable>
{
public void reduce(Text key, Iterator<IntWritable> values, OutputCollector<Text, IntWritable> output, Reporter reporter) throws IOException
{
int sum = 0;
while (values.hasNext())
{
sum+= values.next().get();
}// end while
output.collect(key, new IntWritable(sum));
}// end public void reduce
}// end public static class Reduce
public static void main(String[] args) throws Exception
{
JobConf conf = new JobConf(org.myorg.WordCount.class);
conf.setJobName("wordcount");
conf.setOutputKeyClass(Text.class);
conf.setOutputValueClass(IntWritable.class);
conf.setMapperClass(Map.class);
conf.setCombinerClass(Reduce.class);
conf.setReducerClass(Reduce.class);
conf.setInputFormat(TextInputFormat.class);
conf.setOutputFormat(TextOutputFormat.class);
FileInputFormat.setInputPaths(conf, new Path(args[0]));
FileOutputFormat.setOutputPath(conf, new Path(args[1]));
JobClient.runJob(conf);
}// end main
}//end public class WordCount
这是我得到的一个例外。有人有什么想法吗?
Exception in thread "main" java.lang.NoClassDefFoundError: org/apache/log4j/Level
at org.apache.hadoop.mapred.JobConf.<clinit>(JobConf.java:362)
at org.myorg.WordCount.main(WordCount.java:56)
Caused by: java.lang.ClassNotFoundException: org.apache.log4j.Level
at java.net.URLClassLoader$1.run(URLClassLoader.java:366)
at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
at java.lang.ClassLoader.loadClass(ClassLoader.java:425)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
at java.lang.ClassLoader.loadClass(ClassLoader.java:358)
1条答案
按热度按时间wooyq4lh1#
显然,它缺少log4j的jar文件。您应该将jar添加到类路径中。