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From Stanley Shi <s...@gopivotal.com>
Subject Re: Re: Hadoop NoClassDefFoundError
Date Wed, 16 Apr 2014 02:25:27 GMT
can do you an "unzip -l myjob.jar" to see if your jar file has the correct
hierarchy?

Regards,
*Stanley Shi,*



On Tue, Apr 15, 2014 at 6:53 PM, laozhao0@sina.cn <laozhao0@sina.cn> wrote:

> Thank you for your advice . When i user your command , i get the below
> error info .
> $ hadoop jar myjob.jar myjob.MyJob input output
> Exception in thread "main" java.lang.ClassNotFoundException: myjob.MyJob
> 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:423)
> at java.lang.ClassLoader.loadClass(ClassLoader.java:356)
> at java.lang.Class.forName0(Native Method)
> at java.lang.Class.forName(Class.java:264)
> at org.apache.hadoop.util.RunJar.main(RunJar.java:149)
>
> ------------------------------
>
>
> *From:* Azuryy Yu <azuryyyu@gmail.com>
> *Date:* 2014-04-15 16:14
> *To:* user@hadoop.apache.org
> *Subject:* Re: Hadoop NoClassDefFoundError
> Please use: hadoop jar myjob.jar myjob.MyJob input output
>
>
> On Tue, Apr 15, 2014 at 3:06 PM, laozhao0@sina.cn <laozhao0@sina.cn>wrote:
>
>> Hello EveryOne:
>>     I am new to hadoop,and i am reading Hadoop in action.
>> When i tried to run a demo from this book,I got a problem and could not
>> find answer from the net. Can you help me on this ?
>>
>> below is the error info :
>>
>>   $ hadoop jar myjob.jar MyJob input output
>> Exception in thread "main" java.lang.NoClassDefFoundError: MyJob (wrong
>> name: myjob/MyJob)
>> at java.lang.ClassLoader.defineClass1(Native Method)
>> at java.lang.ClassLoader.defineClass(ClassLoader.java:791)
>> at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
>> at java.net.URLClassLoader.defineClass(URLClassLoader.java:449)
>> at java.net.URLClassLoader.access$100(URLClassLoader.java:71)
>> at java.net.URLClassLoader$1.run(URLClassLoader.java:361)
>> 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:423)
>> at java.lang.ClassLoader.loadClass(ClassLoader.java:356)
>> at java.lang.Class.forName0(Native Method)
>> at java.lang.Class.forName(Class.java:264)
>> at org.apache.hadoop.util.RunJar.main(RunJar.java:149)
>>
>> and this is the command that i compile the .java , I compiled in Win7 and
>> ran on ubuntu .
>>
>>
>> below is MyJob.java
>>
>> package myjob;
>>
>> import java.io.IOException;
>> import java.util.Iterator;
>>
>> import org.apache.hadoop.conf.Configuration;
>> import org.apache.hadoop.conf.Configured;
>> import org.apache.hadoop.fs.Path;
>> import org.apache.hadoop.io.Text;
>> import org.apache.hadoop.mapred.FileInputFormat;
>> import org.apache.hadoop.mapred.FileOutputFormat;
>> import org.apache.hadoop.mapred.JobClient;
>> import org.apache.hadoop.mapred.JobConf;
>> import org.apache.hadoop.mapred.KeyValueTextInputFormat;
>> import org.apache.hadoop.mapred.MapReduceBase;
>> import org.apache.hadoop.mapred.Mapper;
>> import org.apache.hadoop.mapred.OutputCollector;
>> import org.apache.hadoop.mapred.Reducer;
>> import org.apache.hadoop.mapred.Reporter;
>> import org.apache.hadoop.mapred.TextOutputFormat;
>> import org.apache.hadoop.util.Tool;
>> import org.apache.hadoop.util.ToolRunner;
>>
>> public class MyJob extends Configured implements Tool{
>>
>> @Override
>> public int run(String[] args) throws Exception {
>> Configuration conf = getConf();
>> JobConf job = new JobConf(conf,MyJob.class);
>> Path in = new Path(args[0]);
>> Path out = new Path(args[1]);
>> FileInputFormat.setInputPaths(job, in);
>> FileOutputFormat.setOutputPath(job, out);
>> job.setJobName("MyJob");
>> job.setJarByClass(MyJob.class);
>> job.setMapperClass(MapClass.class);
>> job.setReducerClass(Reduce.class);
>>
>> job.setInputFormat(KeyValueTextInputFormat.class);
>> job.setOutputFormat(TextOutputFormat.class);
>> job.setOutputKeyClass(Text.class);
>> job.setOutputValueClass(Text.class);
>> job.set("key.value.separator.in.input.line",",");
>> JobClient.runJob(job);
>> return 0;
>> }
>>
>> public static class MapClass extends MapReduceBase implements
>> Mapper<Text,Text,Text,Text>{
>>
>> @Override
>> public void map(Text key, Text value, OutputCollector<Text, Text> output,
>> Reporter reporter) throws IOException {
>> output.collect(value, key);
>> }
>> }
>>
>> public static class Reduce extends MapReduceBase implements
>> Reducer<Text,Text,Text,Text>{
>>
>> @Override
>> public void reduce(Text key, Iterator<Text> values,
>> OutputCollector<Text, Text> output, Reporter reporter)
>> throws IOException {
>> String csv = "";
>> while(values.hasNext()){
>> if(csv.length() > 0)
>> csv += ",";
>> csv += values.next().toString();
>> }
>> }
>> }
>>
>> public static void main(String[] args) throws Exception {
>> int res = ToolRunner.run(new Configuration(), new MyJob(), args);
>> System.exit(res);
>> }
>> }
>> ------------------------------
>> Thank you for your kindly help !
>>
>
>

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