我正在尝试将 csv 文件转换为序列文件，以便我可以在数据中训练和运行分类器。我有一个我编译的作业 java 文件，然后 jar 到 mahout 作业 jar 中。当我尝试hadoop jar在 mahout jar 中工作时，我得到一个java.lang.ClassNotFoundException: org.apache.mahout.math.VectorWritable. 我不知道为什么会这样，因为如果我查看 mahout jar，那个类确实存在。
这是我正在做的步骤
#get new copy of mahout jar
rm iris.jar
cp /home/stephen/home/libs/mahout-distribution-0.7/core/target/mahout-core-0.7-job.jar iris.jar
javac -cp :/home/stephen/home/libs/hadoop-1.0.4/hadoop-core-1.0.4.jar:/home/stephen/home/libs/mahout-distribution-0.7/core/target/mahout-core-0.7-job.jar -d bin/ src/edu/iris/seq/CsvToSequenceFile.java
jar ufv iris.jar -C bin .
hadoop jar iris.jar edu.iris.seq.CsvToSequenceFile iris-data iris-seq
这就是我的java文件的样子
public class CsvToSequenceFile {
public static void main(String[] args) throws IOException,
InterruptedException, ClassNotFoundException {
String inputPath = args[0];
String outputPath = args[1];
Configuration conf = new Configuration();
Job job = new Job(conf);
job.setJobName("Csv to SequenceFile");
job.setJarByClass(Mapper.class);
job.setMapperClass(Mapper.class);
job.setReducerClass(Reducer.class);
job.setNumReduceTasks(0);
job.setOutputKeyClass(LongWritable.class);
job.setOutputValueClass(VectorWritable.class);
job.setOutputFormatClass(SequenceFileOutputFormat.class);
job.setInputFormatClass(TextInputFormat.class);
TextInputFormat.addInputPath(job, new Path(inputPath));
SequenceFileOutputFormat.setOutputPath(job, new Path(outputPath));
// submit and wait for completion
job.waitForCompletion(true);
}
}
这是命令行中的错误
2/10/30 10:43:32 WARN mapred.JobClient: Use GenericOptionsParser for parsing the arguments. Applications should implement Tool for the same.
12/10/30 10:43:33 INFO input.FileInputFormat: Total input paths to process : 1
12/10/30 10:43:33 INFO util.NativeCodeLoader: Loaded the native-hadoop library
12/10/30 10:43:33 WARN snappy.LoadSnappy: Snappy native library not loaded
12/10/30 10:43:34 INFO mapred.JobClient: Running job: job_201210300947_0005
12/10/30 10:43:35 INFO mapred.JobClient: map 0% reduce 0%
12/10/30 10:43:50 INFO mapred.JobClient: Task Id : attempt_201210300947_0005_m_000000_0, Status : FAILED
java.lang.RuntimeException: java.lang.RuntimeException: java.lang.ClassNotFoundException: org.apache.mahout.math.VectorWritable
at org.apache.hadoop.conf.Configuration.getClass(Configuration.java:899)
at org.apache.hadoop.mapred.JobConf.getOutputValueClass(JobConf.java:929)
at org.apache.hadoop.mapreduce.JobContext.getOutputValueClass(JobContext.java:145)
at org.apache.hadoop.mapreduce.lib.output.SequenceFileOutputFormat.getRecordWriter(SequenceFileOutputFormat.java:61)
at org.apache.hadoop.mapred.MapTask$NewDirectOutputCollector.<init>(MapTask.java:628)
at org.apache.hadoop.mapred.MapTask.runNewMapper(MapTask.java:753)
at org.apache.hadoop.mapred.MapTask.run(MapTask.java:370)
at org.apache.hadoop.mapred.Child$4.run(Child.java:255)
at java.security.AccessController.doPrivileged(Native Method)
at javax.security.auth.Subject.doAs(Subject.java:415)
at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1121)
at org.apache.hadoop.mapred.Child.main(Child.java:249)
Caused by: java.lang.RuntimeException: java.lang.ClassNotFoundException: org.apache.mahout.math.VectorWritable
at org.apache.hadoop.conf.Configuration.getClass(Configuration.java:867)
at org.apache.hadoop.conf.Configuration.getClass(Configuration.java:891)
... 11 more
任何想法如何解决这个问题，或者我什至试图正确地完成这个过程？我是 hadoop 和 mahout 的新手，所以如果我正在做一些困难的事情，请告诉我。谢谢！