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MapReduce, mail # user - Re: SequenceFileReadDemo issue


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Re: SequenceFileReadDemo issue
saurabh chhajed 2013-09-16, 02:35
Hi,

Can you look at this please, this might help you --

http://svn.apache.org/viewvc/hadoop/common/trunk/hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/io/TestSequenceFile.java?view=markup
Thanks,

On Mon, Sep 16, 2013 at 7:48 AM, kun yan <[EMAIL PROTECTED]> wrote:

> Hi all when i read  SequenceFIle occur exception
>
> Exception in thread "main" java.lang.RuntimeException:
> java.lang.NoSuchMethodException:
> org.apache.hadoop.io.SequenceFile$Reader.<init>()
>  at
> org.apache.hadoop.util.ReflectionUtils.newInstance(ReflectionUtils.java:128)
> at
> com.yanbit.hadoop.filesystem.sequence.SequenceFileReadDemo.main(SequenceFileReadDemo.java:24)
> Caused by: java.lang.NoSuchMethodException:
> org.apache.hadoop.io.SequenceFile$Reader.<init>()
> at java.lang.Class.getConstructor0(Unknown Source)
>  at java.lang.Class.getDeclaredConstructor(Unknown Source)
> at
> org.apache.hadoop.util.ReflectionUtils.newInstance(ReflectionUtils.java:122)
>  ... 1 more
>
> follow is my source code
>
> public class SequenceFileReadDemo {
>     public static void main(String[] args) throws IOException {
>  String uri = args[0];// /sequence/sequencefile
> Configuration conf = new Configuration();
> conf.set("fs.defaultFS", "hdfs://hydra0001:8020");
>  FileSystem fs = FileSystem.get(conf);
> Path path = new Path(uri);
> SequenceFile.Reader reader = null;
>
> try {
>     reader = new SequenceFile.Reader(fs, path, conf);
>     Writable key = (Writable) ReflectionUtils.newInstance(
>      reader.getClass(), conf);
>     Writable value = (Writable) ReflectionUtils.newInstance(
>      reader.getValueClass(), conf);
>     long position = reader.getPosition();
>     while (reader.next(key,value)) {
>         String syncSeen = reader.syncSeen() ? "*" : "";
>         System.out.printf("[%s%s]\t%s\t%s\n",  position,  syncSeen,  key,
>  value);
>         position = reader.getPosition(); // beginning of next record
>     }
> } finally {
>     IOUtils.closeStream(reader);
>  }
>     }
> }
>
> --
>
> In the Hadoop world, I am just a novice, explore the entire Hadoop
> ecosystem, I hope one day I can contribute their own code
>
> YanBit
> [EMAIL PROTECTED]
>
>