Ytukyg

Im trying to write java MapReduce code and keep getting the error:

Error: java.lang.NumberFormatException: For input string: "time"

at java.lang.NumberFormatException.forInputString(NumberFormatException.java:65)

at java.lang.Long.parseLong(Long.java:589)

at java.lang.Long.parseLong(Long.java:631)

at TokenizerMapper.map(Unknown Source)

at TokenizerMapper.map(Unknown Source)

at org.apache.hadoop.mapreduce.Mapper.run(Mapper.java:145)

at org.apache.hadoop.mapred.MapTask.runNewMapper(MapTask.java:793)

at org.apache.hadoop.mapred.MapTask.run(MapTask.java:341)

at org.apache.hadoop.mapred.YarnChild$2.run(YarnChild.java:164)

at java.security.AccessController.doPrivileged(Native Method)

at javax.security.auth.Subject.doAs(Subject.java:422)

at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1917)

at org.apache.hadoop.mapred.YarnChild.main(YarnChild.java:158)

The mapper code in question is the following

    public class TokenizerMapper extends Mapper<Object, Text, Text, IntWritable> {

    private final IntWritable one = new IntWritable(1);

    private Text data = new Text();

    String transactionData = new String[5];



    public void map(Object key, Text value, Context context) throws IOException, InterruptedException {





        StringTokenizer itr = new StringTokenizer(value.toString(), ",");





        while (itr.hasMoreTokens()) {



            for (int i = 0; i < 5; i++) {

                transactionData[i] = itr.nextToken();

            }





            Long timestamp = Long.parseLong(transactionData[2]);

            Instant instant = Instant.ofEpochSecond(timestamp);

            LocalDateTime ldt = LocalDateTime.ofInstant(instant, ZoneId.of("GMT"));

            int year = ldt.getYear(); //e.g 2009

            Month month = ldt.getMonth(); //e.g JANUARY



            String time = month.toString() + ":" + Integer.toString(year);



            data.set(time);



            context.write(data, one);

        }

    }

}

It is supposed to take the 3rd value in each line of a csv dataset, which is a number, convert this to string, convert that to long and use the long to find the month and year.

where am i going wrong? thanks.

edit// Sample entry:

0e3e2357e806b6cdb1f70b54c3a3a17b6714ee1f0e68bebb44a74b1efd512098,00000000839a8e6886ab5951d76f411475428afc90947ee320161bbf18eb6048,1231469665,1,1

If the problem is a header, just replace the line that causes the problem:

Long timestamp = Long.parseLong(transactionData[2]);

with

Long timestamp = 0L;

try {

    timestamp = Long.parseLong(transactionData[2]);

} catch (NumberFormatException e) {

    return;

}

So if the value is invalid the method will terminate without crashing.