Error Messages:
java.lang.Exception: java.lang.ArrayIndexOutOfBoundsException: 1
at org.apache.hadoop.mapred.LocalJobRunner$Job.runTasks(LocalJobRunner.java:492)
at org.apache.hadoop.mapred.LocalJobRunner$Job.run(LocalJobRunner.java:552)
Caused by: java.lang.ArrayIndexOutOfBoundsException: 1
at exper.Filter$Map.map(Filter.java:25)
at exper.Filter$Map.map(Filter.java:19)
at org.apache.hadoop.mapreduce.Mapper.run(Mapper.java:146)
at org.apache.hadoop.mapred.MapTask.runNewMapper(MapTask.java:799)
at org.apache.hadoop.mapred.MapTask.run(MapTask.java:347)
at org.apache.hadoop.mapred.LocalJobRunner$Job$MapTaskRunnable.run(LocalJobRunner.java:271)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at java.lang.Thread.run(Thread.java:748)

Reason for error: The source code sets the data separator as space, while the code separator in the dataset is tab tab
Modify the red marked statement.

public void map(Object key, Text value, Context context) throws IOException, InterruptedException {
    String line = value.toString();
    System.out.println(line);
    String arr[] = line.split("\t");
    newKey.set(arr[1]);
    context.write(newKey, NullWritable.get());
    System.out.println(newKey);
}

Then run the jar file on Linux:
enter the command under the folder where the jar package is stored:
Hadoop jar mapreducedemo-1.0-snapshot.jar exp.filter/mymapreduce2/in/buyer_Myfavorite1/user/root/mymapreduce2/out
runs successfully!