我有一个非常简单的"Hello world"风格地图/减少工作.
public class Tester extends Configured implements Tool {
@Override
public int run(String[] args) throws Exception {
if (args.length != 2) {
System.err.printf("Usage: %s [generic options] <input> <output>\n",
getClass().getSimpleName());
ToolRunner.printGenericCommandUsage(System.err);
return -1;
}
Job job = Job.getInstance(new Configuration());
job.setJarByClass(getClass());
getConf().set("mapreduce.job.queuename", "adhoc");
FileInputFormat.addInputPath(job, new Path(args[0]));
FileOutputFormat.setOutputPath(job, new Path(args[1]));
job.setOutputKeyClass(Text.class);
job.setOutputValueClass(NullWritable.class);
job.setMapperClass(TesterMapper.class);
job.setNumReduceTasks(0);
return job.waitForCompletion(true) ? 0 : 1;
}
public static void main(String[] args) throws Exception {
int exitCode = ToolRunner.run(new Tester(), args);
System.exit(exitCode);
}
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它实现了ToolRunner,但是在运行时没有解析参数.
$hadoop jar target/manifold-mapreduce-0.1.0.jar ga.manifold.mapreduce.Tester …Run Code Online (Sandbox Code Playgroud)