Hive, How to package the custom java UDF to jar file?

Question

I'm writing a Hive UDF in java. then, as the tutorial says, I have to package it as a jar file.

import org.apache.hadoop.hive.ql.exec.UDAF;
import org.apache.hadoop.hive.ql.exec.UDAFEvaluator;
import org.apache.hadoop.io.IntWritable;

public class Maximum extends UDAF {
  public static class MaximumIntUDAFEvaluator implements UDAFEvaluator{
    private IntWritable result;

    public void init(){
      result = null;
    }
    public boolean iterate(IntWritable value){
      if (value == null){
        return true;
      }
      if ( result == null){
        result = new IntWritable(value.get());
      }else {
        result.set(Math.max(result.get(), value.get()));
      }
      return true;
    }
    public IntWritable terminatePartiaal(){
      return result;
    }

    public boolean merge(IntWritable other){
      return iterate(other);
    }
    public IntWritable terminate(){
      return result;
    }
  }
}

My question is, how to package it to a jar file. I'm a newbie in Java. From what I researched was to use maven to package, but I'm not familiar with that. Can anyone give me suggestion? Thanks a lot!