Reverse complement of DNA sequence

This source code is run in the example that determines the reverse complement of a DNA sequence.

```java import org.biojava.bio.seq.impl.RevCompSequence; import org.biojavax.bio.seq.RichSequence; import org.biojavax.bio.seq.RichSequenceIterator; import org.biojavax.bio.seq.io.FastaFormat; import org.biojavax.bio.seq.io.FastaHeader;

import java.io.BufferedReader; import java.io.FileReader;

public class RevComp {

   public static void main(String[] args) throws Exception {
   
       String fastaLocation;
       if(args.length > 0) {
           fastaLocation = args[0];
       }
       else {
           fastaLocation = "data/revcomp/input.fasta";
       }
       
       long time = System.currentTimeMillis();
       
       FastaHeader fastaHeader = new FastaHeader();
       fastaHeader.setShowAccession(true);
       fastaHeader.setShowDescription(false);
       fastaHeader.setShowIdentifier(false);
       fastaHeader.setShowName(false);
       fastaHeader.setShowNamespace(false);
       fastaHeader.setShowVersion(false);

       FastaFormat fastaFormat = new FastaFormat();
       fastaFormat.setHeader(fastaHeader);
       fastaFormat.setLineWidth(60);

       BufferedReader br = new BufferedReader(new FileReader(fastaLocation));
       RichSequenceIterator iter = RichSequence.IOTools.readFastaDNA(br, null);
       while(iter.hasNext()) {
           RichSequence seq = iter.nextRichSequence();
           RevCompSequence rev = new RevCompSequence(seq);
           rev.setName(seq.getAccession()+" "+seq.getDescription());
           fastaFormat.writeSequence(rev, System.out);
       }
       
       long finalTime = System.currentTimeMillis();
       System.out.println(finalTime-time+" ms");
   }

}

```