import java.io.FileOutputStream;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLConnection;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.TimeZone;
import javax.crypto.Mac;
import javax.crypto.spec.SecretKeySpec;
import org.apache.cxf.common.util.Base64Utility;

public class PDF_Alchemy_Download {
  private static final String ACCESS_KEY_ID="xxxxxxxxxxxxxxxxxxxx";
  private static final String SECRET_ACCESS_KEY="xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx";
  private static final String HMAC_SHA1="HMACSHA1";

  // Downloads the next document from PDF Alchemy.
  // Returns the documentId on success, or null on failure.
  private static String downloadNext() {
    try {
      // Generate the HMAC-SHA1 signature.
      SimpleDateFormat dateFormat=new SimpleDateFormat("EEE, dd MMM yyyy HH:mm:ss 'GMT'");
      dateFormat.setTimeZone(TimeZone.getTimeZone("GMT"));
      String date=dateFormat.format(new Date());
      String request='/'+ACCESS_KEY_ID+"/outqueue/next";
      String clearText="GET\n"+ACCESS_KEY_ID+'\n'+date+'\n'+request;
      Mac mac = Mac.getInstance(HMAC_SHA1);
      mac.init(new SecretKeySpec(SECRET_ACCESS_KEY.getBytes(),HMAC_SHA1));
      String signature=Base64Utility.encode(mac.doFinal(clearText.getBytes()));

      // Request the next document from PDF Alchemy.
      URLConnection conn=(new URL("http://www.pdfalchemy.com"+request)).openConnection();
      conn.setRequestProperty("date",date);
      conn.setRequestProperty("X-PDF-Alchemy-Signature",signature);

      // Receive the binary data, and write it to file.
      InputStream inStream=conn.getInputStream();
      String filename=conn.getHeaderField("Content-Disposition");
      if (filename.indexOf('"')>0) filename=filename.substring(filename.indexOf('"')+1);
      if (filename.indexOf('"')>0) filename=filename.substring(0,filename.indexOf('"'));
      FileOutputStream fileStream=new FileOutputStream(filename);
      byte buffer[]=new byte[10*1024];
      int bytesRead;
      while ((bytesRead=inStream.read(buffer))>=0)
        fileStream.write(buffer,0,bytesRead);
      fileStream.close();
      inStream.close();
      System.out.println("Downloaded '"+filename+"'.");

      // Return the PDF Alchemy document ID.
      return conn.getHeaderField("X-PDF-Alchemy-ID");
    } catch (Exception e) {
      System.out.println(e.toString());
    }
    return null;
  }

  // Removes documentId from the PDF Alchemy outqueue.
  private static void deleteDocument(String documentId) {
    try {
      // Generate the HMAC-SHA1 signature.
      SimpleDateFormat dateFormat=new SimpleDateFormat("EEE, dd MMM yyyy HH:mm:ss 'GMT'");
      dateFormat.setTimeZone(TimeZone.getTimeZone("GMT"));
      String date=dateFormat.format(new Date());
      String request='/'+ACCESS_KEY_ID+"/outqueue/"+documentId;
      String clearText="DELETE\n"+ACCESS_KEY_ID+'\n'+date+'\n'+request;
      Mac mac = Mac.getInstance(HMAC_SHA1);
      mac.init(new SecretKeySpec(SECRET_ACCESS_KEY.getBytes(),HMAC_SHA1));
      String signature=Base64Utility.encode(mac.doFinal(clearText.getBytes()));

      // Remove the document from PDF Alchemy.
      HttpURLConnection conn=(HttpURLConnection)((new URL("http://www.pdfalchemy.com"+request)).openConnection());
      conn.setRequestMethod("DELETE");
      conn.setRequestProperty("date",date);
      conn.setRequestProperty("X-PDF-Alchemy-Signature",signature);
      conn.getInputStream().close();
      System.out.println("Removed '"+documentId+"' from PDF Alchemy.");
    } catch (Exception e) {
      System.out.println(e.toString());
    }
  }

  public static void main(String[] args) {
    String documentId;
    while ((documentId=downloadNext())!=null)
      deleteDocument(documentId);
  }

}