/*

  The contents of this file are subject to the Mozilla Public License Version 1.1

  (the "License"); you may not use this file except in compliance with the License.

  You may obtain a copy of the License at http://www.mozilla.org/MPL/

  Software distributed under the License is distributed on an "AS IS" basis,

  WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License for the

  specific language governing rights and limitations under the License.

  The Original Code is "Hl7DecoderReader.java".  Description:

  ""

  The Initial Developer of the Original Code is University Health Network. Copyright (C)

  2013.  All Rights Reserved.

  Contributor(s): ______________________________________.

  Alternatively, the contents of this file may be used under the terms of the

  GNU General Public License (the "GPL"), in which case the provisions of the GPL are

  applicable instead of those above.  If you wish to allow use of your version of this

  file only under the terms of the GPL and not to allow others to use your version

  of this file under the MPL, indicate your decision by deleting  the provisions above

  and replace  them with the notice and other provisions required by the GPL License.

  If you do not delete the provisions above, a recipient may use your version of

  this file under either the MPL or the GPL.

  */

 package ca.uhn.hl7v2.llp;

 import java.io.BufferedInputStream;

 import java.io.IOException;

 import java.io.InputStream;

 import java.nio.charset.Charset;

 import static ca.uhn.hl7v2.llp.MllpConstants.CHARSET_KEY;

 /**

  * Abstract base class for a HL7Reader that uses a Decoder

  */

 abstract class Hl7DecoderReader<T extends MllpDecoder> implements HL7Reader {

     private InputStream in;

     private T decoder;

     private Charset charset;

     public Hl7DecoderReader() throws IOException {

         decoder = initDecoder();

     }

     public Hl7DecoderReader(InputStream in) throws IOException {

         setInputStream(in);

         decoder = initDecoder();

     }

     public Hl7DecoderReader(InputStream in, Charset charset) throws IOException {

         setInputStream(in);

         this.charset = charset;

         this.decoder = initDecoder();

     }

     protected abstract T initDecoder();

     protected Charset getCharset() {

         if (charset == null) {

             String charsetString = System.getProperty(CHARSET_KEY, "US-ASCII");

             if (charsetString.equals("default")) {

                 charset = Charset.defaultCharset();

             } else {

                 charset = Charset.forName(charsetString);

             }

         }

         return charset;

     }

     public void setInputStream(InputStream in) throws IOException {

         if (in == null) throw new NullPointerException("InputStream is null");

         this.in = new BufferedInputStream(in);

     }

     public void close() throws IOException {

         if (in != null) in.close();

     }

     public String getMessage() throws IOException, LLPException {

         return decoder.getMessage(in);

     }

     protected T getDecoder() {

         return decoder;

     }

 }