content: /*
   * © 2016 AgNO3 Gmbh & Co. KG
   * 
   * This library is free software; you can redistribute it and/or
   * modify it under the terms of the GNU Lesser General Public
   * License as published by the Free Software Foundation; either
   * version 2.1 of the License, or (at your option) any later version.
   * 
   * This library is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   * Lesser General Public License for more details.
   * 
   * You should have received a copy of the GNU Lesser General Public
   * License along with this library; if not, write to the Free Software
   * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
   */
  package jcifs.util;
  
  
  import java.io.UnsupportedEncodingException;
  import java.nio.charset.Charset;
  
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import jcifs.Configuration;
  import jcifs.RuntimeCIFSException;
  
  
  /**
   * @author mbechler
   *
   */
  public final class Strings {
  
      private static final Logger log = LoggerFactory.getLogger(Strings.class);
  
      private static final Charset UNI_ENCODING = Charset.forName("UTF-16LE");
      private static final Charset ASCII_ENCODING = Charset.forName("US-ASCII");
  
  
      /**
       * 
       */
      private Strings () {}
  
  
      /**
       * 
       * @param str
       * @param encoding
       * @return encoded
       */
      public static byte[] getBytes ( String str, Charset encoding ) {
          if ( str == null ) {
              return new byte[0];
          }
          return str.getBytes(encoding);
      }
  
  
      /**
       * 
       * @param str
       * @return the string as bytes (UTF16-LE)
       */
      public static byte[] getUNIBytes ( String str ) {
          return getBytes(str, UNI_ENCODING);
      }
  
  
      /**
       * 
       * @param str
       * @return the string as bytes (ASCII)
       */
      public static byte[] getASCIIBytes ( String str ) {
          return getBytes(str, ASCII_ENCODING);
      }
  
  
      /**
       * @param str
       * @param config
       * @return the string as bytes
       */
      public static byte[] getOEMBytes ( String str, Configuration config ) {
          if ( str == null ) {
              return new byte[0];
          }
          try {
              return str.getBytes(config.getOemEncoding());
          }
          catch ( UnsupportedEncodingException e ) {
              throw new RuntimeCIFSException("Unsupported OEM encoding " + config.getOemEncoding(), e);
          }
      }
  
  
      /**
       * @param src
       * @param srcIndex
       * @param len
       * @return decoded string
       */
      public static String fromUNIBytes ( byte[] src, int srcIndex, int len ) {
          return new String(src, srcIndex, len, UNI_ENCODING);
      }
  
  
      /**
       * @param buffer
       * @param bufferIndex
       * @param maxLen
       * @return position of terminating null bytes
       */
      public static int findUNITermination ( byte[] buffer, int bufferIndex, int maxLen ) {
          int len = 0;
          while ( buffer[ bufferIndex + len ] != (byte) 0x00 || buffer[ bufferIndex + len + 1 ] != (byte) 0x00 ) {
              len += 2;
              if ( len > maxLen ) {
                  if ( log.isDebugEnabled() ) {
                      log.warn("Failed to find string termination with max length " + maxLen);
                      log.debug(Hexdump.toHexString(buffer, bufferIndex, len));
                  }
                  throw new RuntimeCIFSException("zero termination not found");
              }
          }
          return len;
      }
  
  
      /**
       * @param src
       * @param srcIndex
       * @param len
       * @param config
       * @return decoded string
       */
      public static String fromOEMBytes ( byte[] src, int srcIndex, int len, Configuration config ) {
          try {
              return new String(src, srcIndex, len, config.getOemEncoding());
          }
          catch ( UnsupportedEncodingException e ) {
              throw new RuntimeCIFSException("Unsupported OEM encoding " + config.getOemEncoding(), e);
          }
      }
  
  
      /**
       * @param buffer
       * @param bufferIndex
       * @param maxLen
       * @return position of terminating null byte
       */
      public static int findTermination ( byte[] buffer, int bufferIndex, int maxLen ) {
          int len = 0;
          while ( buffer[ bufferIndex + len ] != (byte) 0x00 ) {
              len++;
              if ( len > maxLen ) {
                  throw new RuntimeCIFSException("zero termination not found");
              }
          }
          return len;
      }
  }
  