tdsasciiinputstream.java

Java写的TDS协议(JDBC/ODBC)实现

//
// Copyright 1998 CDS Networks, Inc., Medford Oregon
//
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//      This product includes software developed by CDS Networks, Inc.
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package net.sourceforge.jtds.jdbc;

import java.io.*;


/**
 * Extend the java.io.InputStream class for the TDS driver.
 * <p>
 * This class is used the the <code>getAsciiStream</code>
 * of the <A href=ResultSet.html#getAsciiStream>ResultSet</A> class.
 * <p>
 * The current implementation reads the entire column of data into a 
 * String.  This limits the maximum BLOB size to the largest BLOB 
 * that will fit in memory.
 *
 * @author Craig Spannring
 * @version  $Id: TdsAsciiInputStream.java,v 1.1 2002/10/14 10:48:59 alin_sinpalean Exp $
 */
class TdsAsciiInputStream extends java.io.InputStream
{
   public static final String cvsVersion = "$Id: TdsAsciiInputStream.java,v 1.1 2002/10/14 10:48:59 alin_sinpalean Exp $";

   // The data that will be read from the stream.
   String   data;

   // next is the index into data of the next byte of data in the stream
   int      next = 0;

   public TdsAsciiInputStream(String data_)
   {
      data = data_;
      next = 0;
   }


   public String getData()
   {
      return data;
   }


   public String toString()
   {
      return getData();
   }


   public int read()
      throws java.io.IOException
   {
      int   result;

      if (data == null)
      {
         throw new java.io.IOException("stream was null");
      }
      else if (next == data.length())
      {
         result = -1;
      }
      else
      {
         result = data.charAt(next);
         next++;
      }
      return result;
   }
}