Interface ByteStreamWriter

  • All Known Implementing Classes:
    ByteBufferByteStreamWriter

    public interface ByteStreamWriter
    A class that can be used to set a byte array parameter by writing to an OutputStream.

    The intended use case is wanting to write data to a byte array parameter that is stored off heap in a direct memory pool or in some other form that is inconvenient to assemble into a single heap-allocated buffer.

    Users should write their own implementation depending on the original data source. The driver provides a built-in implementation supporting the ByteBuffer class, see ByteBufferByteStreamWriter.

    Intended usage is to simply pass in an instance using PreparedStatement.setObject(int, Object):

         int bufLength = someBufferObject.length();
         preparedStatement.setObject(1, new MyByteStreamWriter(bufLength, someBufferObject));
     

    The length must be known ahead of the stream being written to.

    This provides the application more control over memory management than calling PreparedStatement.setBinaryStream(int, InputStream) as with the latter the caller has no control over the buffering strategy.

    • Method Detail

      • getLength

        int getLength()
        Returns the length of the stream.

        This must be known ahead of calling writeTo(ByteStreamTarget).

        Returns:
        the number of bytes in the stream.
      • writeTo

        void writeTo​(ByteStreamWriter.ByteStreamTarget target)
              throws java.io.IOException
        Write the data to the provided OutputStream.

        Should not write more than getLength() bytes. If attempted, the provided stream will throw an IOException.

        Parameters:
        target - the stream to write the data to
        Throws:
        java.io.IOException - if the underlying stream throws or there is some other error.