Interface AsyncMiddleManServlet.ContentTransformer

    • Method Summary

      All Methods Instance Methods Abstract Methods 
      Modifier and Type Method Description
      void transform​(java.nio.ByteBuffer input, boolean finished, java.util.List<java.nio.ByteBuffer> output)
      Transforms the given input byte buffers into (possibly multiple) byte buffers.
    • Method Detail

      • transform

        void transform​(java.nio.ByteBuffer input,
                       boolean finished,
                       java.util.List<java.nio.ByteBuffer> output)
                throws java.io.IOException

        Transforms the given input byte buffers into (possibly multiple) byte buffers.

        The transformation must happen synchronously in the context of a call to this method (it is not supported to perform the transformation in another thread spawned during the call to this method). The transformation may happen or not, depending on the transformer implementation. For example, a buffering transformer may buffer the input aside, and only perform the transformation when the whole input is provided (by looking at the finished flag).

        The input buffer will be cleared and reused after the call to this method. Implementations that want to buffer aside the input (or part of it) must copy the input bytes that they want to buffer.

        Typical implementations:

         // Identity transformation (no transformation, the input is copied to the output)
         public void transform(ByteBuffer input, boolean finished, List<ByteBuffer> output)
         {
             output.add(input);
         }
        
         // Discard transformation (all input is discarded)
         public void transform(ByteBuffer input, boolean finished, List<ByteBuffer> output)
         {
             // Empty
         }
        
         // Buffering identity transformation (all input is buffered aside until it is finished)
         public void transform(ByteBuffer input, boolean finished, List<ByteBuffer> output)
         {
             ByteBuffer copy = ByteBuffer.allocate(input.remaining());
             copy.put(input).flip();
             store(copy);
        
             if (finished)
             {
                 List<ByteBuffer> copies = retrieve();
                 output.addAll(copies);
             }
         }
         
        Parameters:
        input - the input content to transform (may be of length zero)
        finished - whether the input content is finished or more will come
        output - where to put the transformed output content
        Throws:
        java.io.IOException - in case of transformation failures