com.sun.xml.ws.api.pipe
Interface Codec

All Known Subinterfaces:
EndpointAwareCodec, RootOnlyCodec, SOAPBindingCodec, StreamSOAPCodec
All Known Implementing Classes:
MimeCodec, MtomCodec, SOAPBindingCodec, StreamSOAP11Codec, StreamSOAP12Codec, StreamSOAPCodec, SwACodec, XMLCodec, XMLHTTPBindingCodec

public interface Codec

Encodes a Message (its XML infoset and attachments) to a sequence of bytes.

This interface provides pluggability for different ways of encoding XML infoset, such as plain XML (plus MIME attachments), XOP, and FastInfoset.

Transport usually needs a MIME content type of the encoding, so the Codec interface is designed to return this information. However, for some encoding (such as XOP), the encoding may actually change based on the actual content of Message, therefore the codec returns the content type as a result of encoding.

Codec does not produce transport-specific information, such as HTTP headers.

Codec is a non-reentrant object, meaning no two threads can concurrently invoke the decode method. This allows the implementation to easily reuse parser objects (as instance variables), which are costly otherwise.

BindingID determines the Codec. See BindingID.createEncoder(WSBinding).

See Also:
EndpointAwareCodec

Method Summary
 Codec copy()
          Creates a copy of this Codec.
 void decode(InputStream in, String contentType, Packet response)
          Reads bytes from InputStream and constructs a Message.
 void decode(ReadableByteChannel in, String contentType, Packet response)
           
 ContentType encode(Packet packet, OutputStream out)
          Encodes an XML infoset portion of the Message (from <soap:Envelope> to </soap:Envelope>).
 ContentType encode(Packet packet, WritableByteChannel buffer)
          The version of encode(Packet,OutputStream) that writes to NIO ByteBuffer.
 String getMimeType()
          Get the MIME type associated with this Codec.
 ContentType getStaticContentType(Packet packet)
          If the MIME content-type of the encoding is known statically then this method returns it.
 

Method Detail

getMimeType

String getMimeType()
Get the MIME type associated with this Codec.

If available the MIME type will represent the media that the codec encodes and decodes. The MIME type returned will be the most general representation independent of an instance of this MIME type utilized as a MIME content-type.

Returns:
null if the MIME type can't be determined by the Codec implementation. Otherwise the MIME type is returned.

getStaticContentType

ContentType getStaticContentType(Packet packet)
If the MIME content-type of the encoding is known statically then this method returns it.

Transports often need to write the content type before it writes the message body, and since the encode method returns the content type after the body is written, it requires a buffering. For those Codecs that always use a constant content type, This method allows a transport to streamline the write operation.

Returns:
null if the content-type can't be determined in short of encodin the packet. Otherwise content type for this Packet, such as "application/xml".

encode

ContentType encode(Packet packet,
                   OutputStream out)
                   throws IOException
Encodes an XML infoset portion of the Message (from <soap:Envelope> to </soap:Envelope>).

Internally, this method is most likely invoke Message.writeTo(XMLStreamWriter) to turn the message into infoset.

Parameters:
packet -
out - Must not be null. The caller is responsible for closing the stream, not the callee.
Returns:
The MIME content type of the encoded message (such as "application/xml"). This information is often ncessary by transport.
Throws:
IOException - if a OutputStream throws IOException.

encode

ContentType encode(Packet packet,
                   WritableByteChannel buffer)
The version of encode(Packet,OutputStream) that writes to NIO ByteBuffer.

TODO: for the convenience of implementation, write an adapter that wraps WritableByteChannel to OutputStream.


copy

Codec copy()
Creates a copy of this Codec.

Since Codec instance is not re-entrant, the caller who needs to encode two Messages simultaneously will want to have two Codec instances. That's what this method produces.

Implentation Note

Note that this method might be invoked by one thread while another thread is executing one of the encode(com.sun.xml.ws.api.message.Packet, java.io.OutputStream) methods. This should be OK because you'll be only copying things that are thread-safe, and creating new ones for thread-unsafe resources, but please let us know if this contract is difficult.

Returns:
always non-null valid Codec that performs the encoding work in the same way --- that is, if you copy an FI codec, you'll get another FI codec.

Once copied, two Codecs may be invoked from two threads concurrently; therefore, they must not share any state that requires isolation (such as temporary buffer.)

If the Codec implementation is already re-entrant and multi-thread safe to begin with, then this method may simply return this.


decode

void decode(InputStream in,
            String contentType,
            Packet response)
            throws IOException
Reads bytes from InputStream and constructs a Message.

The design encourages lazy decoding of a Message, where a Message is returned even before the whole message is parsed, and additional parsing is done as the Message body is read along. A Codec is most likely have its own implementation of Message for this purpose.

Parameters:
in - the data to be read into a Message. The transport would have read any transport-specific header before it passes an InputStream, and InputStream is expected to be read until EOS. Never null.

Some transports, such as SMTP, may 'encode' data into another format (such as uuencode, base64, etc.) It is the caller's responsibility to 'decode' these transport-level encoding before it passes data into Codec.

contentType - The MIME content type (like "application/xml") of this byte stream. Thie text includes all the sub-headers of the content-type header. Therefore, in more complex case, this could be something like multipart/related; boundary="--=_outer_boundary"; type="multipart/alternative". This parameter must not be null.
response - The parsed Message will be set to this Packet. Codec may add additional properties to this Packet. On a successful method completion, a Packet must contain a Message.
Throws:
IOException - if InputStream throws an exception.

decode

void decode(ReadableByteChannel in,
            String contentType,
            Packet response)
See Also:
decode(InputStream, String, Packet)