Package com.sun.xml.ws.encoding

Class MIMEPartStreamingDataHandler

  • All Implemented Interfaces:
    Transferable, Closeable, AutoCloseable
    public class MIMEPartStreamingDataHandler
extends StreamingDataHandler
    Implementation of StreamingDataHandler to access MIME attachments efficiently. Applications can use the additional methods and decide on how to access the attachment data in JAX-WS applications.

    for e.g.: DataHandler dh = proxy.getData(); StreamingDataHandler sdh = (StreamingDataHandler)dh; // readOnce() doesn't store attachment on the disk in some cases // for e.g when only one huge attachment after soap envelope part in MIME message InputStream in = sdh.readOnce(); ... in.close(); sdh.close();

    Author:
    Jitendra Kotamraju

    • Constructor Detail

      • MIMEPartStreamingDataHandler

        public MIMEPartStreamingDataHandler​(MIMEPart part)

    • Method Detail

      • readOnce

        public InputStream readOnce()
                     throws IOException
        Description copied from class: StreamingDataHandler
        Works like DataHandler.getInputStream() except that this method can be invoked only once.

        This is used as a signal from the caller that there will be no further DataHandler.getInputStream() invocation nor StreamingDataHandler.readOnce() invocation on this object (which would result in IOException.)

        When DataHandler is backed by a streaming BLOB (such as an attachment in a web service read from the network), this allows the callee to avoid unnecessary buffering.

        Note that it is legal to call DataHandler.getInputStream() multiple times and then call StreamingDataHandler.readOnce() afterward. Streams created such a way can be read in any order — there's no requirement that streams created earlier must be read first.

        Specified by:
        readOnce in class StreamingDataHandler
        Returns:
        always non-null. Represents the content of this BLOB. The returned stream is generally not buffered, so for better performance read in a big batch or wrap this into BufferedInputStream.
        Throws:
        IOException - if any i/o error

      • moveTo

        public void moveTo​(File file)
            throws IOException
        Description copied from class: StreamingDataHandler
        Obtains the BLOB into a specified file.

        Semantically, this method is roughly equivalent to the following code, except that the actual implementation is likely to be a lot faster. 

         InputStream i = getInputStream();
 OutputStream o = new FileOutputStream(dst);
 int ch;
 while((ch=i.read())!=-1)  o.write(ch);
 i.close();
 o.close();

        The main motivation behind this method is that often DataHandler that reads data from a streaming source will use a temporary file as a data store to hold data (think of commons-fileupload.) In such case this method can be as fast as calling File.renameTo(File).

        This method shouldn't be called when there are any open streams.

        After this method is invoked, StreamingDataHandler.readOnce() and DataHandler.getInputStream() will simply open the destination file you've specified as an argument. So if you further move the file or delete this file, those methods will behave in undefined fashion. For a simliar reason, calling this method multiple times will cause undefined behavior.

        Specified by:
        moveTo in class StreamingDataHandler
        Throws:
        IOException