discoveryresponse.java

jxta_src_2.41b jxta 2.41b 最新版源码 from www.jxta.org

            }
        }

        try {
            while (advs.hasMoreElements()) {
                Long l = (Long) exps.nextElement();
                Object response = advs.nextElement();

                if (response instanceof InputStream) {
                    e = adv.createElement(responsesTag, streamToString((InputStream) response));
                } else {
                    e = adv.createElement(responsesTag, response.toString());
                }
                adv.appendChild(e);
                if (adv instanceof Attributable) {
                    ((Attributable) e).addAttribute(expirationTag, l.toString());
                }
            }
        } catch (Exception failed) {
            if (LOG.isEnabledFor(Level.WARN)) {
                LOG.warn("Got an Exception during doc creation", failed);
            }
            IllegalStateException failure = new IllegalStateException("Got an Exception during doc creation");
            failure.initCause(failed);
            throw failure;
        }
        return adv;
    }

    /**
     *  Description of the Method
     */
    private void parseAdvertisements() {

        List advertisements = new ArrayList();

        Enumeration eachResponse = getResponses();

        while (eachResponse.hasMoreElements()) {
            Object response = eachResponse.nextElement();

            if (response instanceof String) {
                String str = (String) response;
                try {
                    Advertisement adv = (Advertisement)
                                        AdvertisementFactory.newAdvertisement(MimeMediaType.XMLUTF8, new StringReader(str));
                    advertisements.add(adv);
                } catch (Exception e) {
                    if (LOG.isEnabledFor(Level.DEBUG)) {
                        LOG.debug("No advertisements in response element", e);
                    }
                }
            } else
                if (response instanceof InputStream) {
                    InputStream is = (InputStream) response;
                    try {
                        Advertisement adv = (Advertisement)
                                            AdvertisementFactory.newAdvertisement(MimeMediaType.XMLUTF8, is);
                        advertisements.add(adv);
                    } catch (Exception e) {
                        if (LOG.isEnabledFor(Level.WARN)) {
                            LOG.warn("Can not parse Response", e);
                        }
                    }
                } else {
                    if (LOG.isEnabledFor(Level.WARN)) {
                        LOG.warn("Can not parse Response of type " + response.getClass().getName());
                    }
                }
        }
        setAdvertisements(advertisements);
    }

    /**
     *  Parses a document into this object
     *
     *@param  doc  Document
     */
    private void readIt(TextElement doc) {
        Vector res = new Vector();
        Vector exps = new Vector();

        try {
            Enumeration elements = doc.getChildren();
            while (elements.hasMoreElements()) {
                TextElement elem = (TextElement) elements.nextElement();
                if (elem.getName().equals(typeTag)) {
                    type = Integer.parseInt(elem.getTextValue());
                    continue;
                }

                if (elem.getName().equals(peerAdvTag)) {
                    String peerString = elem.getTextValue();

                    if(null == peerString) {
                        continue;
                    }

                    peerString = peerString.trim();
                    if(peerString.length() > 0) {
                        setPeerAdvertisement((PeerAdvertisement)
                                              AdvertisementFactory.newAdvertisement(MimeMediaType.XMLUTF8, new StringReader(elem.getTextValue())));
                    }
                    continue;
                }

                if (elem.getName().equals(queryAttrTag)) {
                    setQueryAttr(elem.getTextValue());
                    continue;
                }

                if (elem.getName().equals(queryValueTag)) {
                    setQueryValue(elem.getTextValue());
                    continue;
                }

                if (elem.getName().equals(responsesTag)) {
                    // get the response
                    String aResponse = elem.getTextValue();

                    if (null == aResponse) {
                        if (LOG.isEnabledFor(Level.DEBUG)) {
                            LOG.debug("Discarding an empty response tag");
                        }
                        continue;
                    }
                    res.add(aResponse);

                    long exp;
                    // get expiration associated with this response
                    if(elem instanceof Attributable) {
                        Attribute attr = ((Attributable) elem).getAttribute(expirationTag);

                        if (null != attr) {
                            exp = Long.parseLong(attr.getValue());
                        } else {
                            // if there are no attribute use DEFAULT_EXPIRATION
                            if (LOG.isEnabledFor(Level.DEBUG)) {
                                LOG.debug("Received an old-style DiscoveryResponse.\n " +
                                          "You received a response from a peer that does \n" +
                                          "not support advertisement aging. \n" +
                                          "Setting expiration to DiscoveryService.DEFAULT_EXPIRATION ");
                            }
                            exp = DiscoveryService.DEFAULT_EXPIRATION;
                        }
                    } else {
                        exp = DiscoveryService.DEFAULT_EXPIRATION;
                    }

                    exps.add(new Long(exp));
                }
            }
        } catch (Exception failed) {
            if (LOG.isEnabledFor(Level.WARN)) {
                LOG.warn("Got an Exception during Parse ", failed);
            }
            IllegalArgumentException failure = new IllegalArgumentException("Got an Exception during parse");
            failure.initCause(failed);
            throw failure;
        }
        setResponses(res);
        setExpirations(exps);
    }


    /**
     *  Reads in a stream into a string
     *
     *@param  is  inputstream
     *@return     string representation of a stream
     */
    private String streamToString(InputStream is) {
        StringBuffer stw = new StringBuffer();
        Reader reader = null;
        try {
            reader = new InputStreamReader(is, "UTF-8");
        } catch (UnsupportedEncodingException uee) {
            if (LOG.isEnabledFor(Level.DEBUG)) {
                LOG.debug("InputStreamReader creation error", uee);
            }
        }
        char[] buf = new char[512];

        try {
            do {
                int c = reader.read(buf);
                if (c == -1) {
                    break;
                }
                stw.append(buf, 0, c);
            } while (true);
        } catch (IOException ie) {
            if (LOG.isEnabledFor(Level.WARN)) {
                LOG.warn("Got an Exception during stream conversion", ie);
            }
            return null;
        } finally {
            try {
                is.close();
            } catch (IOException ignored) {}
        }

        return stw.toString();
    }

    /**
     * {@inheritDoc}
     */
    public String toString() {

        try {
            StructuredTextDocument doc = (StructuredTextDocument) getDocument(MimeMediaType.XMLUTF8);
            return doc.toString();
        } catch (Throwable e) {
            if (e instanceof Error) {
                throw (Error) e;
            } else
                if (e instanceof RuntimeException) {
                    throw (RuntimeException) e;
                } else {
                    throw new UndeclaredThrowableException(e);
                }
        }
    }
}