contentadvertisementimpl.java

jxta-cms-src-2.4.zip 是官网上的比较稳定的CMS源代码。目前是最稳定的高版本。

     * @param is the InputStream containing the advertisement
     * @exception IllegalArgumentException if the advertisement was invalid
     * @exception IOException if there was an I/O error
     */
    public ContentAdvertisementImpl(InputStream is) throws IOException {

        registerAdvertisement();

        StructuredTextDocument doc = (StructuredTextDocument)
                                     StructuredDocumentFactory.newStructuredDocument(
                                         new MimeMediaType("text", "xml"), is);
        init(doc);
    }

    /**
     * Creates a new ContentAdvertisement from the specified TextElement.
     * @exception IllegalArgumentException if the TextElement was missing data
     * or contained invalid data
     * @exception NullPointerException if te is null
     * @see ContentMetadataFactory
     */
    public ContentAdvertisementImpl(TextElement te) {
        registerAdvertisement();
        init(te);
    }

    // reads advertisement from specified TextElement
    private void init(TextElement root) {
        Vector metadataElems = new Vector();
        if (!root.getName().equals(getAdvertisementType())) {
            throw new IllegalArgumentException(
                "Not a ContentAdvertisement element: " + root.getName());
        }
        Enumeration e = root.getChildren();
        while (e.hasMoreElements()) {
            TextElement te = (TextElement)e.nextElement();
            String s = te.getName();
            String t = te.getTextValue();
            if ((t != null)||(te.getChildren() !=null)) {
                if (s.equals(EN_NAME)) {
                    name = t;
                } else
                    if (s.equals(EN_CID)) {
                        try {
                            cid = new ContentIdImpl(t);
                        } catch (IllegalArgumentException ex) {
                            throw new IllegalArgumentException(
                                "Invalid content id: " + t);
                        }
                    } else
                        if (s.equals(EN_LENGTH)) {
                            try {
                                length = Long.parseLong(t);
                            } catch (NumberFormatException ex) {
                                throw new IllegalArgumentException(
                                    "Invalid content length: " + t);
                            }
                        } else
                            if (s.equals(EN_TYPE)) {
                                type = t;
                            } else
                                if (s.equals(EN_DESCRIPTION)) {
                                    description = t;
                                } else
                                    if (s.equals(EN_METADATA)) {
                                        metadataElems.addElement(ContentMetadataFactory
                                                                 .newInstance(te));
                                    } else
                                        if (s.equals(EN_ADDRESS)) {
                                            address = t;
                                        }
            } else
                if (s.equals(EN_METADATA)) {
                    //a metadata element may have a null value if all of its
                    //information is stored in sub-elements
                    metadataElems.addElement(ContentMetadataFactory
                                             .newInstance(te));
                }
        }
        if (name == null) {
            throw new IllegalArgumentException(
                "Missing required 'name' element");
        }
        if (cid == null) {
            throw new IllegalArgumentException(
                "Missing required 'cid' element");
        }
        if(metadataElems.size() != 0) {
            metadata = new ContentMetadata[metadataElems.size()];
            metadataElems.toArray(metadata);
        }
    }

    /**
     * Returns the advertisement type.
     */
    public static String getAdvertisementType() {
        return "jxta:ContentAdvertisement";
    }

    /**
     * Returns the name of the content.
     */
    public String getName() {
        return name;
    }

    /**
     * Returns the content id.
     */
    public ContentId getContentId() {
        return cid;
    }

    /**
     * Returns the length of the content, or -1 if unknown
     */
    public long getLength() {
        return length;
    }

    /**
     * Returns the mime type of the content, or null if unknown
     */
    public String getType() {
        return type;
    }

    /**
     * Returns the description of the content or null if none.
     */
    public String getDescription() {
        return description;
    }

    /**
     * Returns the metadata describing this content, or null if not specified.
     */
    public ContentMetadata[] getMetadata() {
        return metadata;
    }

    /**
     * Returns the peer id or null if none.
     */
    public String getAddress() {
        return address;
    }

    /**
     * Sets the address of the peer that holds the content.
     */
    public void setAddress(String address) {
        this.address = address;
    }

    /**
     * Returns the document representation of this advertisement.
     */
    public Document getDocument(MimeMediaType mtype) {
        StructuredDocument doc = (StructuredDocument)
                                 StructuredDocumentFactory.newStructuredDocument(
                                     mtype, getAdvertisementType());
        appendElements(doc, doc);
        return doc;
    }

    /**
     * Appends this content advertisement to the specified structured
     * document element.
     */
    public void appendDocument(StructuredDocument doc, Element el) {
        Element e = doc.createElement(getAdvertisementType());
        el.appendChild(e);
        appendElements(doc, e);
    }

    // append elements to specified document element
    private void appendElements(StructuredDocument doc, Element e) {
        e.appendChild(doc.createElement(EN_NAME, name));
        e.appendChild(doc.createElement(EN_CID, cid.toString()));
        if (length != -1) {
            e.appendChild(doc.createElement(EN_LENGTH, Long.toString(length)));
        }
        if (type != null) {
            e.appendChild(doc.createElement(EN_TYPE, type));
        }
        if (description != null) {
            e.appendChild(doc.createElement(EN_DESCRIPTION, description));
        }
        if (metadata != null) {
            for(int a = 0; a < metadata.length; a++) {
                //insert metadata element into doc
                metadata[a].appendDocument(doc, doc);
            }
        }
        if (address != null) {
            e.appendChild(doc.createElement(EN_ADDRESS, address));
        }
    }

    public boolean equals(Object adv) {
        if (LOG.isEnabledFor(Level.DEBUG))
            LOG.debug("ContentAdvertismentImpl.equals("+adv.toString()+") "+toString());
        if (adv instanceof ContentAdvertisementImpl) {
            return toString().equals(((ContentAdvertisementImpl)adv).toString());
        }

        return false;
    }

    /**
     * Returns a string representation of this advertisement.
     */
    public String toString() {
        StringBuffer sb = new StringBuffer();
        sb.append("{name=");
        sb.append(name);
        sb.append(";cid=");
        sb.append(cid.toString());
        if (length != -1) {
            sb.append(";length=");
            sb.append(length);
        }
        if (type != null) {
            sb.append(";type=");
            sb.append(type);
        }
        if (description != null) {
            sb.append(";description=");
            sb.append(description);
        }
        if (metadata != null) {
            sb.append(";metadata=(");
            for(int a = 0; a < metadata.length; a++)
                sb.append(metadata[a] + "|");
            sb.setCharAt(sb.length() - 1, ')');
        }
        if (address != null) {
            sb.append(";address=");
            sb.append(address);
        }
        sb.append('}');
        return sb.toString();
    }

    public static void registerAdvertisement () {

        if (!isRegistered) {
            // make sure that the AdvertisementFactory knows about ContentAdvertisement.
            AdvertisementFactory.Instantiator instantiator = new Instantiator();
            AdvertisementFactory.registerAdvertisementInstance (getAdvertisementType(),
                    instantiator);
            isRegistered = true;
        }
    }

    public String [] getIndexFields() {
        return fields;
    }
}