resource.java

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

        List values = getAll(key, (d != null) ? d.toString() : null);

        return Conversion.toClasses(values);
    }

    /**
     * Specifies a named resource to the null value.
     *
     * @param       key     specified resource name
     */
    
    public void set(String key) {
        set(key, null);
    }

    /**
     * Specifies a named resource to the provided value.
     *
     * @param       key     specified resource name
     * @param       value   specified resource value
     */
    
    public void set(String key, String value) {
        synchronized (this.root) {
            String k = key;
            Object o = getValue(k);
            
            if ((o = getValue(k)) == null) {
                String l = k;
                int i = 0;

                while ((o = getValue(l)) == null &&
                    i > -1) {
                    i = l.lastIndexOf(ELEMENT_DELIMITER);
                    l = l.substring(0, i);
                }

                if (o == null) {
                    o = this.root;
                }
                
                int j = 0;

                while (j > -1) {
                    j = k.indexOf(ELEMENT_DELIMITER, i + ELEMENT_DELIMITER.length());
                    
                    String m = j > -1 ?
                        k.substring(i + ELEMENT_DELIMITER.length(), i) :
                        k.substring(i + ELEMENT_DELIMITER.length());
                    
                    if (m.startsWith(ATTRIBUTE_DELIMITER)) {
                        ((Element)o).setAttribute(m.substring(ATTRIBUTE_DELIMITER.length()), "");
                    } else {
                        ((Element)o).appendChild(((Element)o).getOwnerDocument().createElement(m));
                    }
                    
                    o = getValue(j > -1 ? k.substring(0, j) + m : k);

                    if (j > -1) {
                        i = j;
                    }
                }
            }

            if (o != null) {
                if (o instanceof Attr) {
                    Attr a = (Attr)o;
                    Element p = a.getOwnerElement();

                    if (value != null) {
                        try {
                            p.setAttribute(a.getName(), value);
                        } catch (DOMException de) {
                        }
                    } else {
                        try {
                            p.removeAttribute(a.getName());
                        } catch (DOMException de) {
                        }
                    }
                } else if (o instanceof Element) {
                    Element e = (Element)o;

                    if (value != null) {
                        try {
                            e.setTextContent(value);
                        } catch (DOMException de) {
                        }
                    } else {
                        try {
                            e.getParentNode().removeChild(e);
                        } catch (DOMException de) {
                        }
                    }
                }
            }
        }
    }

    /**
     * Accessor to a named resource.
     *
     * @param       key     specified resource name
     * @return              resource value as a {@link java.util.List}
     */
    
    public List getAll(String key) {
        return getAll(key, null);
    }
    
    /**
     * Accessor to a named resource.
     *
     * @param       key     specified resource name
     * @param       d       specified default value
     * @return              resource value as a {@link java.util.List} or the
     *                      specified default value if the named resource value
     *                      is not resolvible.
     */

    public List getAll(String key, String d) {
        return getValues(key, d);
    }

    /**
     * Resource containment validator. 
     *
     * @param       key     specified resource name
     * @return              containment test results
     */
    
    public boolean contains(String key) {
        return get(key) != null;
    }

    /**
     * Accessor to the {@link java.lang.String} representation of this instance.
     *
     * @return              {@link java.lang.String} representation of this instance
     */
    
    public String toString() {
        StringBuffer sb = new StringBuffer();

        if (this.root.hasChildNodes()) {
            Node n = this.root.getFirstChild();

            while (n != null) {
                if (n instanceof Element) {
                    if (sb.length() > 0) {
                        sb.append(NEW_LINE);
            }

                    sb.append(toString((Element)n));
        }

                n = n.getNextSibling();
            }
    }

        return sb.toString();
    }
     
    private void process(Object resource)
    throws ResourceNotFoundException {
        process(resource, null);
    }

    private void process(Object resource, Class clazz)
    throws ResourceNotFoundException {
        if (!this.resources.contains(resource)) {
            Element el = null;
            Exception ex = null;

            if (resource instanceof URL) {
                try {
                    el = getRootElement((URL)resource);
                } catch (SAXException se) {
                    ex = se;
                } catch (IOException ioe) {
                    ex = ioe;
                }
            } else if (resource instanceof String) {
                if (clazz == null) {
                    clazz = Resource.class;
                }

                try {
                    el = getRootElement(clazz.getResourceAsStream((String)resource));
                } catch (SAXException se) {
                    ex = se;
                } catch (IOException ioe) {
                    ex = ioe;
                }
            } else if (resource instanceof InputStream) {
                try {
                    el = getRootElement((InputStream)resource);
                } catch (SAXException se) {
                    ex = se;
                } catch (IOException ioe) {
                    ex = ioe;
                }

                resource = new String("InputStream." + System.currentTimeMillis());
            }

            if (el != null &&
                ex == null) {
                load(resource, el);
            } else {
                throw new ResourceNotFoundException(EXCEPTION_PREFIX + ": " +
                                                    resource.toString(), ex);
            }
        }
    }

    private Element getRootElement(URL resource)
    throws SAXException, IOException {
        return getRootElement(resource.openStream());
    }

    private Element getRootElement(InputStream is)
    throws SAXException, IOException {
        return getDocumentBuilder().parse(is).getDocumentElement();
    }

    private synchronized DocumentBuilder getDocumentBuilder() {
        if (this.db == null) {
            try {
                this.db = DocumentBuilderFactory.newInstance().newDocumentBuilder();
            } catch (ParserConfigurationException pce) {
            }
        }

        return this.db;
    }

    private void load(Object resource, Element element) {
        if (resources != null &&
            element != null) {
            synchronized (lock) {
                Document d = this.root.getOwnerDocument();
                boolean isValid = false;
                
                try {
                    this.root.appendChild(d.importNode(element, true));
                    
                    isValid = true;
                } catch (DOMException de) {
                }
                
                if (isValid) {
                this.resources.add(resource);
                }
            }
        }
    }

    private String getValue(String key, String d) {
        String v = null;
        Object o = getValue(key);

        if (o != null) {
            if (o instanceof Attr) {
                v = ((Attr)o).getValue();
            } else if (o instanceof Element) {
                v = textToString((Element)o);
            }
        }
        
        return Util.expand(v != null ? v : d);
    }

    private Object getValue(String key) {
        Object o = null;

        // xxx: key munging, may not work with non-default root elements
        key = DOT + key;
        
            try {
            o = getXPath().evaluate(key, this.root, XPathConstants.NODE);
        } catch (XPathExpressionException xpee) {
        }

        return o;
    }

    private List getValues(String key, String d) {
        List v = new ArrayList();
        Object o = null;

        for (Iterator vi = getValues(key).iterator(); vi.hasNext(); ) {
            o = vi.next();

            if (o != null) {
		String nv = null;

                if (o instanceof Attr) {
		    nv = ((Attr)o).getValue();
                } else if (o instanceof Element) {
                    Node n = ((Element)o).getFirstChild();

		    if (n != null) {
                        try {
			    nv = n.getNodeValue();
                        } catch (DOMException de) {
			}
                    }
                }

		if (nv != null) {
		    v.add(Util.expand(nv));
		}
            }
        }

        if (v.size() == 0 &&
            d != null) {
            v.add(Util.expand(d));
        }

        return v;
    }

    private List getValues(String key) {
        List v = new ArrayList();
        NodeList nl = null;

        // xxx: key munging, may not work with non-default root elements
        key = DOT + key;

            try {
            nl = (NodeList)getXPath().evaluate(key, this.root, XPathConstants.NODESET);
        } catch (XPathExpressionException xee) {
        }

        for (int i = 0; nl != null && i < nl.getLength(); i++) {
            v.add((Node)nl.item(i));
    }

        return v;
        }

    private synchronized XPath getXPath() {
        return (this.xp != null ?
            this.xp : (this.xp = XPathFactory.newInstance().newXPath()));
    }

    private Document getRootDocument() {
        return getRootDocument(true);
    }

    private Document getRootDocument(boolean isClone) {
        Document d = null;

        if (isClone) {
            d = getDocumentBuilder().newDocument();
            
            try {
                d.appendChild(this.root.cloneNode(true));
            } catch (DOMException de) {
            }
        } else if ((d = this.root.getOwnerDocument()) == null) {
            d = getDocumentBuilder().newDocument();
            
            try {
                d.appendChild(this.root);
            } catch (DOMException de) {
            }
        }

        return d;
    }
  
    private String toString(Element e) {
        String s = null;
        Transformer t = null;
        
        try {
            t = TransformerFactory.newInstance().newTransformer();
        } catch (TransformerFactoryConfigurationError tfce) {
        } catch (TransformerConfigurationException tce) {
        }
        
        if (t != null) {
            StringWriter w = new StringWriter();
            
            try {
                t.transform(new DOMSource(e), new StreamResult(w));
            } catch (TransformerException te) {
            }
            
            s = w.toString();
        }
        
        return s;
    }
    
    private String textToString(Element e) {
        StringBuffer sb = new StringBuffer();
        NodeList cnl = e.getChildNodes();
                
        for (int i = 0; i < cnl.getLength(); i++) {
            Node cn = (Node)cnl.item(i);
            
            if (cn.getNodeType() == Node.TEXT_NODE ||
                cn.getNodeType() == Node.CDATA_SECTION_NODE) {
                sb.append(cn.getTextContent().trim());
            }
        }
        
        return sb.toString().trim();
    }
}