requestctx.java

来自「sunxacml源码」· Java 代码 · 共 475 行 · 第 1/2 页

                    node.getAttributes().getNamedItem("SubjectCategory");
                URI category = null;

                if (catNode != null) {
                    try {
                        category = new URI(catNode.getNodeValue());
                    } catch (Exception e) {
                        throw new ParsingException("Invalid Category URI", e);
                    }
                }
                
                // now we get the attributes
                Set attributes = parseAttributes(node);

                // finally, add the list to the set of subject attributes
                newSubjects.add(new Subject(category, attributes));
            } else if (tag.equals("Resource")) {
                // For now, this code doesn't parse the content, since it's
                // a set of anys with a set of anyAttributes, and therefore
                // no useful data can be gleaned from it anyway. The theory
                // here is that it's only useful in the instance doc, so
                // we won't bother parse it, but we may still want to go
                // back and provide some support at some point...
                newResource = parseAttributes(node);
            } else if (tag.equals("Action")) {
                newAction = parseAttributes(node);
            } else if (tag.equals("Environment")) {
                newEnvironment = parseAttributes(node);
            }
        }

        // if we didn't have an environment section, the only optional section
        // of the four, then create a new empty set for it
        if (newEnvironment == null)
            newEnvironment = new HashSet();

        // Now create and return the RequestCtx from the information
        // gathered
        return new RequestCtx(newSubjects, newResource,
                              newAction, newEnvironment, root);
    }

    /* 
     * Helper method that parses a set of Attribute types. The Subject,
     * Action and Environment sections all look like this.
     */
    private static Set parseAttributes(Node root) throws ParsingException {
        Set set = new HashSet();

        // the Environment section is just a list of Attributes
        NodeList nodes = root.getChildNodes();
        for (int i = 0; i < nodes.getLength(); i++) {
            Node node = nodes.item(i);
            if (node.getNodeName().equals("Attribute"))
                set.add(Attribute.getInstance(node));
        }

        return set;
    }

    /**
     * Creates a new <code>RequestCtx</code> by parsing XML from an
     * input stream. Note that this a convenience method, and it will
     * not do schema validation by default. You should be parsing the data
     * yourself, and then providing the root node to the other
     * <code>getInstance</code> method. If you use this convenience
     * method, you probably want to turn on validation by setting the
     * context schema file (see the programmer guide for more information
     * on this).
     *
     * @param input a stream providing the XML data
     *
     * @return a new <code>RequestCtx</code>
     *
     * @throws ParserException if there is an error parsing the input
     */
    public static RequestCtx getInstance(InputStream input)
        throws ParsingException
    {
        return getInstance(InputParser.parseInput(input, "Request"));
    }

    /**
     * Returns a <code>Set</code> containing <code>Subject</code> objects.
     *
     * @return the request's subject attributes
     */
    public Set getSubjects() {
        return subjects;
    }

    /**
     * Returns a <code>Set</code> containing <code>Attribute</code> objects.
     *
     * @return the request's resource attributes
     */
    public Set getResource() {
        return resource;
    }

    /**
     * Returns a <code>Set</code> containing <code>Attribute</code> objects.
     *
     * @return the request's action attributes
     */
    public Set getAction() {
        return action;
    }

    /**
     * Returns a <code>Set</code> containing <code>Attribute</code> objects.
     *
     * @return the request's environment attributes
     */
    public Set getEnvironmentAttributes() {
        return environment;
    }

    /**
     * Returns the root DOM node of the document used to create this
     * object, or null if this object was created by hand (ie, not through
     * the <code>getInstance</code> method) or if the root node was not
     * provided to the constructor.
     *
     * @return the root DOM node or null
     */
    public Node getDocumentRoot() {
        return documentRoot;
    }

    /**
     * Encodes this context into its XML representation and writes this
     * encoding to the given <code>OutputStream</code>.  No
     * indentation is used.
     *
     * @param output a stream into which the XML-encoded data is written
     */
    public void encode(OutputStream output) {
        encode(output, new Indenter(0));
    }

    /**
     * Encodes this context into its XML representation and writes
     * this encoding to the given <code>OutputStream</code> with
     * indentation.
     *
     * @param output a stream into which the XML-encoded data is written
     * @param indenter an object that creates indentation strings
     */
    public void encode(OutputStream output, Indenter indenter) {

        // Make a PrintStream for a nicer printing interface
        PrintStream out = new PrintStream(output);

        // Prepare the indentation string
        String topIndent = indenter.makeString();
        out.println(topIndent + "<Request>");

        // go in one more for next-level elements...
        indenter.in();
        String indent = indenter.makeString();

        // ...and go in again for everything else
        indenter.in();

        // first off, go through all subjects
        Iterator it = subjects.iterator();
        while (it.hasNext()) {
            Subject subject = (Subject)(it.next());

            out.print(indent + "<Subject SubjectCategory=\"" +
                      subject.getCategory().toString() + "\"");

            Set subjectAttrs = subject.getAttributes();
            
            if (subjectAttrs.size() == 0) {
                // there's nothing in this Subject, so just close the tag
                out.println("/>");
            } else {
                // there's content, so fill it in
                out.println(">");

                encodeAttributes(subjectAttrs, out, indenter);
            
                out.println(indent + "</Subject>");
            }
        }

        // next do the resource
        if ((resource.size() != 0) || (resourceContent != null)) {
            out.println(indent + "<Resource>");
            if (resourceContent != null)
                out.println(indenter.makeString() + "<ResourceContent>" +
                            resourceContent + "</ResourceContent>");
            encodeAttributes(resource, out, indenter);
            out.println(indent + "</Resource>");
        } else {
            out.println(indent + "<Resource/>");
        }

        // now the action
        if (action.size() != 0) {
            out.println(indent + "<Action>");
            encodeAttributes(action, out, indenter);
            out.println(indent + "</Action>");
        } else {
            out.println(indent + "<Action/>");
        }

        // finally the environment, if there are any attrs
        if (environment.size() != 0) {
            out.println(indent + "<Environment>");
            encodeAttributes(environment, out, indenter);
            out.println(indent + "</Environment>");
        }

        // we're back to the top
        indenter.out();
        indenter.out();
        
        out.println(topIndent + "</Request>");
    }

    /**
     * Private helper function to encode the attribute sets
     */
    private void encodeAttributes(Set attributes, PrintStream out,
                                  Indenter indenter) {
        Iterator it = attributes.iterator();
        while (it.hasNext()) {
            Attribute attr = (Attribute)(it.next());
            attr.encode(out, indenter);
        }
    }

}