modelupdater.java

java xml bean把xml解析成bean

        }
        Iterator j = p.getTransitionsList().iterator();
        while (j.hasNext()) {
            updateTransition((Transition) j.next(), targets);
        }
    }

    /**
      * Update this Transition object (part of post-digestion processing).
      *
      * @param t The Transition object
      * @param targets The global Map of all transition targets
      * @throws ModelException If the object model is flawed
      */
    private static void updateTransition(final Transition t,
            final Map targets) throws ModelException {
        String next = t.getNext();
        if (next == null) { // stay transition
            return;
        }
        List tts = t.getTargets();
        if (tts.size() == 0) {
            // 'next' is a space separated list of transition target IDs
            StringTokenizer ids = new StringTokenizer(next);
            while (ids.hasMoreTokens()) {
                String id = ids.nextToken();
                TransitionTarget tt = (TransitionTarget) targets.get(id);
                if (tt == null) {
                    logAndThrowModelError(ERR_TARGET_NOT_FOUND, new Object[] {
                        id });
                }
                tts.add(tt);
            }
            if (tts.size() > 1) {
                boolean legal = verifyTransitionTargets(tts);
                if (!legal) {
                    logAndThrowModelError(ERR_ILLEGAL_TARGETS, new Object[] {
                            next });
                }
            }
        }
        t.getPaths(); // init paths
    }

    /**
      * Log an error discovered in post-digestion processing.
      *
      * @param errType The type of error
      * @param msgArgs The arguments for formatting the error message
      * @throws ModelException The model error, always thrown.
      */
    private static void logAndThrowModelError(final String errType,
            final Object[] msgArgs) throws ModelException {
        MessageFormat msgFormat = new MessageFormat(errType);
        String errMsg = msgFormat.format(msgArgs);
        org.apache.commons.logging.Log log = LogFactory.
            getLog(ModelUpdater.class);
        log.error(errMsg);
        throw new ModelException(errMsg);
    }

    /**
     * Get state identifier for error message. This method is only
     * called to produce an appropriate log message in some error
     * conditions.
     *
     * @param state The <code>State</code> object
     * @return The state identifier for the error message
     */
    private static String getStateName(final State state) {
        String badState = "anonymous state";
        if (!SCXMLHelper.isStringEmpty(state.getId())) {
            badState = "state with ID \"" + state.getId() + "\"";
        }
        return badState;
    }

    /**
     * If a transition has multiple targets, then they satisfy the following
     * criteria.
     * <ul>
     *  <li>They must belong to the regions of the same parallel</li>
     *  <li>All regions must be represented with exactly one target</li>
     * </ul>
     *
     * @param tts The transition targets
     * @return Whether this is a legal configuration
     */
    private static boolean verifyTransitionTargets(final List tts) {
        if (tts.size() <= 1) { // No contention
            return true;
        }
        TransitionTarget lca = SCXMLHelper.getLCA((TransitionTarget)
            tts.get(0), (TransitionTarget) tts.get(1));
        if (lca == null || !(lca instanceof Parallel)) {
            return false; // Must have a Parallel LCA
        }
        Parallel p = (Parallel) lca;
        Set regions = new HashSet();
        for (int i = 0; i < tts.size(); i++) {
            TransitionTarget tt = (TransitionTarget) tts.get(i);
            while (tt.getParent() != p) {
                tt = tt.getParent();
            }
            if (!regions.add(tt)) {
                return false; // One per region
            }
        }
        if (regions.size() != p.getChildren().size()) {
            return false; // Must represent all regions
        }
        return true;
    }

    /**
     * Discourage instantiation since this is a utility class.
     */
    private ModelUpdater() {
        super();
    }

    //// Error messages
    /**
     * Error message when SCXML document specifies an illegal initial state.
     */
    private static final String ERR_SCXML_NO_INIT = "No SCXML child state "
        + "with ID \"{0}\" found; illegal initialstate for SCXML document";

    /**
     * Error message when a state element specifies an initial state which
     * cannot be found.
     */
    private static final String ERR_STATE_NO_INIT = "No initial element "
        + "available for {0}";

    /**
     * Error message when a state element specifies an initial state which
     * is not a direct descendent.
     */
    private static final String ERR_STATE_BAD_INIT = "Initial state "
        + "null or not a descendant of {0}";

    /**
     * Error message when a state element contains anything other than
     * one &lt;parallel&gt;, one &lt;invoke&gt; or any number of
     * &lt;state&gt; children.
     */
    private static final String ERR_STATE_BAD_CONTENTS = "{0} should "
        + "contain either one <parallel>, one <invoke> or any number of "
        + "<state> children.";

    /**
     * Error message when a referenced history state cannot be found.
     */
    private static final String ERR_STATE_NO_HIST = "Referenced history state"
        + " null for {0}";

    /**
     * Error message when a shallow history state is not a child state.
     */
    private static final String ERR_STATE_BAD_SHALLOW_HIST = "History state"
        + " for shallow history is not child for {0}";

    /**
     * Error message when a deep history state is not a descendent state.
     */
    private static final String ERR_STATE_BAD_DEEP_HIST = "History state"
        + " for deep history is not descendant for {0}";

    /**
     * Transition target is not a legal IDREF (not found).
     */
    private static final String ERR_TARGET_NOT_FOUND =
        "Transition target with ID \"{0}\" not found";

    /**
     * Transition targets do not form a legal configuration.
     */
    private static final String ERR_ILLEGAL_TARGETS =
        "Transition targets \"{0}\" do not satisfy the requirements for"
        + " target regions belonging to a <parallel>";

    /**
     * Simple states should not contain a history.
     */
    private static final String ERR_HISTORY_SIMPLE_STATE =
        "Simple {0} contains history elements";

    /**
     * History does not specify a default transition target.
     */
    private static final String ERR_HISTORY_NO_DEFAULT =
        "No default target specified for history with ID \"{0}\""
        + " belonging to {1}";

    /**
     * History specifies a bad default transition target.
     */
    private static final String ERR_HISTORY_BAD_DEFAULT =
        "Default target specified for history with ID \"{0}\""
        + " belonging to \"{1}\" is also a history";

    /**
     * Error message when an &lt;invoke&gt; does not specify a "targettype"
     * attribute.
     */
    private static final String ERR_INVOKE_NO_TARGETTYPE = "{0} contains "
        + "<invoke> with no \"targettype\" attribute specified.";

    /**
     * Error message when an &lt;invoke&gt; does not specify a "src"
     * or a "srcexpr" attribute.
     */
    private static final String ERR_INVOKE_NO_SRC = "{0} contains "
        + "<invoke> without a \"src\" or \"srcexpr\" attribute specified.";

    /**
     * Error message when an &lt;invoke&gt; specifies both "src" and "srcexpr"
     * attributes.
     */
    private static final String ERR_INVOKE_AMBIGUOUS_SRC = "{0} contains "
        + "<invoke> with both \"src\" and \"srcexpr\" attributes specified,"
        + " must specify either one, but not both.";

}