propertymessageresources.java

structs源码

        }

        // Initialize variables we will require
        String localeKey = localeKey(locale);
        String originalKey = messageKey(localeKey, key);
        String message = null;

        // Search the specified Locale
        message = findMessage(locale, key, originalKey);
        if (message != null) {
            return message;
        }

        // JSTL Compatibility - JSTL doesn't use the default locale
        if (mode == MODE_JSTL) {

           // do nothing (i.e. don't use default Locale)

        // PropertyResourcesBundle - searches through the hierarchy
        // for the default Locale (e.g. first en_US then en)
        } else if (mode == MODE_RESOURCE_BUNDLE) {

            if (!defaultLocale.equals(locale)) {
                message = findMessage(defaultLocale, key, originalKey);
            }

        // Default (backwards) Compatibility - just searches the
        // specified Locale (e.g. just en_US)
        } else {

            if (!defaultLocale.equals(locale)) {
                localeKey = localeKey(defaultLocale);
                message = findMessage(localeKey, key, originalKey);
            }

        }
        if (message != null) {
            return message;
        }

        // Find the message in the default properties file
        message = findMessage("", key, originalKey);
        if (message != null) {
            return message;
        }

        // Return an appropriate error indication
        if (returnNull) {
            return (null);
        } else {
            return ("???" + messageKey(locale, key) + "???");
        }
    }

    // ------------------------------------------------------ Protected Methods

    /**
     * Load the messages associated with the specified Locale key.  For this
     * implementation, the <code>config</code> property should contain a fully
     * qualified package and resource name, separated by periods, of a series
     * of property resources to be loaded from the class loader that created
     * this PropertyMessageResources instance.  This is exactly the same name
     * format you would use when utilizing the <code>java.util.PropertyResourceBundle</code>
     * class.
     *
     * @param localeKey Locale key for the messages to be retrieved
     */
    protected synchronized void loadLocale(String localeKey) {
        if (log.isTraceEnabled()) {
            log.trace("loadLocale(" + localeKey + ")");
        }

        // Have we already attempted to load messages for this locale?
        if (locales.get(localeKey) != null) {
            return;
        }

        locales.put(localeKey, localeKey);

        // Set up to load the property resource for this locale key, if we can
        String name = config.replace('.', '/');

        if (localeKey.length() > 0) {
            name += ("_" + localeKey);
        }

        name += ".properties";

        InputStream is = null;
        Properties props = new Properties();

        // Load the specified property resource
        if (log.isTraceEnabled()) {
            log.trace("  Loading resource '" + name + "'");
        }

        ClassLoader classLoader =
            Thread.currentThread().getContextClassLoader();

        if (classLoader == null) {
            classLoader = this.getClass().getClassLoader();
        }

        is = classLoader.getResourceAsStream(name);

        if (is != null) {
            try {
                props.load(is);
            } catch (IOException e) {
                log.error("loadLocale()", e);
            } finally {
                try {
                    is.close();
                } catch (IOException e) {
                    log.error("loadLocale()", e);
                }
            }
            if (log.isTraceEnabled()) {
                log.trace("  Loading resource completed");
            }
        } else {
            if (log.isWarnEnabled()) {
                log.warn("  Resource "+name+" Not Found.");
            }
        }


        // Copy the corresponding values into our cache
        if (props.size() < 1) {
            return;
        }

        synchronized (messages) {
            Iterator names = props.keySet().iterator();

            while (names.hasNext()) {
                String key = (String) names.next();

                if (log.isTraceEnabled()) {
                    log.trace("  Saving message key '"
                        + messageKey(localeKey, key));
                }

                messages.put(messageKey(localeKey, key), props.getProperty(key));
            }
        }
    }

    // -------------------------------------------------------- Private Methods

    /**
     * Returns a text message for the specified key, for the specified Locale.
     * <p>
     * A null string result will be returned by this method if no relevant
     * message resource is found. This method searches through the locale
     * <i>hierarchy</i> (i.e. variant --> languge --> country) for the message.
     *
     * @param locale The requested message Locale, or <code>null</code> for
     *  the system default Locale
     * @param key The message key to look up
     * @param originalKey The original message key to cache any found message under
     * @return text message for the specified key and locale
     */
    private String findMessage(Locale locale, String key, String originalKey) {

        // Initialize variables we will require
        String localeKey = localeKey(locale);
        String messageKey = null;
        String message = null;
        int underscore = 0;

        // Loop from specific to general Locales looking for this message
        while (true) {
            message = findMessage(localeKey, key, originalKey);
            if (message != null) {
                break;
            }

            // Strip trailing modifiers to try a more general locale key
            underscore = localeKey.lastIndexOf("_");

            if (underscore < 0) {
                break;
            }

            localeKey = localeKey.substring(0, underscore);
        }

        return message;

    }

    /**
     * Returns a text message for the specified key, for the specified Locale.
     * <p>
     * A null string result will be returned by this method if no relevant
     * message resource is found.
     *
     * @param locale The requested key of the Locale
     * @param key The message key to look up
     * @param originalKey The original message key to cache any found message under
     * @return text message for the specified key and locale
     */
    private String findMessage(String localeKey, String key, String originalKey) {

        // Load this Locale's messages if we have not done so yet
        loadLocale(localeKey);

        // Check if we have this key for the current locale key
        String messageKey = messageKey(localeKey, key);

        // Add if not found under the original key
        boolean addIt = !messageKey.equals(originalKey);

        synchronized (messages) {
            String message = (String) messages.get(messageKey);

            if (message != null) {
                if (addIt) {
                    messages.put(originalKey, message);
                }

            }
            return (message);
        }
    }
}