DefaultLocalizationBundleFactory.java

/* Copyright 2005-2006 Tim Fennell
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package net.sourceforge.stripes.localization;

import net.sourceforge.stripes.config.Configuration;

import java.util.ResourceBundle;
import java.util.Locale;
import java.util.MissingResourceException;

/**
 * Very simple default implementation of a bundle factory.  Looks for configuration parameters in
 * the bootstrap properties called "LocalizationBundleFactory.ErrorMessageBundle" and
 * "LocalizationBundleFactory.FieldNameBundle".  If one or both of these values is not specified
 * the default bundle name of "StripesResources" will be used in its place.
 *
 * @see net.sourceforge.stripes.config.BootstrapPropertyResolver
 * @author Tim Fennell
 */
public class DefaultLocalizationBundleFactory implements LocalizationBundleFactory {

    /** The name of the default resource bundle for Stripes. */
    public static final String BUNDLE_NAME = "StripesResources";

    /** The configuration parameter for changing the default error message resource bundle. */
    public static final String ERROR_MESSAGE_BUNDLE = "LocalizationBundleFactory.ErrorMessageBundle";

    /** The configuration parameter for changing the default field name resource bundle. */
    public static final String FIELD_NAME_BUNDLE = "LocalizationBundleFactory.FieldNameBundle";

    /** Holds the configuration passed in at initialization time. */
    private Configuration configuration;
    private String errorBundleName;
    private String fieldBundleName;

    /**
     * Uses the BootstrapPropertyResolver attached to the Configuration in order to look for
     * configured bundle names in the servlet init parameters etc.  If those can't be found then
     * the default bundle names are put in place.
     */
    public void init(Configuration configuration) throws Exception {
        setConfiguration(configuration);

        this.errorBundleName = configuration.getBootstrapPropertyResolver().
                getProperty(ERROR_MESSAGE_BUNDLE);
        if (this.errorBundleName == null) {
            this.errorBundleName = BUNDLE_NAME;
        }

        this.fieldBundleName = configuration.getBootstrapPropertyResolver().
                getProperty(FIELD_NAME_BUNDLE);
        if (this.fieldBundleName == null) {
            this.fieldBundleName = BUNDLE_NAME;
        }
    }

    /**
     * Looks for a bundle called StripesResources with the supplied locale if one is provided,
     * or with the default locale if the locale provided is null.
     *
     * @param locale an optional locale, may be null.
     * @return ResourceBundle a bundle in which to look for localized error messages
     * @throws MissingResourceException if a suitable bundle cannot be found
     */
    public ResourceBundle getErrorMessageBundle(Locale locale) throws MissingResourceException {
        try {
            if (locale == null) {
                return ResourceBundle.getBundle(this.errorBundleName);
            }
            else {
                return ResourceBundle.getBundle(this.errorBundleName, locale);
            }
        }
        catch (MissingResourceException mre) {
            MissingResourceException mre2 = new MissingResourceException(
                    "Could not find the error message resource bundle needed by Stripes. This " +
                    "almost certainly means that a properties file called '" +
                    this.errorBundleName + ".properties' could not be found in the classpath. " +
                    "This properties file is needed to lookup validation error messages. Please " +
                    "ensure the file exists in WEB-INF/classes or elsewhere in your classpath.",
                    this.errorBundleName, "");
            mre2.setStackTrace(mre.getStackTrace());
            throw mre2;
        }
    }

    /**
     * Looks for a bundle called StripesResources with the supplied locale if one is provided,
     * or with the default locale if the locale provided is null.
     *
     * @param locale an optional locale, may be null.
     * @return ResourceBundle a bundle in which to look for localized field names
     * @throws MissingResourceException if a suitable bundle cannot be found
     */
    public ResourceBundle getFormFieldBundle(Locale locale) throws MissingResourceException {
        try {
            if (locale == null) {
                return ResourceBundle.getBundle(this.fieldBundleName);
            }
            else {
                return ResourceBundle.getBundle(this.fieldBundleName, locale);
            }
        }
        catch (MissingResourceException mre) {
            MissingResourceException mre2 = new MissingResourceException(
                    "Could not find the form field resource bundle needed by Stripes. This " +
                    "almost certainly means that a properties file called '" +
                    this.fieldBundleName + ".properties' could not be found in the classpath. " +
                    "This properties file is needed to lookup form field names. Please " +
                    "ensure the file exists in WEB-INF/classes or elsewhere in your classpath.",
                    this.fieldBundleName, "");
            mre2.setStackTrace(mre.getStackTrace());
            throw mre2;
        }
    }

	protected Configuration getConfiguration()
	{
		return configuration;
	}

	protected void setConfiguration(Configuration configuration)
	{
		this.configuration = configuration;
	}
}