StringRepository.java

/*******************************************************************************
 * Copyright (c) 1998, 2015 Oracle and/or its affiliates. All rights reserved.
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v1.0 and Eclipse Distribution License v. 1.0
 * which accompanies this distribution.
 * The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v10.html
 * and the Eclipse Distribution License is available at
 * http://www.eclipse.org/org/documents/edl-v10.php.
 *
 * Contributors:
 *     Oracle - initial API and implementation from Oracle TopLink
******************************************************************************/
package org.eclipse.persistence.tools.workbench.framework.resources;

/**
 * This interface provides a convenient protocol for clients
 * to internationalize their messages.
 */
public interface StringRepository {

    /**
     * Return whether this repository includes the specified key.
     * Call this before calling the #getString() methods to avoid
     * excessive MissingStringExceptions being created.
     */
    boolean hasString(String key);

    /**
     * Return the localized string for the specified key.
     */
    String getString(String key);

    /**
     * Return the localized string for the specified key;
     * formatting it with the specified argument.
     */
    String getString(String key, Object argument);

    /**
     * Return the localized string for the specified key;
     * formatting it with the specified arguments.
     */
    String getString(String key, Object argument1, Object argument2);

    /**
     * Return the localized string for the specified key;
     * formatting it with the specified arguments.
     */
    String getString(String key, Object argument1, Object argument2, Object argument3);

    /**
     * Return the localized string for the specified key;
     * formatting it with the specified arguments.
     */
    String getString(String key, Object[] arguments);


    String EMPTY_STRING = "";

    /**
     * This instance will throw an exception for any non-null key
     * and return empty string for any null key.
     */
    StringRepository NULL_INSTANCE =
        new StringRepository() {
            public boolean hasString(String key) {
                return key == null;
            }
            public String getString(String key) {
                return this.getString(key, new Object[0]);
            }
            public String getString(String key, Object argument) {
                return this.getString(key, new Object[] {argument});
            }
            public String getString(String key, Object argument1, Object argument2) {
                return this.getString(key, new Object[] {argument1, argument2});
            }
            public String getString(String key, Object argument1, Object argument2, Object argument3) {
                return this.getString(key, new Object[] {argument1, argument2, argument3});
            }
            public String getString(String key, Object[] arguments) {
                if (key == null) {
                    return EMPTY_STRING;
                }
                throw new MissingStringException("Missing string: " + key, key);
            }
            public String toString() {
                return "NullStringRepository";
            }
        };

}