DefaultMnemonicRepository.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;

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

import org.eclipse.persistence.tools.workbench.utility.CollectionTools;
import org.eclipse.persistence.tools.workbench.utility.string.StringTools;


/**
 * This class can be used alongside DefaultStringRepository to look up
 * strings and their mnemonics from the same JDK resource bundle.
 * The mnemonics can be indicated with an ampersand ('&') embedded
 * in the resource string. The same resource string can fetched by both
 * DefaultStringRepository and this repository. DefaultStringRepository
 * will strip off the ampersand before returning the string; while this
 * repository will use the ampersand to determine the mnemonic character
 * and index within the string.
 *
 * @see DefaultStringRepository
 */
public class DefaultMnemonicRepository implements MnemonicRepository {

    /**
     * The JDK resource bundle holding the strings that optionally have
     * mnemonics.
     */
    private ResourceBundle resourceBundle;


    // ********** constructors/initialization **********

    /**
     * Construct a mnemonic repository that for the specified
     * resource bundle.
     */
    public DefaultMnemonicRepository(String resourceClassName) {
        super();
        this.initialize(resourceClassName);
    }

    /**
     * Construct a mnemonic repository that for the specified
     * resource bundle.
     */
    public DefaultMnemonicRepository(Class resourceClass) {
        this(resourceClass.getName());
    }

    protected void initialize(String resourceClassName) {
        this.resourceBundle = ResourceBundle.getBundle(resourceClassName);
    }


    // ********** MnemonicRepository implementation **********

    /**
     * @see MnemonicRepository#hasMnemonic(String)
     */
    public boolean hasMnemonic(String key) {
        return (key == null) || CollectionTools.contains(this.resourceBundle.getKeys(), key);
    }

    /**
     * @see MnemonicRepository#getMnemonic(String)
     */
    public int getMnemonic(String key) {
        if  (key == null) {
            return -1;
        }
        String string = this.getString(key);
        int index = string.indexOf(DefaultStringRepository.MNEMONIC_CHAR);
        // return -1 if the ampersand is missing or at the very end of the string
        if ((index == -1) || (index == string.length() - 1)) {
            return -1;
        }
        // return the character immediately following the ampersand
        // it must be converted to uppercase, for some mysterious reason...
        return Character.toUpperCase(string.charAt(index + 1));
    }

    /**
     * @see MnemonicRepository#getMnemonicIndex(String)
     */
    public int getMnemonicIndex(String key) {
        return this.getString(key).indexOf(DefaultStringRepository.MNEMONIC_CHAR);
    }


    // ********** internal methods **********

    /**
     * Return the string associated with the specified key
     * by looking it up in the resource bundle.
     * Throw a MissingMnemonicException if the string is not in the
     * resource bundle.
     * Subclasses can extend this method to manipulate the string
     * returned from the resource bundle before it we look for the
     * mnemonic.
     */
    protected String getString(String key) {
        try {
            return this.resourceBundle.getString(key);
        } catch (MissingResourceException ex) {
            if (ex.getKey().equals(key)) {
                throw new MissingMnemonicException("Missing mnemonic: " + key, key);
            }
            throw ex;
        }
    }

    public String toString() {
        return StringTools.buildToStringFor(this, this.resourceBundle.getClass().getName());
    }

}