JavaNameGenerator

package org.apache.torque.engine.database.model;

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.
 */

import java.util.List;
import java.util.StringTokenizer;

import org.apache.commons.lang.StringUtils;

/**
 * A <code>NameGenerator</code> implementation for Java-esque names.
 *
 * @author <a href="mailto:dlr@finemaltcoding.com>Daniel Rall</a>
 * @author <a href="mailto:byron_foster@byron_foster@yahoo.com>Byron Foster</a>
 * @version $Id: JavaNameGenerator.java,v 1.1 2007-10-21 07:57:27 abyrne Exp $
 */
public class JavaNameGenerator implements NameGenerator
{
    /**
     * <code>inputs</code> should consist of two elements, the
     * original name of the database element and the method for
     * generating the name.  There are currently three methods:
     * <code>CONV_METHOD_NOCHANGE</code> - xml names are converted
     * directly to java names without modification.
     * <code>CONV_METHOD_UNDERSCORE</code> will capitalize the first
     * letter, remove underscores, and capitalize each letter before
     * an underscore.  All other letters are lowercased. "javaname"
     * works the same as the <code>CONV_METHOD_JAVANAME</code> method
     * but will not lowercase any characters.
     *
     * @param inputs list expected to contain two parameters, element
     * 0 contains name to convert, element 1 contains method for conversion.
     * @return The generated name.
     * @see org.apache.torque.engine.database.model.NameGenerator
     */
    public String generateName(List inputs)
    {
        String schemaName = (String) inputs.get(0);
        String method = (String) inputs.get(1);
        String javaName = null;

        if (CONV_METHOD_UNDERSCORE.equals(method))
        {
            javaName = underscoreMethod(schemaName);
        }
        else if (CONV_METHOD_UNDERSCORE_OMIT_SCHEMA.equals(method))
        {
            javaName = underscoreOmitSchemaMethod(schemaName);
        }
        else if (CONV_METHOD_JAVANAME.equals(method))
        {
            javaName = javanameMethod(schemaName);
        }
        else if (CONV_METHOD_NOCHANGE.equals(method))
        {
            javaName = nochangeMethod(schemaName);
        }
        else
        {
            // if for some reason nothing is defined then we default
            // to the traditional method.
            javaName = underscoreMethod(schemaName);
        }

        return javaName;
    }

    /**
     * Converts a database schema name to java object name.  Removes
     * <code>STD_SEPARATOR_CHAR</code> and <code>SCHEMA_SEPARATOR_CHAR</code>,
     * capitilizes first letter of name and each letter after the
     * <code>STD_SEPERATOR</code> and <code>SCHEMA_SEPARATOR_CHAR</code>,
     * converts the rest of the letters to lowercase.
     *
     * @param schemaName name to be converted.
     * @return converted name.
     * @see org.apache.torque.engine.database.model.NameGenerator
     * @see #underscoreMethod(String)
     */
    protected String underscoreMethod(String schemaName)
    {
        StringBuffer name = new StringBuffer();

        // remove the STD_SEPARATOR_CHARs and capitalize
        // the tokens
        StringTokenizer tok = new StringTokenizer
            (schemaName, String.valueOf(STD_SEPARATOR_CHAR));
        while (tok.hasMoreTokens())
        {
            String namePart = ((String) tok.nextElement()).toLowerCase();
            name.append(StringUtils.capitalize(namePart));
        }

        // remove the SCHEMA_SEPARATOR_CHARs and capitalize
        // the tokens
        schemaName = name.toString();
        name = new StringBuffer();
        tok = new StringTokenizer
            (schemaName, String.valueOf(SCHEMA_SEPARATOR_CHAR));
        while (tok.hasMoreTokens())
        {
            String namePart = (String) tok.nextElement();
            name.append(StringUtils.capitalize(namePart));
        }
        return name.toString();
    }

    /**
     * Converts a database schema name to java object name.
     * First, it removes all characters before the last occurence of
     * .<code>SCHEMA_SEPARATOR_CHAR</code>. Then, in a second step, removes
     * <code>STD_SEPARATOR_CHAR</code>, capitilizes first letter of
     * name and each letter after the <code>STD_SEPERATOR</code>,
     * and converts the rest of the letters to lowercase.
     *
     * @param schemaName name to be converted.
     * @return converted name.
     * @see org.apache.torque.engine.database.model.NameGenerator
     * @see #underscoreOmitSchemaMethod(String)
     */
    protected String underscoreOmitSchemaMethod(String schemaName)
    {
        // take only part after last dot
        int lastDotPos = schemaName.lastIndexOf(SCHEMA_SEPARATOR_CHAR);
        if (lastDotPos != -1)
        {
            schemaName = schemaName.substring(lastDotPos + 1);
        }
        StringBuffer name = new StringBuffer();
        StringTokenizer tok = new StringTokenizer
            (schemaName, String.valueOf(STD_SEPARATOR_CHAR));
        while (tok.hasMoreTokens())
        {
            String namePart = ((String) tok.nextElement()).toLowerCase();
            name.append(StringUtils.capitalize(namePart));
        }
        return name.toString();
    }

    /**
     * Converts a database schema name to java object name.  Operates
     * same as underscoreMethod but does not convert anything to
     * lowercase.
     *
     * @param schemaName name to be converted.
     * @return converted name.
     * @see org.apache.torque.engine.database.model.NameGenerator
     * @see #underscoreMethod(String)
     */
    protected String javanameMethod(String schemaName)
    {
        StringBuffer name = new StringBuffer();
        StringTokenizer tok = new StringTokenizer
            (schemaName, String.valueOf(STD_SEPARATOR_CHAR));
        while (tok.hasMoreTokens())
        {
            String namePart = (String) tok.nextElement();
            name.append(StringUtils.capitalize(namePart));
        }

        // remove the SCHEMA_SEPARATOR_CHARs and capitalize
        // the tokens
        schemaName = name.toString();
        name = new StringBuffer();

        tok = new StringTokenizer
            (schemaName, String.valueOf(SCHEMA_SEPARATOR_CHAR));
        while (tok.hasMoreTokens())
        {
            String namePart = (String) tok.nextElement();
            name.append(StringUtils.capitalize(namePart));
        }
        return name.toString();
    }

    /**
     * Converts a database schema name to java object name.  In this
     * case no conversion is made.
     *
     * @param name name to be converted.
     * @return The <code>name</code> parameter, unchanged.
     */
    protected final String nochangeMethod(String name)
    {
        return name;
    }
}