Java String Underscore underscore(final String s, final Locale locale)

Description

Converts the given string to 'underscore' style.

License

Apache License

Parameter

Parameter	Description
s	the camel case string
locale	the Locale to use when converting to lowercase

Return

the underscored string

Declaration

public static String underscore(final String s, final Locale locale) 

Method Source Code

//package com.java2s;
/**/*from   w w w  .j  ava2s .co  m*/
 * Copyright (c) 2008-2009 Acuity Technologies, Inc.
 *
 * 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.
 *
 * Created Jan 1, 2008
 */

import java.util.ArrayList;
import java.util.Collection;

import java.util.Iterator;
import java.util.Locale;

public class Main {
    /**
     * Converts the given string to 'underscore' style. First, the string is
     * split into individual camel case words. Each word is then converted to
     * all lower case, then all the words are joined together by underscores.
     * Converts "camelCase" to "camel_case".
     *
     * @param s
     *        the camel case string
     * @return the underscored string
     */
    public static String underscore(final String s) {
        return underscore(s, Locale.getDefault());
    }

    /**
     * Converts the given string to 'underscore' style. First, the string is
     * split into individual camel case words. Each word is then converted to
     * all lower case, then all the words are joined together by underscores.
     * Converts "camelCase" to "camel_case".
     *
     * @param s
     *        the camel case string
     * @param locale
     *        the Locale to use when converting to lowercase
     * @return the underscored string
     */
    public static String underscore(final String s, final Locale locale) {
        final String[] words = splitCamelCase(s);
        for (int i = 0; i < words.length; ++i) {
            words[i] = words[i].toLowerCase(locale);
        }
        return join(words, '_');
    }

    /**
     * Splits a camel case string into individual words.
     *
     * @param s
     *        the camel case string
     * @return the individual words as a string array
     */
    public static String[] splitCamelCase(final String s) {
        final ArrayList<String> words = new ArrayList<String>();
        final int length = s.length();
        int i = 0;
        final StringBuilder sb = new StringBuilder();
        while (i < length) {
            while (i < length && Character.isUpperCase(s.charAt(i))) {
                sb.append(s.charAt(i));
                ++i;
            }
            while (i < length && !Character.isUpperCase(s.charAt(i))) {
                sb.append(s.charAt(i));
                ++i;
            }
            final String word = sb.toString();
            words.add(word);
            sb.setLength(0);
        }
        return words.toArray(new String[words.size()]);
    }

    /**
     * Join a variable argument list using commas.
     *
     * @param args
     *        the objects
     * @return The joined String
     */
    public static String join(final Object... args) {
        return join(",", args);
    }

    /**
     * Join a variable argument list of objects with the given delimiter
     * character.
     *
     * @param args
     *        the objects
     * @param c
     *        the delimiter character
     * @return The joined String
     */
    public static String join(final char c, final Object... args) {
        return join(String.valueOf(c), args);
    }

    /**
     * Join a variable argument list of objects with the given delimiter String.
     *
     * @param args
     *        the objects
     * @param delimiter
     *        the delimiter String
     * @return The joined String
     */
    public static String join(final String delimiter, final Object... args) {
        final StringBuilder sb = new StringBuilder();
        for (int i = 0; i < args.length; ++i) {
            sb.append(args[i]);
            if (i + 1 < args.length) {
                sb.append(delimiter);
            }
        }
        return sb.toString();
    }

    /**
     * Join an array of objects with the given delimiter character.
     *
     * @param <T>
     *        a type
     * @param array
     *        the String array
     * @param c
     *        the delimiter character
     * @return The joined String
     */
    public static <T> String join(final T[] array, final char c) {
        return join(array, String.valueOf(c));
    }

    /**
     * Join an array of objects with the given delimiter String.
     *
     * @param <T>
     *        a type
     * @param array
     *        the String array
     * @param delimiter
     *        the delimiter String
     * @return The joined String
     */
    public static <T> String join(final T[] array, final String delimiter) {
        final StringBuilder sb = new StringBuilder();
        for (int i = 0; i < array.length; ++i) {
            sb.append(array[i]);
            if (i + 1 < array.length) {
                sb.append(delimiter);
            }
        }
        return sb.toString();
    }

    /**
     * Joins a {@link Collection} of arbitrary objects with the given delimiter
     * character.
     *
     * @param <T>
     *        a type
     * @param collection
     *        the collection to join
     * @param c
     *        the delimiter character
     * @return The joined String
     */
    public static <T> String join(final Collection<T> collection, final char c) {
        return join(collection, String.valueOf(c));
    }

    /**
     * Joins a {@link Collection} of arbitrary objects with the given delimiter
     * String.
     *
     * @param <T>
     *        a type
     * @param collection
     *        the collection to join
     * @param delimiter
     *        the delimiter string
     * @return The joined String
     */
    public static <T> String join(final Collection<T> collection, final String delimiter) {
        final StringBuilder sb = new StringBuilder();
        for (final Iterator<T> i = collection.iterator(); i.hasNext();) {
            sb.append(i.next());
            if (i.hasNext()) {
                sb.append(delimiter);
            }
        }
        return sb.toString();
    }
}

Related

1. toUnderscored(String name)
2. toUnderscoredLowercase(String text)
3. toUnderscoreName(String name)
4. toUnderscores(String s)
5. toUnderscoreSeparated(String name)
6. underscore(String camel)
7. underscore(String camelCaseWord)
8. underscore(String field)
9. underscore(String phase)