Java String Join join(Collection items, String delimiter)

Description

Returns all items, concatenated as a string with each of the entries divided by the delimiter.

License

Open Source License

Parameter

Parameter	Description
items	Collection of items which should be joined.
delimiter	The string to insert between the <code>items</code>.

Return

A string containing all the items, separated by delimiter.

Declaration

public static String join(Collection<?> items, String delimiter) 

Method Source Code

//package com.java2s;
/**/*from w  w  w  .java  2 s .  co m*/
 * Copyright (c) 2011 - 2014 Mineground, Las Venturas Playground
 *
 * This program is free software: you can redistribute it and/or modify it under the terms of the
 * GNU General Public License as published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without
 * even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along with this program.
 * If not, see <http://www.gnu.org/licenses/>.
 */

import java.util.Arrays;
import java.util.Collection;

public class Main {
    /**
     * Returns items from <code>items</code>, concatenated as a string with each of the entries
     * divided by the <code>delimiter</code>. Only items in the range of <code>startIndex</code> to
     * <code>endIndex</code> will be included (inclusive).
     * 
     * @param items      Collection of items, some of which should be joined.
     * @param delimiter  The string to insert between the selected <code>items</code>.
     * @param startIndex The first entry in <code>items</code> to be concatenated.
     * @param endIndex   The last entry in <code>items</code> to be concatenated.
     * @return           A string containing the chosen items, separated by <code>delimiter</code>.
     */
    public static String join(Collection<?> items, String delimiter, int startIndex, int endIndex) {
        if (startIndex < 0 || startIndex > items.size() || endIndex > (items.size() - 1))
            return null; // invalid startIndex or endIndex

        StringBuilder builder = new StringBuilder();
        int currentIndex = 0;

        for (Object item : items) {
            if (currentIndex < startIndex) {
                currentIndex++;
                continue;
            }

            if (currentIndex++ > endIndex)
                break;

            builder.append(item).append(delimiter);
        }

        if (builder.length() == 0)
            return "";

        builder.setLength(builder.length() - delimiter.length());
        return builder.toString();
    }

    /**
     * Returns items from <code>items</code>, concatenated as a string with each of the entries
     * divided by the <code>delimiter</code>. Only items starting at <code>startIndex</code> will be
     * included in the joined string (inclusive).
     * 
     * @param items      Collection of items, some of which should be joined.
     * @param delimiter  The string to insert between the selected <code>items</code>.
     * @param startIndex The first entry in <code>items</code> to be concatenated.
     * @return           A string containing the chosen items, separated by <code>delimiter</code>.
     */
    public static String join(Collection<?> items, String delimiter, int startIndex) {
        return join(items, delimiter, startIndex, items.size() - 1);
    }

    /**
     * Returns all <code>items</code>, concatenated as a string with each of the entries divided
     * by the <code>delimiter</code>.
     * 
     * @param items     Collection of items which should be joined.
     * @param delimiter The string to insert between the <code>items</code>.
     * @return          A string containing all the items, separated by <code>delimiter</code>.
     */
    public static String join(Collection<?> items, String delimiter) {
        return join(items, delimiter, 0, items.size());
    }

    /**
     * Returns all <code>items</code>, concatenated as a string.
     * 
     * @param items     Collection of items which should be joined.
     * @return          A string containing all the items, separated by a space.
     */
    public static String join(Collection<?> items) {
        return join(items, " ", 0, items.size());
    }

    /**
     * Returns items from <code>items</code>, concatenated as a string with each of the entries
     * divided by the <code>delimiter</code>. Only items in the range of <code>startIndex</code> to
     * <code>endIndex</code> will be included (inclusive).
     * 
     * @param items      Collection of items, some of which should be joined.
     * @param delimiter  The string to insert between the selected <code>items</code>.
     * @param startIndex The first entry in <code>items</code> to be concatenated.
     * @param endIndex   The last entry in <code>items</code> to be concatenated.
     * @return           A string containing the chosen items, separated by <code>delimiter</code>.
     */
    public static String join(Object[] items, String delimiter, int startIndex, int endIndex) {
        return join(Arrays.asList(items), delimiter, startIndex, endIndex);
    }

    /**
     * Returns items from <code>items</code>, concatenated as a string with each of the entries
     * divided by the <code>delimiter</code>. Only items starting at <code>startIndex</code> will be
     * included in the joined string (inclusive).
     * 
     * @param items      Collection of items, some of which should be joined.
     * @param delimiter  The string to insert between the selected <code>items</code>.
     * @param startIndex The first entry in <code>items</code> to be concatenated.
     * @return           A string containing the chosen items, separated by <code>delimiter</code>.
     */
    public static String join(Object[] items, String delimiter, int startIndex) {
        return join(Arrays.asList(items), delimiter, startIndex, items.length - 1);
    }

    /**
     * Returns all <code>items</code>, concatenated as a string with each of the entries divided
     * by the <code>delimiter</code>.
     * 
     * @param items     Collection of items which should be joined.
     * @param delimiter The string to insert between the <code>items</code>.
     * @return          A string containing all the items, separated by <code>delimiter</code>.
     */
    public static String join(Object[] items, String delimiter) {
        return join(Arrays.asList(items), delimiter, 0, items.length - 1);
    }

    /**
     * Returns all <code>items</code>, concatenated as a string.
     * 
     * @param items     Collection of items which should be joined.
     * @return          A string containing all the items, separated by a space.
     */
    public static String join(Object[] items) {
        return join(Arrays.asList(items), " ", 0, items.length - 1);
    }
}

Related

1. invertPhoneNumber(String storedNumber, String joinString)
2. Join(ArrayList list, String delimiter)
3. join(boolean endSlash, Collection paths)
4. join(Collection collection, String separator)
5. join(Enumeration enumeration, String s)
6. join(Enumeration values, CharSequence separator)
7. join(final Collection input, final String link)
8. join(final String sep, final Iterable strs)