Java Iterable Join join(String separator, Iterable objects)

Description

Creates a string with toString() of each object with the given separator.

License

Apache License

Parameter

Parameter	Description
separator	The string by which to join each string representation
objects	The objects to join the string representations of

Return

The joined string

Declaration

public static String join(String separator, Iterable<?> objects) 

Method Source Code

//package com.java2s;
/*/*from   w w w. j  av a  2  s.c  o  m*/
 * Copyright 2011 the original author or authors.
 *
 * 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.
 */

import java.util.*;

public class Main {
    /**
     * Creates a string with {@code toString()} of each object with the given separator.
     *
     * <pre>
     * expect:
     * join(",", new Object[]{"a"}) == "a"
     * join(",", new Object[]{"a", "b", "c"}) == "a,b,c"
     * join(",", new Object[]{}) == ""
     * </pre>
     *
     * The {@code separator} must not be null and {@code objects} must not be null.
     *
     * @param separator The string by which to join each string representation
     * @param objects The objects to join the string representations of
     * @return The joined string
     */
    public static String join(String separator, Object[] objects) {
        return join(separator, objects == null ? null : Arrays.asList(objects));
    }

    /**
     * Creates a string with {@code toString()} of each object with the given separator.
     *
     * <pre>
     * expect:
     * join(",", ["a"]) == "a"
     * join(",", ["a", "b", "c"]) == "a,b,c"
     * join(",", []) == ""
     * </pre>
     *
     * The {@code separator} must not be null and {@code objects} must not be null.
     *
     * @param separator The string by which to join each string representation
     * @param objects The objects to join the string representations of
     * @return The joined string
     */
    public static String join(String separator, Iterable<?> objects) {
        if (separator == null) {
            throw new NullPointerException("The 'separator' cannot be null");
        }
        if (objects == null) {
            throw new NullPointerException("The 'objects' cannot be null");
        }

        StringBuilder string = new StringBuilder();
        Iterator<?> iterator = objects.iterator();
        if (iterator.hasNext()) {
            string.append(iterator.next().toString());
            while (iterator.hasNext()) {
                string.append(separator);
                string.append(iterator.next().toString());
            }
        }
        return string.toString();
    }
}

Related

1. join(String delimiter, String wrap, Iterable objs)
2. join(String glue, Iterable pieces)
3. join(String glue, Iterable tokens)
4. join(String sep, Iterable strings)
5. join(String separator, Iterable elements)
6. join(String separator, Iterable args)
7. join(String seperator, Iterator objects)
8. join(String seprator, Iterable coll)
9. join(StringBuilder buf, Iterable values, String separator)