Java Collection Join join(Collection collection, String separator)

Description

Join an collection of objects with a separator that appears after every instance in the list -including at the end

License

Apache License

Parameter

Parameter	Description
collection	collection to call toString() on each element
separator	separator string

Return

the joined entries

Declaration

public static String join(Collection collection, String separator) 

Method Source Code

//package com.java2s;
//License from project: Apache License 

import java.util.*;

public class Main {
    /**/*w w w. ja  v  a  2 s.c o  m*/
     * Join an collection of objects with a separator that appears after every
     * instance in the list -including at the end
     *
     * @param collection collection to call toString() on each element
     * @param separator  separator string
     * @return the joined entries
     */
    public static String join(Collection collection, String separator) {
        return join(collection, separator, true);
    }

    /**
     * Join an collection of objects with a separator that appears after every
     * instance in the list -optionally at the end
     *
     * @param collection collection to call toString() on each element
     * @param separator  separator string
     * @param trailing   add a trailing entry or not
     * @return the joined entries
     */
    public static String join(Collection collection, String separator,
            boolean trailing) {
        StringBuilder b = new StringBuilder();
        // fast return on empty collection
        if (collection.isEmpty()) {
            return trailing ? separator : "";
        }
        for (Object o : collection) {
            b.append(o);
            b.append(separator);
        }
        int length = separator.length();
        String s = b.toString();
        return (trailing || s.isEmpty()) ? s : (b.substring(0, b.length()
                - length));
    }

    /**
     * Join an array of strings with a separator that appears after every
     * instance in the list -including at the end
     *
     * @param collection strings
     * @param separator  separator string
     * @return the joined entries
     */
    public static String join(String[] collection, String separator) {
        return join(collection, separator, true);

    }

    /**
     * Join an array of strings with a separator that appears after every
     * instance in the list -optionally at the end
     *
     * @param collection strings
     * @param separator  separator string
     * @param trailing   add a trailing entry or not
     * @return the joined entries
     */
    public static String join(String[] collection, String separator,
            boolean trailing) {
        return join(Arrays.asList(collection), separator, trailing);
    }
}

Related

1. join(Collection c, String left, String right, String separator)
2. join(Collection c, String separator)
3. join(Collection col, char sep)
4. join(Collection coll, String separator)
5. join(Collection collection)
6. join(Collection collection, String separator)
7. join(Collection collection, String separator)
8. join(Collection collection, String separator)
9. join(Collection collection, String separator, boolean trailing)