Java Collection to String collectionToString(Collection collection)

Description

Returns a collection of Strings as a comma-delimitted list of strings.

License

Open Source License

Return

a String representing the Collection.

Declaration

public static String collectionToString(Collection<String> collection) 

Method Source Code

//package com.java2s;
/**/*from  ww  w.java 2 s . c  o  m*/
 * Check whether the given String has actual text. More specifically,
 * returns <code>true</code> if the string not <code>null</code>, its length
 * is greater than 0, and it contains at least one non-whitespace character.
 * <p/>
 * <code>StringUtils.hasText(null) == false<br/>
 * StringUtils.hasText("") == false<br/>
 * StringUtils.hasText(" ") == false<br/>
 * StringUtils.hasText("12345") == true<br/>
 * StringUtils.hasText(" 12345 ") == true</code>
 * <p/>
 * <p>
 * Copied from the Spring Framework while retaining all license, copyright
 * and author information.
 *
 * @param str the String to check (may be <code>null</code>)
 * @return <code>true</code> if the String is not <code>null</code>, its
 * length is greater than 0, and it does not contain whitespace only
 * @see Character#isWhitespace
 */

import java.util.Collection;

public class Main {
    /**
     * Constant representing the empty string, equal to &quot;&quot;
     */
    public static final String EMPTY_STRING = "";

    /**
     * Returns a collection of Strings as a comma-delimitted list of strings.
     *
     * @return a String representing the Collection.
     */
    public static String collectionToString(Collection<String> collection) {
        if (collection == null || collection.isEmpty()) {
            return "";
        }
        StringBuilder buf = new StringBuilder();
        String delim = "";
        for (String element : collection) {
            buf.append(delim);
            buf.append(element);
            delim = ",";
        }
        return buf.toString();
    }

    public static boolean isEmpty(String s) {
        return isBlank(s);
    }

    /**
     * Returns the specified array as a comma-delimited (',') string.
     *
     * @param array the array whose contents will be converted to a string.
     * @return the array's contents as a comma-delimited (',') string.
     * @since 1.0
     */
    public static String toString(Object[] array) {
        return toDelimitedString(array, ",");
    }

    public static boolean isBlank(String s) {
        if (s == null) {
            return true;
        }
        if (s.trim().length() == 0) {
            return true;
        }
        return false;
    }

    /**
     * Returns the array's contents as a string, with each element delimited by
     * the specified {@code delimiter} argument. Useful for {@code toString()}
     * implementations and log messages.
     *
     * @param array the array whose contents will be converted to a string
     * @param delimiter the delimiter to use between each element
     * @return a single string, delimited by the specified {@code delimiter}.
     * @since 1.0
     */
    public static String toDelimitedString(Object[] array, String delimiter) {
        if (array == null || array.length == 0) {
            return EMPTY_STRING;
        }
        StringBuilder sb = new StringBuilder();
        for (int i = 0; i < array.length; i++) {
            if (i > 0) {
                sb.append(delimiter);
            }
            sb.append(array[i]);
        }
        return sb.toString();
    }
}

Related

1. collectionToString(Collection elements)
2. collectionToString(Collection list)
3. collectionToString(Collection list)
4. collectionToString(Collection collection, String prefix)
5. collectionToString(Collection