Java Collection Element Get getCommaDelimitedString(Collection elements)

Description

Transforms a collection of Integers into a comma delimited String.

License

Open Source License

Parameter

Parameter	Description
elements	the collection of Integers

Return

a comma delimited String.

Declaration

public static String getCommaDelimitedString(Collection<?> elements) 

Method Source Code

//package com.java2s;
import java.util.Collection;

public class Main {
    public static final String EMPTY = "";
    private static final String DELIMITER = ", ";

    /**/* w  w w.  j  a v a 2s .c  o m*/
     * Transforms a collection of Integers into a comma delimited String. If the
     * given collection of elements are null or is empty, an empty String is
     * returned.
     * 
     * @param elements the collection of Integers
     * @return a comma delimited String.
     */
    public static String getCommaDelimitedString(Collection<?> elements) {
        final StringBuilder builder = new StringBuilder();

        if (elements != null && !elements.isEmpty()) {
            for (Object element : elements) {
                builder.append(element.toString()).append(DELIMITER);
            }

            return builder.substring(0, builder.length() - DELIMITER.length());
        }

        return builder.toString();
    }

    /**
     * Transforms a collection of Integers into a comma delimited String. If the
     * given collection of elements are null or is empty, an empty String is
     * returned.
     * 
     * @param delimitPrefix whether to prefix the string with a delimiter.
     * @param delimitSuffix whether to suffix the string with a delimiter.
     * @param elements the collection of Integers
     * @return a comma delimited String.
     */
    public static String getCommaDelimitedString(Collection<?> elements, boolean delimitPrefix,
            boolean delimitSuffix) {
        final StringBuilder builder = new StringBuilder();

        if (elements != null && !elements.isEmpty()) {
            if (delimitPrefix) {
                builder.append(DELIMITER);
            }

            builder.append(getCommaDelimitedString(elements));

            if (delimitSuffix) {
                builder.append(DELIMITER);
            }
        }

        return builder.toString();
    }

    /**
     * Null-safe method for writing the items of a string array out as a string
     * separated by the given char separator.
     * 
     * @param array the array.
     * @param separator the separator of the array items.
     * @return a string.
     */
    public static String toString(String[] array, String separator) {
        StringBuilder builder = new StringBuilder();

        if (array != null && array.length > 0) {
            for (String string : array) {
                builder.append(string).append(separator);
            }

            builder.deleteCharAt(builder.length() - 1);
        }

        return builder.toString();
    }

    /**
     * Returns the string representation of the object, or null if the object is
     * null.
     * 
     * @param object the object.
     * @return the string representation.
     */
    public static String toString(Object object) {
        return object != null ? object.toString() : null;
    }

    /**
     * Gets the sub string of the given string. If the beginIndex is larger than
     * the length of the string, the empty string is returned. If the beginIndex +
     * the length is larger than the length of the string, the part of the string
     * following the beginIndex is returned. Method is out-of-range safe.
     * 
     * @param string the string.
     * @param beginIndex the zero-based begin index.
     * @param length the length of the sub string starting at the begin index.
     * @return the sub string of the given string.
     */
    public static String subString(String string, int beginIndex, int length) {
        final int endIndex = beginIndex + length;

        if (beginIndex >= string.length()) {
            return EMPTY;
        }

        if (endIndex > string.length()) {
            return string.substring(beginIndex, string.length());
        }

        return string.substring(beginIndex, endIndex);
    }
}

Related

1. getCollectionClass(TT tt)
2. getCollectionClosingSymbol(Collection col)
3. getCollectionPreview(final Collection collection, int previewSize)
4. getCollectionSize(Collection collection)
5. getCollectionSize(Collection collection)
6. getCommaSeparatedString(Collection collection)
7. getCommaSeparatedString(Collection values)
8. getCommaSeparatedStringFromCollection(Collection collections)
9. getCommon(Collection c1, Collection c2)