src/main/java/com/tri/persistence/jpql/utils/StringUtils.java
public static String join(final List<String> list) {

		// zero, empty or one element
		if (list == null) {
			return null;
		} else if (list.size() == 0) {
			return "";
		} else if (list.size() == 1) {
			return list.get(0);
		}

		// two or more elements
		final StringBuilder builder = new StringBuilder();
		for (String item : list) {
			if (builder.length() > 0) {
				builder.append(", ");
			}
			builder.append(item);
		}
		return builder.toString();

	}
public static String join(final List<String> list) {

		// zero, empty or one element
		if (list == null) {
			return null;
		} else if (list.size() == 0) {
			return "";
		} else if (list.size() == 1) {
			return list.get(0);
		}

		// two or more elements
		final StringBuilder builder = new StringBuilder();
		for (String item : list) {
			if (builder.length() > 0) {
				builder.append(", ");
			}
			builder.append(item);
		}
		return builder.toString();

	}
Joins items of a text list, separating items by comma.

@param list
list of text items
@return joined list