share guava test file.

GuavaCollection2

import com.google.common.base.Predicates;
import com.google.common.collect.Collections2;

import java.util.Collection;
import java.util.HashSet;
import java.util.Set;

import static java.lang.System.out;

    /**
     * Class whose sole reason for existence is to demonstrate Guava's Collections2
     * class.
     *
     * @author Dustin
     * @see http://marxsoftware.blogspot.com/2011/10/filtering-and-transforming-java.html
     */
    public class GuavaCollection2 {

        /**
         * Provides a Set of Strings.
         *
         * @return Set of strings representing some programming languages.
         */
        private static Set<String> buildSetStrings() {
            final Set<String> strings = new HashSet<String>();
            strings.add("Java");
            strings.add("Groovy");
            strings.add("Jython");
            strings.add("JRuby");
            strings.add("Python");
            strings.add("Ruby");
            strings.add("Perl");
            strings.add("C");
            strings.add("C++");
            strings.add("C#");
            strings.add("Pascal");
            strings.add("Fortran");
            strings.add("Cobol");
            strings.add("Scala");
            strings.add("Clojure");
            strings.add("Basic");
            strings.add("PHP");
            strings.add("Flex/ActionScript");
            strings.add("JOVIAL");
            return strings;
        }

        /**
         * Demonstrate Guava's Collections2.filter method. Filter String beginning
         * with letter 'J'.
         */
        public static void demonstrateFilter() {
            printHeader("Collections2.filter(Collection,Predicate): 'J' Languages");
            final Set<String> strings = buildSetStrings();
            out.println("\nOriginal Strings (pre-filter):\n\t" + strings);
            final Collection<String> filteredStrings = Collections2.filter(strings,
                    Predicates.containsPattern("^J"));
            out.println("\nFiltered Strings:\n\t" + filteredStrings);
            out.println("\nOriginal Strings (post-filter):\n\t" + strings);
        }

        /**
         * Demonstrate Guava's Collections2.transform method. Transform input
         * collection's entries to uppercase form.
         */
        public static void demonstrateTransform() {
            printHeader("Collections2.transform(Collection,Function): Uppercase");
            final Set<String> strings = buildSetStrings();
            out.println("\nOriginal Strings (pre-transform):\n\t" + strings);
            // final Collection<String> transformedStrings = Collections2.transform(
            //        strings, new UpperCaseFunction<String, String>());
            // out.println("\nTransformed Strings:\n\t" + transformedStrings);
            out.println("\nOriginal Strings (post-transform):\n\t" + strings);
        }

        /**
         * Print a separation header including the provided text.
         *
         * @param headerText
         * Text to be included in separation header.
         */
        private static void printHeader(final String headerText) {
            out.println("\n==========================================================");
            out.println("== " + headerText);
            out.println("==========================================================");
        }

        /**
         * Main function for demonstrating Guava's Collections2 class.
         *
         * @param arguments
         */
        public static void main(final String[] arguments) {
            demonstrateFilter();
            demonstrateTransform();
        }

    }