Guava 다시 - 1

1. Guava Objects class 

http://www.tutorialspoint.com/guava/guava_objects_class.htm

package com.tisotry.tazz009.guava; import org.apache.commons.lang3.builder.ToStringBuilder; import org.apache.commons.lang3.builder.ToStringStyle; import com.google.common.base.Objects; public class Person { private final String name, nickname; private final Movie favMovie; public Person(String name, String nickname, Movie movie) { this.name = name; this.nickname = nickname; this.favMovie = movie; } public String getName() { return name; } public String getNickname() { return nickname; } public Movie getFavMovie() { return favMovie; } @Override public String toString() { return ToStringBuilder.reflectionToString(this, ToStringStyle.JSON_STYLE); } // Guava Style start ---> @Override public boolean equals(Object obj) { if (!(obj instanceof Person) || obj == null) { return false; } Person person = (Person) obj; return Objects.equal(name, person.name) && Objects.equal(nickname, person.nickname) && Objects.equal(favMovie, person.favMovie); } @Override public int hashCode() { return Objects.hashCode(name, nickname, favMovie); } // Guava Style end!!! ---> }

2. Guava Collections 

package com.tisotry.tazz009.guava; import java.util.ArrayList; import java.util.Arrays; import java.util.Collection; import java.util.Collections; import java.util.Iterator; import java.util.LinkedHashMap; import java.util.LinkedHashSet; import java.util.List; import java.util.Locale; import java.util.Map; import java.util.Set; import com.google.common.collect.ArrayListMultimap; import com.google.common.collect.HashMultimap; import com.google.common.collect.ImmutableMap; import com.google.common.collect.ImmutableSet; import com.google.common.collect.Multimap; import com.google.common.collect.SetMultimap; import static com.google.common.collect.Lists.*; public class StaticFactories { public static final Set<Locale> LOCALES = Collections .unmodifiableSet(new LinkedHashSet<Locale>( Arrays.asList(Locale.KOREA, Locale.JAPAN, Locale.GERMAN))); // Guava Style ImmutableSet ---> public static final Set<Locale> LOCALES_GUAVA = ImmutableSet.of( Locale.KOREA, Locale.JAPAN, Locale.GERMAN); public static final Map<Locale, Integer> LOCALE_RANKS; static { Map<Locale, Integer> ranks = new LinkedHashMap<Locale, Integer>(); ranks.put(Locale.KOREA, 1); ranks.put(Locale.JAPAN, 2); ranks.put(Locale.GERMAN, 3); LOCALE_RANKS = Collections.unmodifiableMap(ranks); } // Guava Style ImmutableMap ---> public static final Map<Locale, Integer> LOCALE_RANKS_GUAVA; static { // 방법 1 // ImmutableMap.Builder<Locale, Integer> ranks = ImmutableMap.builder(); // ranks.put(Locale.KOREA, 1); // ranks.put(Locale.JAPAN, 2); // ranks.put(Locale.GERMAN, 3); // LOCALE_RANKS_GUAVA = ranks.build(); // 방법 2 LOCALE_RANKS_GUAVA = ImmutableMap.<Locale, Integer> builder() .put(Locale.KOREA, 1) .put(Locale.JAPAN, 2) .put(Locale.GERMAN, 3) .build(); } public static void main(String[] args) { // 일반적인 ArrayList 객체 생성 List<Map<String, Object>> maps = new ArrayList<Map<String, Object>>(); // Guava를 사용한 ArrayList 객체 생성 List<Map<String, Object>> mapsWithGuava = newArrayList(); List<String> names = newArrayList("tazz001", "tazz002"); for (String name : names) { System.out.println(name); } Iterator<String> iterator = names.iterator(); ArrayList<String> names2 = newArrayList(iterator); for (String name : names2) { System.out.println(name); } for (Iterator<Locale> locales = LOCALES.iterator(); locales.hasNext();) { Locale locale = (Locale) locales.next(); System.out.println(locale); } for (Iterator<Locale> locales = LOCALES_GUAVA.iterator(); locales.hasNext();) { Locale locale = (Locale) locales.next(); System.out.println(locale); } // Guava Style Multimap ---> Multimap<String, String> myMultimap = ArrayListMultimap.create(); myMultimap.put("Fruits", "Banana"); myMultimap.put("Fruits", "Apple"); myMultimap.put("Fruits", "Apple"); myMultimap.put("Fruits", "Pear"); myMultimap.put("Vegetable", "Carrot"); int size = myMultimap.size(); System.out.println("size : " + size); Collection<String> fruits = myMultimap.get("Fruits"); System.out.println(fruits); Map<String, Collection<String>> asMap = myMultimap.asMap(); SetMultimap<String, String> myMultimap2 = HashMultimap.create(); myMultimap2.put("Fruits", "Banana"); myMultimap2.put("Fruits", "Apple"); myMultimap2.put("Fruits", "Apple"); myMultimap2.put("Fruits", "Pear"); myMultimap2.put("Vegetable", "Carrot"); Set<String> fruits2 = myMultimap2.get("Fruits"); System.out.println(fruits2); // Guava Style BiMap ---> BiMap<Integer, String> empIDNameMap = HashBiMap.create(); empIDNameMap.put(new Integer(101), "Mahesh"); empIDNameMap.put(new Integer(102), "Sohan"); empIDNameMap.put(new Integer(103), "Ramesh"); Set<Integer> keySet = empIDNameMap.keySet(); for (Integer key : keySet) { System.out.println(key); } BiMap<String, Integer> inverse = empIDNameMap.inverse(); System.out.println(inverse.get("Mahesh")); Set<String> keySetForInverse = inverse.keySet(); for (String key : keySetForInverse) { System.out.println(key); } // Guava Style Multiset ---> Multiset<String> multiset = HashMultiset.create(); multiset.add("a"); multiset.add("b"); multiset.add("c"); multiset.add("d"); multiset.add("a"); multiset.add("b"); multiset.add("c"); multiset.add("b"); multiset.add("b"); multiset.add("b"); System.out.println("Occurrence of 'b' : " + multiset.count("b")); System.out.println("Total Size : " + multiset.size()); Set<String> set = multiset.elementSet(); System.out.println("Set ["); for (String s : set) { System.out.println(s); } System.out.println("]"); Iterator<String> iterator3 = multiset.iterator(); System.out.println("MultiSet ["); while (iterator3.hasNext()) { System.out.println(iterator3.next()); } System.out.println("]"); // display the distinct elements of the multiset with their occurrence // count System.out.println("MultiSet ["); for (Multiset.Entry<String> entry : multiset.entrySet()) { System.out.println("Element: " + entry.getElement() + ", Occurrence(s): " + entry.getCount()); } System.out.println("]"); // remove extra occurrences multiset.remove("b", 2); // print the occurrence of an element System.out.println("Occurence of 'b' : " + multiset.count("b")); } }