集合クラスの整理
集合クラス関係図は次のとおりです.
一、SET:
① EnumSet
印刷結果:
② LinkedHashSet
印刷結果:
③ TreeSet
印刷結果:
二、List
① LinkedList
印刷結果:
② vector
印刷結果:
三、queue
① ProrityQueue
印刷結果:
四map
① EnumMap
印刷結果:
② hashtable
印刷結果:
③ IdentityHashMap
印刷結果:
④ LinkedHashMap
印刷結果:
⑤ properties
印刷結果
⑥ TreeMap
印刷結果:
⑦ WeakHashMap
印刷結果
一、SET:
① EnumSet
package set;
import java.util.EnumSet;
import java.util.HashSet;
import java.util.Set;
/*
* DESCRIPTION :
* USER : zhouhui
* DATE : 2017/8/18 12:05
*/
public class EnumSetTest {
/**
* EnumSet set ,
* hashset , EnumSet
* EnumSet , AbstractSet,AbstractSet Set
*/
public static void main(String[] args) {
System.out.println("EnumSet.noneOf");
Set set=EnumSet.noneOf(Student.class);
set.add(Student.HARRY);
set.add(Student.ROBBIE);
set.add(Student.ROBIN);
for(Student p:set){
System.out.println(p);
}
set.clear();
System.out.println();
System.out.println("EnumSet.allOf");
set=EnumSet.allOf(Student.class);
for(Student p:set){
System.out.println(p);
}
set.clear();
System.out.println();
System.out.println("EnumSet.Of one");
set=EnumSet.of(Student.ROBIN);
for(Student p:set){
System.out.println(p);
}
System.out.println();
System.out.println("EnumSet.Of two");
set=EnumSet.of(Student.ROBIN,Student.HARRY);
for(Student p:set){
System.out.println(p);
}
System.out.println();
System.out.println("hashset:");
Set set2 = new HashSet();
set2.add(Student.HARRY);
set2.add(Student.ROBBIE);
set2.add(Student.ROBIN);
for (Student student : set2){
System.out.println(student);
}
}
}
enum Student
{
ROBIN("robin"),
HARRY("harry",40),
ROBBIE("robbie");
String name;
int age;
private Student(String name)
{
this(name,0);
}
private Student(String name,int age)
{
this.name=name;
this.age=age;
}
public String toString()
{
return name;
}
}
印刷結果:
EnumSet.noneOf
robin
harry
robbie
EnumSet.allOf
robin
harry
robbie
EnumSet.Of one
robin
EnumSet.Of two
robin
harry
hashset:
robbie
robin
harry
② LinkedHashSet
package set;
import java.util.LinkedHashSet;
import java.util.Set;
/*
* DESCRIPTION :
* USER : zhouhui
* DATE : 2017/8/18 14:35
*/
public class LinkedHashSetTest {
/**
* LinkedHashSet set, , 。
* , add
*/
public static void main(String[] args) {
Set set = new LinkedHashSet();
set.add(1);
set.add(5);
set.add(2);
set.add(1);
for(Integer i : set){
System.out.println(i);
}
}
}
印刷結果:
1
5
2
③ TreeSet
package set;
import java.util.Comparator;
import java.util.Set;
import java.util.TreeSet;
/*
* DESCRIPTION :
* USER : zhouhui
* DATE : 2017/8/18 12:27
*/
public class TreeSetTest {
/**
* TreeSet , NavigableSet,NavigableSet SortedSet ,SortedSet Set
* , , Comparator compare
* Map
*/
public static void main(String[] args) {
Set set = new TreeSet(new Comparator() {
public int compare(Integer o1, Integer o2) {
return o2 - o1;
}
});
set.add(2);
set.add(1);
set.add(3);
for(Integer i : set){
System.out.println(i);
}
}
}
印刷結果:
3
2
1
二、List
① LinkedList
package list;
import java.util.LinkedList;
import java.util.List;
/*
* DESCRIPTION :
* USER : zhouhui
* DATE : 2017/8/18 15:22
*/
public class LinkedListTest {
/**
* LinkedList ArrayList
* LinkedList ,ArrayList ( , ) 。
* ,ArrayList LinkedList 。
* ,LinkedList ArrayList , ArrayList , , ,LinkedList ,
*/
public static void main(String[] args) {
List list = new LinkedList();
list.add(1);
list.add(2);
for(Integer i : list){
System.out.println(i);
}
}
}
印刷結果:
1
2
② vector
package list;
import java.util.List;
import java.util.Vector;
/*
* DESCRIPTION :
* USER : zhouhui
* DATE : 2017/8/18 15:41
*/
public class VectorTest {
/**
* Vector List , ArrayList , 。
*
*
*/
public static void main(String[] args) {
List list = new Vector();
list.add(1);
list.add(2);
for(Integer i : list){
System.out.println(i);
}
}
}
印刷結果:
1
2
三、queue
① ProrityQueue
package queue;
import java.util.Comparator;
import java.util.PriorityQueue;
/*
* DESCRIPTION :
* USER : zhouhui
* DATE : 2017/8/18 17:28
*/
public class ProrityQueueTest {
public static void main(String[] args) {
PriorityQueue priorityQueue = new PriorityQueue(2,new Comparator() {
public int compare(Boss o1, Boss o2) {
return o2.getAge() - o1.getAge();
}
});
priorityQueue.add(new Boss("zhouhui",28));
priorityQueue.add(new Boss("zhangjingjing",26));
for(Boss boss : priorityQueue){
System.out.println(boss.toString());
}
}
}
class Boss{
private String name;
private Integer age;
public Boss(String name, Integer age) {
this.name = name;
this.age = age;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public Integer getAge() {
return age;
}
public void setAge(Integer age) {
this.age = age;
}
@Override
public String toString() {
return "Boss{" +
"name='" + name + '\'' +
", age=" + age +
'}';
}
}
印刷結果:
Boss{name='zhouhui', age=28}
Boss{name='zhangjingjing', age=26}
四map
① EnumMap
package map;
import java.util.EnumMap;
import java.util.Map;
/*
* DESCRIPTION :
* USER : zhouhui
* DATE : 2017/8/18 15:46
*/
public class EnumMapTest {
/**
* EnumMap key
*/
public static void main(String[] args) {
Map map = new EnumMap(Student.class);
map.put(Student.HARRY,Student.HARRY.toString());
map.put(Student.ROBBIE,Student.ROBBIE.toString());
map.put(Student.ROBIN,Student.ROBIN.toString());
for(Map.Entry entry : map.entrySet()){
System.out.println(entry.getKey().name + ":" + entry.getValue());
}
}
}
enum Student
{
ROBIN("robin"),
HARRY("harry",40),
ROBBIE("robbie");
String name;
int age;
private Student(String name)
{
this(name,0);
}
private Student(String name,int age)
{
this.name=name;
this.age=age;
}
public String toString()
{
return name;
}
}
印刷結果:
robin:robin
harry:harry
robbie:robbie
② hashtable
package map;
import java.util.Collections;
import java.util.HashMap;
import java.util.Hashtable;
import java.util.Map;
/*
* DESCRIPTION :
* USER : zhouhui
* DATE : 2017/8/18 16:14
*/
public class HashTableTest {
/**
* hashtable hashmap :
* 1,hashtable ,hashmap
* 2,hashmap key value null ,hashtable
* 3,hashmap Collections.synchronizedMap(map)
*/
public static void main(String[] args) {
Hashtable hashtable = new Hashtable();
for (int i = 0; i entry : hashtable.entrySet()){
System.out.println(entry.getKey() + ":" + entry.getValue());
}
Map map = new HashMap();
map.put(1,12);
map = Collections.synchronizedMap(map);
}
}
印刷結果:
9:9
8:8
7:7
6:6
5:5
4:4
3:3
2:2
1:1
0:0
③ IdentityHashMap
package map;
import java.util.HashMap;
import java.util.IdentityHashMap;
import java.util.Map;
/*
* DESCRIPTION :
* USER : zhouhui
* DATE : 2017/8/18 15:57
*/
public class IdentityHashMapTest {
/**
* IdentityHashMap key ==, HashMap toString
* "1" String.valueOf("1"), new String("1") ,IdentityHashMap , HashMap 。
*/
public static void main(String[] args) {
Map map = new IdentityHashMap();
map.put("1","2");
map.put(new String("1"),"2");
for(Map.Entry entry : map.entrySet()){
System.out.println(entry.getKey() + ":" + entry.getValue());
}
System.out.println("---------------------");
map = new HashMap();
map.put(String.valueOf("1"),"2");
map.put(new String("1"),"2");
for(Map.Entry entry : map.entrySet()){
System.out.println(entry.getKey() + ":" + entry.getValue());
}
}
}
印刷結果:
1:2
1:2
---------------------
1:2
④ LinkedHashMap
package map;
import java.util.Map;
/*
* DESCRIPTION :
* USER : zhouhui
* DATE : 2017/8/18 16:09
*/
public class LinkedHashMapTest {
/**
* map 。
*/
public static void main(String[] args) {
Map map = new java.util.LinkedHashMap();
map.put(1,3);
map.put(2,3);
map.put(3,3);
for(Map.Entry entry : map.entrySet()){
System.out.println(entry.getKey() + ":" + entry.getValue());
}
}
}
印刷結果:
1:3
2:3
3:3
⑤ properties
package map;
import java.util.Map;
import java.util.Properties;
/*
* DESCRIPTION :
* USER : zhouhui
* DATE : 2017/8/18 16:26
*/
public class PropertiesTest {
/**
* properties hashtable, key value string , put(Object,Object) , toString String,String。
*
* properties load ,getProperty(String key)
*/
public static void main(String[] args) {
Properties properties = new Properties();
properties.put(new Boss("zhou",1),new Boss("zhang",12));
for(Map.Entry
印刷結果
Boss{name='zhou', age=1}:Boss{name='zhang', age=12}
⑥ TreeMap
package map;
import java.util.Comparator;
import java.util.Map;
import java.util.TreeMap;
/*
* DESCRIPTION :
* USER : zhouhui
* DATE : 2017/8/18 16:53
*/
public class TreeMapTest {
/**
* TreeMap key map
*/
public static void main(String[] args) {
Map map = new TreeMap(new Comparator() {
public int compare(Integer o1, Integer o2) {
return o2 - o1;
}
});
map.put(1,2);
map.put(2,3);
map.put(3,1);
for(Map.Entry entry : map.entrySet()){
System.out.println(entry.getKey() + ":" + entry.getValue());
}
}
}
印刷結果:
3:1
2:3
1:2
⑦ WeakHashMap
package map;
import java.util.Map;
import java.util.WeakHashMap;
/*
* DESCRIPTION :
* USER : zhouhui
* DATE : 2017/8/18 17:03
*/
public class WeakHashMapTest {
/**
* weakhashmap hashmap :
* weakhashmap key , 。
*/
public static void main(String[] args) {
String a = new String("1");
Map map = new WeakHashMap();
map.put(a,"2");
for(Map.Entry entry : map.entrySet()){
System.out.println(entry.getKey() + ":" + entry.getValue());
}
System.out.println("--------------------------------------");
a = null;
System.gc();
for(Map.Entry entry : map.entrySet()){
System.out.println(entry.getKey() + ":" + entry.getValue());
}
}
}
印刷結果
1:2
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