《Java编程思想》第十一章 持有对象

 1 package pets;
 2 /** 
 3  * @author zlz099: 
 4  * @version 创建时间：2017年9月29日 上午10:37:12 
 5  */
 6 public class Pet extends Individual{
 7     public Pet(String name){
 8         super(name);
 9     }
10     public Pet(){super();}
11 }

 1 package pets;
 2 
 3 import java.util.*;
 4 
 5 /** 
 6  * @author zlz099: 
 7  * @version 创建时间：2017年9月29日 下午4:26:29 
 8  */
 9 public class PetCount {
10     static class PetCounter extends HashMap<String,Integer>{
11         public void count(String type){
12             Integer quantity = get(type);
13             if(quantity == null)
14                 put(type, 1);
15             else {
16                 put(type, quantity+1);
17             }
18         }
19     }
20     public static void countPets(PetCreator creator){
21         PetCounter counter = new PetCounter();
22         for(Pet pet :creator.createArray(20)){
23             System.out.println(pet.getClass().getSimpleName()+" ");
24             if(pet instanceof Pet)
25                 counter.count("Pet");
26             if(pet instanceof Dog)
27                 counter.count("Dog");
28             if(pet instanceof Mutt)
29                 counter.count("Mutt");
30             if(pet instanceof Pug)
31                 counter.count("Pug");
32             if(pet instanceof Cat)
33                 counter.count("Cat");
34             if(pet instanceof Manx)
35                 counter.count("EgyptianMau");
36             if(pet instanceof Manx)
37                 counter.count("Manx");
38             if(pet instanceof Manx)
39                 counter.count("Cymric");
40             if(pet instanceof Rodent)
41                 counter.count("Rodent");
42             if(pet instanceof Rat)
43                 counter.count("Rat");
44             if(pet instanceof Mouse)
45                 counter.count("Mouse");
46             if(pet instanceof Hamster)
47                 counter.count("Hamster");    
48         }
49         System.out.println();
50         System.out.println(counter);
51     }
52     public static void main(String[] args) {
53         // TODO Auto-generated method stub
54         countPets(new ForNameCreator());
55     }
56 
57 }

 1 package pets;
 2 
 3 import java.util.*;
 4 
 5 /** 
 6  * @author zlz099: 
 7  * @version 创建时间：2017年9月29日 上午10:47:13 
 8  */
 9 public abstract class PetCreator {
10     private Random rand = new Random(47);
11     public abstract List<Class<?extends Pet>> types();
12     public Pet randomPet(){
13         int n = rand.nextInt(types().size());
14         try {
15             return types().get(n).newInstance();
16         } catch (InstantiationException e) {
17             // TODO: handle exception
18             throw new RuntimeException(e);
19         }catch (IllegalAccessException e) {
20             // TODO: handle exception
21             throw new RuntimeException(e);
22         }
23     }
24     public Pet[] createArray(int size){
25         Pet[] result = new Pet[size];
26         for(int i = 0; i< size; i++)
27             result[i] = randomPet();
28         return result;
29     }
30     public ArrayList<Pet> arrayList(int size){
31         ArrayList<Pet> result = new ArrayList<Pet>();
32         Collections.addAll(result, createArray(size));
33         return result;
34     }
35 }

 1 package pets;
 2 
 3 import java.util.*;
 4 
 5 /** 
 6  * @author zlz099: 
 7  * @version 创建时间：2017年9月29日 上午10:57:34 
 8  */
 9 public class ForNameCreator extends PetCreator{
10 
11     private static List<Class<? extends Pet>> types = new ArrayList<Class<? extends Pet>>();
12     private static String[] typeNames = {
13         "typeinfo.Pets.Mutt",
14         "typeinfo.Pets.Pug",
15         "typeinfo.Pets.EgyptianMau",
16         "typeinfo.Pets.Manx",
17         "typeinfo.Pets.Cumric",
18         "typeinfo.Pets.Rat",
19         "typeinfo.Pets.Mouse",
20         "typeinfo.Pets.Hamster"
21     };
22     @SuppressWarnings("unchecked")
23     private static void loader(){
24         try {
25             for(String name : typeNames)
26                 types.add((Class<? extends Pet>)Class.forName(name));
27         } catch (ClassNotFoundException e) {
28             // TODO: handle exception
29             throw new RuntimeException(e);
30         }
31     }
32     static {loader();}
33     @Override
34     public List<Class<? extends Pet>> types() {
35         // TODO Auto-generated method stub
36         return types;
37     }
38     
39 }

 1 package pets;
 2 
 3 import java.util.*;
 4 
 5 /** 
 6  * @author zlz099: 
 7  * @version 创建时间：2017年9月29日 上午10:57:34 
 8  */
 9 public class ForNameCreator extends PetCreator{
10 
11     private static List<Class<? extends Pet>> types = new ArrayList<Class<? extends Pet>>();
12     private static String[] typeNames = {
13         "typeinfo.Pets.Mutt",
14         "typeinfo.Pets.Pug",
15         "typeinfo.Pets.EgyptianMau",
16         "typeinfo.Pets.Manx",
17         "typeinfo.Pets.Cumric",
18         "typeinfo.Pets.Rat",
19         "typeinfo.Pets.Mouse",
20         "typeinfo.Pets.Hamster"
21     };
22     @SuppressWarnings("unchecked")
23     private static void loader(){
24         try {
25             for(String name : typeNames)
26                 types.add((Class<? extends Pet>)Class.forName(name));
27         } catch (ClassNotFoundException e) {
28             // TODO: handle exception
29             throw new RuntimeException(e);
30         }
31     }
32     static {loader();}
33     @Override
34     public List<Class<? extends Pet>> types() {
35         // TODO Auto-generated method stub
36         return types;
37     }
38     
39 }

 1 package pets;
 2 /** 
 3  * @author zlz099: 
 4  * @version 创建时间：2017年9月29日 上午10:21:44 
 5  */
 6 public class Individual implements Comparable<Individual>{
 7 
 8     private static long counter = 0;
 9     private final long id = counter++;
10     private String name;
11     public Individual(String name){this.name = name;}
12     public Individual(){}
13     public String toString(){return getClass().getSimpleName()+(name == null?"":" "+name);}
14     public long id(){return id;}
15     public boolean equals(Object o){return o instanceof Individual && id ==((Individual)o).id;}
16     public int hashCode(){
17         int result = 17;
18         if(name != null)
19             result = 37*result+name.hashCode();
20         result = 37*result + (int)id;
21         return result;
22     }
23     @Override
24     public int compareTo(Individual arg) {
25         // TODO Auto-generated method stub
26         String first = getClass().getSimpleName();
27         String argFirst = arg.getClass().getSimpleName();
28         int firstCompare = first.compareTo(argFirst);
29         if(firstCompare != 0)
30             return firstCompare;
31         if(name != null && arg.name!=null){
32             int secondCompare = name.compareTo(arg.name);
33             if(secondCompare!=0)
34                 return secondCompare;
35         }
36         return (arg.id<id?-1:(arg.id == id?0:1));
37     }
38     
39 }

 1 package pets;
 2 /** 
 3  * @author zlz099: 
 4  * @version 创建时间：2017年9月29日 上午10:21:44 
 5  */
 6 public class Individual implements Comparable<Individual>{
 7 
 8     private static long counter = 0;
 9     private final long id = counter++;
10     private String name;
11     public Individual(String name){this.name = name;}
12     public Individual(){}
13     public String toString(){return getClass().getSimpleName()+(name == null?"":" "+name);}
14     public long id(){return id;}
15     public boolean equals(Object o){return o instanceof Individual && id ==((Individual)o).id;}
16     public int hashCode(){
17         int result = 17;
18         if(name != null)
19             result = 37*result+name.hashCode();
20         result = 37*result + (int)id;
21         return result;
22     }
23     @Override
24     public int compareTo(Individual arg) {
25         // TODO Auto-generated method stub
26         String first = getClass().getSimpleName();
27         String argFirst = arg.getClass().getSimpleName();
28         int firstCompare = first.compareTo(argFirst);
29         if(firstCompare != 0)
30             return firstCompare;
31         if(name != null && arg.name!=null){
32             int secondCompare = name.compareTo(arg.name);
33             if(secondCompare!=0)
34                 return secondCompare;
35         }
36         return (arg.id<id?-1:(arg.id == id?0:1));
37     }
38     
39 }

 1 package pets;
 2 
 3 import java.util.List;
 4 import java.io.ObjectOutputStream.PutField;
 5 import java.util.Arrays;
 6 import java.util.Collections;
 7 
 8 /** 
 9  * @author zlz099: 
10  * @version 创建时间：2017年9月29日 下午4:53:45 
11  */
12 public class LiteralPetCreator extends PetCreator{
13     @SuppressWarnings("unchecked")
14     public static final List<Class<? extends Pet>> allTypes = Collections.unmodifiableList(Arrays.asList(
15             Pet.class,Dog.class,Cat.class,Rodent.class,Mutt.class,Pug.class,EgyptianMau.class,
16             Manx.class,Cymric.class,Rat.class,Mouse.class,Hamster.class
17             ));
18     private static final List<Class<? extends Pet>> types = 
19             allTypes.subList(allTypes.indexOf(Mutt.class),allTypes.size());
20     public List<Class<? extends Pet>> types(){
21         return types;
22     }
23     public static void main(String[] args) {
24         // TODO Auto-generated method stub
25         System.out.println(types);
26     }
27 
28 }

 1 import java.util.ArrayList;
 2 import java.util.Arrays;
 3 import java.util.Collection;
 4 import java.util.Iterator;
 5 
 6 /** 
 7  * @author zlz099: 
 8  * @version 创建时间：2017年10月12日 下午5:29:30 
 9  */
10 class ReversibleArrayList<T> extends ArrayList<T>{
11     public ReversibleArrayList(Collection<T> c){super(c);}
12     public Iterable<T> reversed(){
13         return new Iterable<T>() {
14             public Iterator<T> iterator() {
15             return new Iterator<T>(){
16                 int current = size()-1;
17                 public boolean hasNext(){return current>-1;}
18                 public T next(){return get(current--);}
19                 public void remove(){throw new UnsupportedOperationException();}
20             };
21             }
22         };
23     }
24 }
25 public class AdapterMethodIdiom {
26     
27     public static void main(String[] args) {
28         // TODO Auto-generated method stub
29         ReversibleArrayList<String> ral = new ReversibleArrayList<String>(Arrays.asList("To be or not to be".split(" ")));
30         for(String s : ral)
31             System.out.print(s+" ");
32         System.out.println();
33         for(String s : ral.reversed())
34             System.out.print(s+" ");
35     }
36 
37 }

 1 import java.util.*;
 2 /** 
 3  * @author zlz099: 
 4  * @version 创建时间：2017年9月28日 上午10:36:38 
 5  */
 6 public class AddingGroups {
 7 
 8     public static void main(String[] args) {
 9         // TODO Auto-generated method stub
10         Collection<Integer> collection = new ArrayList<Integer>(Arrays.asList(1,2,3,4,5));
11         System.out.println(collection);
12         Integer[] moreInts = {6,7,8,9,10};
13         collection.addAll(Arrays.asList(moreInts));
14         System.out.println(collection);
15         Collections.addAll(collection, 11,12,13,14,15);
16         System.out.println(collection);
17         Collections.addAll(collection, moreInts);
18         System.out.println(collection);
19         List<Integer> list = Arrays.asList(16,17,18,19,20);
20         System.out.println(list);
21         list.set(1, 99);
22         System.out.println(list);
23         //list.add(11);
24         //System.out.println(list); 不能进行delete和add操作，因为底层表示的是数组。
25     }
26 
27 }

 1 import java.util.ArrayList;
 2 
 3 /** 
 4  * @author zlz099: 
 5  * @version 创建时间：2017年9月27日 下午9:56:43 
 6  * generic   商标
 7  */
 8 class Apple{
 9     private static long counter;
10     private final long id = counter++;
11     public long id(){return id;}
12 }
13 
14 class Orange{}
15 
16 public class ApplesAndOrangesWithoutGenerics {
17     @SuppressWarnings("unckecks")
18     public static void main(String[] args){
19         ArrayList<Apple> apples = new ArrayList<Apple>();
20         for(int i = 0; i< 3; i++)
21             apples.add(new Apple());
22         //apples.add(new Orange());   编译时出错，编译器阻止将Orange放入Apple
23         for(int i = 0 ; i<apples.size();i++)
24             //((Apple)apples.get(i)).id();
25             System.out.println(((Apple)apples.get(i)).id());
26         for(Apple c : apples)
27             System.out.println(c.id());
28     }
29 }

 1 import java.util.Arrays;
 2 
 3 /** 
 4  * @author zlz099: 
 5  * @version 创建时间：2017年10月12日 下午5:09:11 
 6  */
 7 public class ArrayIsNotIterable {
 8     static <T> void test(Iterable<T> ib){
 9         for(T t : ib)
10             System.out.print(t+" ");
11     }
12     public static void main(String[] args) {
13         // TODO Auto-generated method stub
14         test(Arrays.asList(1,2,3));
15         String[] strings = {"A","B","C"};
16         test(Arrays.asList(strings));
17     }
18 
19 }

 1 import java.util.ArrayList;
 2 import java.util.Collections;
 3 import java.util.List;
 4 import java.util.Arrays;
 5 
 6 /** 
 7  * @author zlz099: 
 8  * @version 创建时间：2017年9月28日 上午10:52:56 
 9  */
10 class Snow{}
11 class Power extends Snow{}
12 class Light extends Power{}
13 class Heavy extends Power{}
14 class Crusty extends Snow{}
15 class Slush extends Snow{}
16 public class AsListInterface {
17 
18     public static void main(String[] args) {
19         // TODO Auto-generated method stub
20         List<Snow> snow1 = Arrays.asList(new Crusty(),new Slush(),new Power());
21         List<Snow> snow3 = new ArrayList<Snow>();
22         Collections.addAll(snow3,new Light(),new Heavy());
23         List<Snow> snow4 = Arrays.<Snow>asList(new Light(),new Heavy());
24         System.out.println(snow1);
25         System.out.println(snow3);
26         System.out.println(snow4);
27     }
28 
29 }

 1 import java.nio.channels.UnsupportedAddressTypeException;
 2 import java.util.AbstractCollection;
 3 import java.util.Iterator;
 4 
 5 import pets.*;
 6 
 7 /** 
 8  * @author zlz099: 
 9  * @version 创建时间：2017年10月11日 下午4:08:32 
10  * @param <E>
11  */
12 public class CollectionSequence extends AbstractCollection<Pet>{
13     private Pet[] pets = Pets.createArray(8);
14     public int size() {
15         // TODO Auto-generated method stub
16         return pets.length;
17     }
18     public Iterator<Pet> iterator() {
19         // TODO Auto-generated method stub
20         return new Iterator<Pet>() {
21             private int index = 0;
22             public boolean hasNext(){
23                 return index < pets.length;
24             }
25             public Pet next(){return pets[index++];}
26             public void remove(){throw new UnsupportedOperationException();}
27         };
28     }
29     public static void main(String[] args) {
30         // TODO Auto-generated method stub
31         CollectionSequence c = new CollectionSequence();
32         InterfaceVsIterator.display(c);
33         InterfaceVsIterator.display(c.iterator());
34     }
35 }

 1 import java.nio.channels.UnsupportedAddressTypeException;
 2 import java.util.AbstractCollection;
 3 import java.util.Iterator;
 4 
 5 import pets.*;
 6 
 7 /** 
 8  * @author zlz099: 
 9  * @version 创建时间：2017年10月11日 下午4:08:32 
10  * @param <E>
11  */
12 public class CollectionSequence extends AbstractCollection<Pet>{
13     private Pet[] pets = Pets.createArray(8);
14     public int size() {
15         // TODO Auto-generated method stub
16         return pets.length;
17     }
18     public Iterator<Pet> iterator() {
19         // TODO Auto-generated method stub
20         return new Iterator<Pet>() {
21             private int index = 0;
22             public boolean hasNext(){
23                 return index < pets.length;
24             }
25             public Pet next(){return pets[index++];}
26             public void remove(){throw new UnsupportedOperationException();}
27         };
28     }
29     public static void main(String[] args) {
30         // TODO Auto-generated method stub
31         CollectionSequence c = new CollectionSequence();
32         InterfaceVsIterator.display(c);
33         InterfaceVsIterator.display(c.iterator());
34     }
35 }

 1 import java.util.ArrayList;
 2 import java.util.HashSet;
 3 import java.util.Iterator;
 4 import java.util.LinkedList;
 5 import java.util.TreeSet;
 6 
 7 import pets.*;
 8 
 9 
10 /** 
11  * @author zlz099: 
12  * @version 创建时间：2017年10月9日 上午11:25:06 
13  */
14 public class CrossContainerIteration {
15 
16     public static void display(Iterator<Pet> it){
17         while(it.hasNext()){
18             Pet p = it.next();
19             System.out.print(p.id()+":"+p+" ");
20         }
21         System.out.println();
22     }
23     public static void main(String[] args) {
24         // TODO Auto-generated method stub
25         ArrayList<Pet> pets = Pets.arrayList(8);
26         LinkedList<Pet> petsLL = new LinkedList<Pet>(pets);
27         HashSet<Pet> petsHS = new HashSet<Pet>(pets);
28         TreeSet<Pet> petsTS = new TreeSet<Pet>(pets);
29         
30         display(pets.iterator());
31         display(petsLL.iterator());
32         display(petsHS.iterator());
33         display(petsTS.iterator());
34     }
35 
36 }

 1 import java.util.Map;
 2 
 3 /** 
 4  * @author zlz099: 
 5  * @version 创建时间：2017年10月11日 下午5:18:58 
 6  */
 7 public class EnvironmentVariables {
 8 
 9     public static void main(String[] args) {
10         // TODO Auto-generated method stub
11         for(Map.Entry entry : System.getenv().entrySet()){
12             System.out.println(entry.getKey()+": "+entry.getValue());
13         }
14     }
15 }

 1 import java.util.Map;
 2 
 3 /** 
 4  * @author zlz099: 
 5  * @version 创建时间：2017年10月11日 下午5:18:58 
 6  */
 7 public class EnvironmentVariables {
 8 
 9     public static void main(String[] args) {
10         // TODO Auto-generated method stub
11         for(Map.Entry entry : System.getenv().entrySet()){
12             System.out.println(entry.getKey()+": "+entry.getValue());
13         }
14     }
15 }

 1 import java.util.*;
 2 
 3 import pets.*;
 4 
 5 /** 
 6  * @author zlz099: 
 7  * @version 创建时间：2017年10月11日 下午3:50:10 
 8  */
 9 public class InterfaceVsIterator {
10 
11     public static void display(Iterator<Pet> it){
12         while(it.hasNext()){
13             Pet p = it.next();
14             System.out.print(p.id()+":"+p+" ");
15         }
16         System.out.println();
17     }
18     public static void display(Collection<Pet> pets){
19         for(Pet p: pets)
20             System.out.print(p.id()+":"+p+" ");
21         System.out.println();
22     }
23     public static void main(String[] args) {
24         // TODO Auto-generated method stub
25         List<Pet> petList = Pets.arrayList(8);
26         Set<Pet> petSet = new HashSet<Pet>(petList);
27         Map<String, Pet> petMap = new LinkedHashMap<String,Pet>();
28         String[] names = ("Ralph,Eric,Robin,Lcaey, "+"Britney,Sam,Spot,Fluffy").split(",");
29         for(int i = 0; i < names.length; i++)
30             petMap.put(names[i], petList.get(i));
31         display(petList);
32         display(petSet);
33         display(petList.iterator());
34         display(petSet.iterator());
35         System.out.println(petMap);
36         System.out.println(petMap.keySet());
37         display(petMap.values());
38         display(petMap.values().iterator());
39         
40     }
41 
42 }

 1 import java.util.*;
 2 
 3 import pets.*;
 4 
 5 /** 
 6  * @author zlz099: 
 7  * @version 创建时间：2017年10月11日 下午3:50:10 
 8  */
 9 public class InterfaceVsIterator {
10 
11     public static void display(Iterator<Pet> it){
12         while(it.hasNext()){
13             Pet p = it.next();
14             System.out.print(p.id()+":"+p+" ");
15         }
16         System.out.println();
17     }
18     public static void display(Collection<Pet> pets){
19         for(Pet p: pets)
20             System.out.print(p.id()+":"+p+" ");
21         System.out.println();
22     }
23     public static void main(String[] args) {
24         // TODO Auto-generated method stub
25         List<Pet> petList = Pets.arrayList(8);
26         Set<Pet> petSet = new HashSet<Pet>(petList);
27         Map<String, Pet> petMap = new LinkedHashMap<String,Pet>();
28         String[] names = ("Ralph,Eric,Robin,Lcaey, "+"Britney,Sam,Spot,Fluffy").split(",");
29         for(int i = 0; i < names.length; i++)
30             petMap.put(names[i], petList.get(i));
31         display(petList);
32         display(petSet);
33         display(petList.iterator());
34         display(petSet.iterator());
35         System.out.println(petMap);
36         System.out.println(petMap.keySet());
37         display(petMap.values());
38         display(petMap.values().iterator());
39         
40     }
41 
42 }

 1 import java.util.Iterator;
 2 
 3 /** 
 4  * @author zlz099: 
 5  * @version 创建时间：2017年10月12日 下午9:32:39 
 6  */
 7 public class IterableClass implements Iterable<String>{
 8     protected String[] words = ("And that is how "+ "we know the Earth to be banana-shaped.").split(" ");
 9     
10     public Iterator<String> iterator() {
11         // TODO Auto-generated method stub
12         return new Iterator<String>() {
13             private int index = 0;
14             public boolean hasNext(){
15                 return index < words.length;
16             }
17             public String next(){return words[index++];}
18             public void remove(){throw new UnsupportedOperationException();}
19         };
20     }
21 
22     public static void main(String[] args){
23         for(String s : new IterableClass())
24             System.out.print(s+" ");
25     }
26 }

 1 import java.util.LinkedList;
 2 
 3 import pets.*;
 4 
 5 /** 
 6  * @author zlz099: 
 7  * @version 创建时间：2017年10月9日 下午9:25:28 
 8  */
 9 public class LinkedListFeatures {
10     
11     public static void main(String[] args) {
12         // TODO Auto-generated method stub
13         LinkedList<Pet> pets = new LinkedList<Pet>(Pets.arrayList(5));
14         System.out.print(pets);
15         System.out.print("pets.getFirst(): "+pets.getFirst());
16         System.out.print("pets.element(): "+pets.element());
17         System.out.print("pets.peek(): "+pets.peek());
18         System.out.print("pets.remove(): "+pets.remove());
19         System.out.print("pets.removeFirst(): "+pets.removeFirst());
20         System.out.print("pets.poll(): "+pets.poll());
21         System.out.print(pets);
22         pets.addFirst(new Rat());
23         System.out.print("After Add First(): "+pets);
24         
25         pets.offer(Pets.randomPet());
26         System.out.print("After Offer(): "+pets);
27         pets.add(Pets.randomPet());
28         
29         System.out.print("After add(): "+pets);
30         pets.addLast(new Hamster());
31         System.out.print("After addLast(): "+pets);
32         System.out.print("pets.removeLast(): "+pets.removeLast());
33     }
34 }

 1 /** 
 2  * @author zlz099: 
 3  * @version 创建时间：2017年9月28日 下午3:40:31 
 4  */
 5 import pets.*;
 6 
 7 import java.util.*;
 8 public class ListFeature {
 9 
10     public static void main(String[] args) {
11         // TODO Auto-generated method stub
12         Random rand = new Random(47);
13         List<Pet>pets = Pets.arrayList(7);
14         System.out.println("1: " + pets);
15         Hamster h = new Hamster();
16         pets.add(h);
17         System.out.println("2: "+pets);
18         System.out.println("3: "+pets.contains(h));  //contains()方法确定某个对象是否在列表中
19         pets.remove(h);  //remove()方法移除一个对象
20         Pet p = pets.get(2);
21         System.out.println("4: "+p+" "+pets.indexOf(p));  //indexof()方法发现该对象在List中所处的位置
22         Pet cymric = new Cymric();
23         System.out.println("5: "+pets.indexOf(cymric));
24         System.out.println("6: "+pets.remove(cymric)); 
25         System.out.println("7: "+pets.remove(p));
26         System.out.println("8: "+pets);
27         pets.add(3,new Mouse());
28         System.out.println("9: "+pets);
29         List<Pet> sub = pets.subList(1, 4);  //subList()方法允许从较大的列表中创建一个新的片段  这个片段传入containsAll()中肯定是true
30         System.out.println("subList: "+sub);
31         System.out.println("10: "+pets.containsAll(sub));
32         Collections.sort(sub);
33         System.out.println("sorted subList: "+sub);
34         System.out.println("11: "+pets.containsAll(sub));
35         Collections.shuffle(sub,rand);
36         System.out.println("12: "+pets.containsAll(sub));
37         List<Pet> copy = new ArrayList<Pet>(pets);
38         sub = Arrays.asList(pets.get(1),pets.get(4));
39         System.out.println("sub: "+sub);
40         copy.retainAll(sub);   //retainAll()是一种交集操作   同时保留copy和sub中的元素
41         System.out.println("13: "+copy);
42         copy = new ArrayList<Pet>(pets);
43         copy.remove(2);
44         System.out.println("14: "+copy);
45         copy.removeAll(sub);  //removeAll()也是基于equals的，从List中删除所有的元素
46         System.out.println("15: "+copy);
47         copy.set(1, new Mouse());
48         System.out.println("16: "+copy);
49         copy.addAll(2,sub);
50         System.out.println("17: "+copy);   
51         System.out.println("18: "+pets.isEmpty());
52         pets.clear();
53         System.out.println("19: "+pets);
54         System.out.println("20： "+pets.isEmpty());  //isEmpty和clear方法
55         pets.addAll(Pets.arrayList(4));
56         System.out.println("21: "+pets);
57         Object[] o = pets.toArray();
58         System.out.println("22: "+o[3]);
59         Pet[] pa = pets.toArray(new Pet[0]);  //toArray()方法将任意的Collection转化为一个数组
60         System.out.println("23: "+pa[3].id());
61         
62     }
63 
64 }

 1 /** 
 2  * @author zlz099: 
 3  * @version 创建时间：2017年9月28日 下午3:40:31 
 4  */
 5 import pets.*;
 6 
 7 import java.util.*;
 8 public class ListFeature {
 9 
10     public static void main(String[] args) {
11         // TODO Auto-generated method stub
12         Random rand = new Random(47);
13         List<Pet>pets = Pets.arrayList(7);
14         System.out.println("1: " + pets);
15         Hamster h = new Hamster();
16         pets.add(h);
17         System.out.println("2: "+pets);
18         System.out.println("3: "+pets.contains(h));  //contains()方法确定某个对象是否在列表中
19         pets.remove(h);  //remove()方法移除一个对象
20         Pet p = pets.get(2);
21         System.out.println("4: "+p+" "+pets.indexOf(p));  //indexof()方法发现该对象在List中所处的位置
22         Pet cymric = new Cymric();
23         System.out.println("5: "+pets.indexOf(cymric));
24         System.out.println("6: "+pets.remove(cymric)); 
25         System.out.println("7: "+pets.remove(p));
26         System.out.println("8: "+pets);
27         pets.add(3,new Mouse());
28         System.out.println("9: "+pets);
29         List<Pet> sub = pets.subList(1, 4);  //subList()方法允许从较大的列表中创建一个新的片段  这个片段传入containsAll()中肯定是true
30         System.out.println("subList: "+sub);
31         System.out.println("10: "+pets.containsAll(sub));
32         Collections.sort(sub);
33         System.out.println("sorted subList: "+sub);
34         System.out.println("11: "+pets.containsAll(sub));
35         Collections.shuffle(sub,rand);
36         System.out.println("12: "+pets.containsAll(sub));
37         List<Pet> copy = new ArrayList<Pet>(pets);
38         sub = Arrays.asList(pets.get(1),pets.get(4));
39         System.out.println("sub: "+sub);
40         copy.retainAll(sub);   //retainAll()是一种交集操作   同时保留copy和sub中的元素
41         System.out.println("13: "+copy);
42         copy = new ArrayList<Pet>(pets);
43         copy.remove(2);
44         System.out.println("14: "+copy);
45         copy.removeAll(sub);  //removeAll()也是基于equals的，从List中删除所有的元素
46         System.out.println("15: "+copy);
47         copy.set(1, new Mouse());
48         System.out.println("16: "+copy);
49         copy.addAll(2,sub);
50         System.out.println("17: "+copy);   
51         System.out.println("18: "+pets.isEmpty());
52         pets.clear();
53         System.out.println("19: "+pets);
54         System.out.println("20： "+pets.isEmpty());  //isEmpty和clear方法
55         pets.addAll(Pets.arrayList(4));
56         System.out.println("21: "+pets);
57         Object[] o = pets.toArray();
58         System.out.println("22: "+o[3]);
59         Pet[] pa = pets.toArray(new Pet[0]);  //toArray()方法将任意的Collection转化为一个数组
60         System.out.println("23: "+pa[3].id());
61         
62     }
63 
64 }

import java.util.List;
import java.util.ListIterator;

import pets.*;

/** 
 * @author zlz099: 
 * @version 创建时间：2017年10月9日 下午9:15:41 
 */
public class ListIteration {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        List<Pet> pets = Pets.arrayList(8);
        ListIterator<Pet> it = pets.listIterator();
        while(it.hasNext())
            System.out.println(it.next() + ", "+it.nextIndex()+", "+it.previousIndex()+"; ");
        System.out.println();
        while(it.hasPrevious())
            System.out.print(it.previous().id()+" ");
        System.out.println();
        System.out.println(pets);
        it = pets.listIterator(3);
        while(it.hasNext()){
            it.next();
            it.set(Pets.randomPet());
        }
        System.out.println(pets);
    }
}

import pets.*;

import java.util.*;

/** 
 * @author zlz099: 
 * @version 创建时间：2017年10月11日 上午11:12:10 
 */

public class MapOfList {
    public static Map<Person, List<? extends Pet>> petPeople 
        = new HashMap<Person, List<? extends Pet>>();
    static {
        petPeople.put(new Person("Dawn"), Arrays.asList(new Cymric("Holly"),new Mutt("Spot")));
        petPeople.put(new Person("Kate"), Arrays.asList(new Cat("Shackleton"),
                                          new Cat("Elsie May"),new Dog("Margrett")));
        petPeople.put(new Person("Marilyn"), Arrays.asList(new Pug("Louie aka Louis Snorkelstein Dupree"),
                                            new Cat("Stanford aka Stinky el Negro"),
                                          new Cat("Prinkola")));
        petPeople.put(new Person("Luke"), Arrays.asList(new Rat("Fussy"),new Rat("Fizzy")));
        petPeople.put(new Person("Isaac"), Arrays.asList(new Rat("Freckly")));
    }
    public static void main(String[] args){
        System.out.println("People: "+petPeople.keySet());
        System.out.println("Pets: "+petPeople.values());
        for(Person person: petPeople.keySet()){
            System.out.println(person+"has");
            for(Pet pet :petPeople.get(person))
                System.out.println("     "+pet);
        }
    }
}

 1 import pets.*;
 2 
 3 import java.util.*;
 4 
 5 /** 
 6  * @author zlz099: 
 7  * @version 创建时间：2017年10月11日 上午11:12:10 
 8  */
 9 
10 public class MapOfList {
11     public static Map<Person, List<? extends Pet>> petPeople 
12         = new HashMap<Person, List<? extends Pet>>();
13     static {
14         petPeople.put(new Person("Dawn"), Arrays.asList(new Cymric("Holly"),new Mutt("Spot")));
15         petPeople.put(new Person("Kate"), Arrays.asList(new Cat("Shackleton"),
16                                           new Cat("Elsie May"),new Dog("Margrett")));
17         petPeople.put(new Person("Marilyn"), Arrays.asList(new Pug("Louie aka Louis Snorkelstein Dupree"),
18                                             new Cat("Stanford aka Stinky el Negro"),
19                                           new Cat("Prinkola")));
20         petPeople.put(new Person("Luke"), Arrays.asList(new Rat("Fussy"),new Rat("Fizzy")));
21         petPeople.put(new Person("Isaac"), Arrays.asList(new Rat("Freckly")));
22     }
23     public static void main(String[] args){
24         System.out.println("People: "+petPeople.keySet());
25         System.out.println("Pets: "+petPeople.values());
26         for(Person person: petPeople.keySet()){
27             System.out.println(person+"has");
28             for(Pet pet :petPeople.get(person))
29                 System.out.println("     "+pet);
30         }
31     }
32 }

 1 import pets.*;
 2 
 3 import java.util.*;
 4 
 5 /** 
 6  * @author zlz099: 
 7  * @version 创建时间：2017年10月11日 上午11:12:10 
 8  */
 9 
10 public class MapOfList {
11     public static Map<Person, List<? extends Pet>> petPeople 
12         = new HashMap<Person, List<? extends Pet>>();
13     static {
14         petPeople.put(new Person("Dawn"), Arrays.asList(new Cymric("Holly"),new Mutt("Spot")));
15         petPeople.put(new Person("Kate"), Arrays.asList(new Cat("Shackleton"),
16                                           new Cat("Elsie May"),new Dog("Margrett")));
17         petPeople.put(new Person("Marilyn"), Arrays.asList(new Pug("Louie aka Louis Snorkelstein Dupree"),
18                                             new Cat("Stanford aka Stinky el Negro"),
19                                           new Cat("Prinkola")));
20         petPeople.put(new Person("Luke"), Arrays.asList(new Rat("Fussy"),new Rat("Fizzy")));
21         petPeople.put(new Person("Isaac"), Arrays.asList(new Rat("Freckly")));
22     }
23     public static void main(String[] args){
24         System.out.println("People: "+petPeople.keySet());
25         System.out.println("Pets: "+petPeople.values());
26         for(Person person: petPeople.keySet()){
27             System.out.println(person+"has");
28             for(Pet pet :petPeople.get(person))
29                 System.out.println("     "+pet);
30         }
31     }
32 }

 1 import java.util.ArrayList;
 2 import java.util.Arrays;
 3 import java.util.Random;
 4 import java.util.*;
 5 
 6 /** 
 7  * @author zlz099: 
 8  * @version 创建时间：2017年10月12日 下午9:55:13 
 9  */
10 public class ModifyingArraysAsList {
11     
12     public static void main(String[] args) {
13         // TODO Auto-generated method stub
14         Random rand = new Random(47);
15         Integer[] ia = {1,2,3,4,5,6,7,8,9,10};
16         List<Integer> list1 = new ArrayList<Integer>(Arrays.asList(ia));
17         System.out.println("Before shuffling: "+list1);
18         Collections.shuffle(list1,rand);
19         System.out.println("After shuffling: "+list1);
20         System.out.println("array: "+Arrays.toString(ia));
21         
22         List<Integer> list2 = Arrays.asList(ia);
23         System.out.println("Before shuffling: "+list2);
24         Collections.shuffle(list2,rand);
25         System.out.println("After shuffling: "+list2);
26         System.out.println("array: "+ Arrays.toString(ia));
27     }
28 
29 }

 1 import java.util.*;
 2 
 3 /** 
 4  * @author zlz099: 
 5  * @version 创建时间：2017年10月12日 下午9:30:02 
 6  */
 7 public class MultiIterableClass extends IterableClass{
 8     public Iterable<String> reversed(){
 9         return new Iterable<String>(){
10             public Iterator<String> iterator() {
11             return new Iterator<String>() {
12             int current = words.length -1;
13             public boolean hasNext(){return current > -1;}
14             public String next(){return words[current--];}
15             public void remove(){throw new UnsupportedOperationException();}
16             };
17             }
18         };
19     }
20     public Iterable<String> randomized(){
21         return new Iterable<String>() {
22             
23             @Override
24             public Iterator<String> iterator() {
25                 // TODO Auto-generated method stub
26                 List<String> shuffled = new ArrayList<String>(Arrays.asList(words));
27                 Collections.shuffle(shuffled,new Random(47));
28                 return shuffled.iterator();
29             }
30         };
31     }
32     public static void main(String[] args) {
33         // TODO Auto-generated method stub
34         MultiIterableClass mic = new MultiIterableClass();
35         for(String s : mic.reversed())
36             System.out.print(s+" ");
37         System.out.println();
38         for(String s : mic.randomized())
39             System.out.print(s+" ");
40         System.out.println();
41         for(String s : mic)
42             System.out.print(s);
43         System.out.println();
44     }
45 
46 }

 1 import java.util.Iterator;
 2 
 3 import org.omg.CORBA.NVList;
 4 
 5 import pets.*;
 6 
 7 /** 
 8  * @author zlz099: 
 9  * @version 创建时间：2017年10月11日 下午4:29:03 
10  */
11 class PetSequence{
12     protected Pet[] pets = Pets.createArray(8);
13 }
14 public class NonCollectionSequence extends PetSequence{
15     public Iterator<Pet> iterator(){
16         return new Iterator<Pet>() {
17             private int index = 0;
18             public boolean hasNext(){
19                 return index < pets.length;
20             }
21             public Pet next(){return pets[index++];}
22             public void remove(){throw new UnsupportedOperationException();}
23         };
24     }
25     public static void main(String[] args) {
26         // TODO Auto-generated method stub
27         NonCollectionSequence nc = new NonCollectionSequence();
28         InterfaceVsIterator.display(nc.iterator());
29     }
30 }

 1 import java.util.HashMap;
 2 import java.util.Map;
 3 
 4 import pets.*;
 5 
 6 /** 
 7  * @author zlz099: 
 8  * @version 创建时间：2017年10月11日 上午11:04:05 
 9  */
10 public class PetMap {
11 
12     public static void main(String[] args) {
13         // TODO Auto-generated method stub
14         Map<String,Pet> petMap = new HashMap<String, Pet>();
15         petMap.put("My Cat", new Cat("Molly"));
16         petMap.put("My Dog", new Dog("Ginger"));
17         petMap.put("My Hamster", new Hamster("Bosco"));
18         System.out.println(petMap);
19         Pet dog = petMap.get("My Dog");
20         System.out.println(dog);
21         System.out.println(petMap.containsKey("My Dog"));
22         System.out.println(petMap.containsValue(dog));
23         
24     }
25 
26 }

 1 import java.util.HashMap;
 2 import java.util.Map;
 3 
 4 import pets.*;
 5 
 6 /** 
 7  * @author zlz099: 
 8  * @version 创建时间：2017年10月11日 上午11:04:05 
 9  */
10 public class PetMap {
11 
12     public static void main(String[] args) {
13         // TODO Auto-generated method stub
14         Map<String,Pet> petMap = new HashMap<String, Pet>();
15         petMap.put("My Cat", new Cat("Molly"));
16         petMap.put("My Dog", new Dog("Ginger"));
17         petMap.put("My Hamster", new Hamster("Bosco"));
18         System.out.println(petMap);
19         Pet dog = petMap.get("My Dog");
20         System.out.println(dog);
21         System.out.println(petMap.containsKey("My Dog"));
22         System.out.println(petMap.containsValue(dog));
23         
24     }
25 
26 }

import java.util.*;

/** 
 * @author zlz099: 
 * @version 创建时间：2017年9月28日 上午11:10:56 
 */
public class PrintContainers {
    static Collection fill(Collection<String> collection){
        collection.add("rat");
        collection.add("cat");
        collection.add("dog");
        collection.add("dog");
        return collection;
    }
    static Map fill(Map<String, String> map){
        map.put("rat", "Fuzzy");
        map.put("cat", "Rags");
        map.put("dog", "Bosco");
        map.put("dog", "Spot");
        return map;
    }
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        System.out.println(fill(new ArrayList<String>()));
        System.out.println(fill(new LinkedList<String>()));
        System.out.println(fill(new HashSet<String>()));
        System.out.println(fill(new TreeSet<String>()));
        System.out.println(fill(new LinkedHashSet<String>()));
        System.out.println(fill(new HashMap<String,String>()));
        System.out.println(fill(new TreeMap<String,String>()));
        System.out.println(fill(new LinkedHashMap<String,String>()));
        
    }

}

import java.util.*;

/** 
 * @author zlz099: 
 * @version 创建时间：2017年9月28日 上午11:10:56 
 */
public class PrintContainers {
    static Collection fill(Collection<String> collection){
        collection.add("rat");
        collection.add("cat");
        collection.add("dog");
        collection.add("dog");
        return collection;
    }
    static Map fill(Map<String, String> map){
        map.put("rat", "Fuzzy");
        map.put("cat", "Rags");
        map.put("dog", "Bosco");
        map.put("dog", "Spot");
        return map;
    }
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        System.out.println(fill(new ArrayList<String>()));
        System.out.println(fill(new LinkedList<String>()));
        System.out.println(fill(new HashSet<String>()));
        System.out.println(fill(new TreeSet<String>()));
        System.out.println(fill(new LinkedHashSet<String>()));
        System.out.println(fill(new HashMap<String,String>()));
        System.out.println(fill(new TreeMap<String,String>()));
        System.out.println(fill(new LinkedHashMap<String,String>()));
        
    }

}

 1 import java.util.ArrayList;
 2 import java.util.Arrays;
 3 import java.util.Collections;
 4 import java.util.HashSet;
 5 import java.util.List;
 6 import java.util.PriorityQueue;
 7 import java.util.Random;
 8 import java.util.Set;
 9 
10 /** 
11  * @author zlz099: 
12  * @version 创建时间：2017年10月11日 下午3:17:29 
13  */
14 public class PriorityQueueDemo {
15 
16     public static void main(String[] args) {
17         // TODO Auto-generated method stub
18         PriorityQueue<Integer> priorityQueue = new PriorityQueue<Integer>();
19         Random rand = new Random(47);
20         for(int i = 0; i < 10; i++)
21             priorityQueue.offer(rand.nextInt(i+10));
22         QueueDemo.printQ(priorityQueue);
23         List<Integer> ints = Arrays.asList(25,22,20,18,14,9,3,1,1,2,3,9,14,18,21,23,25);
24         priorityQueue = new PriorityQueue<Integer>(ints);
25         QueueDemo.printQ(priorityQueue);
26         priorityQueue = new PriorityQueue<Integer>(ints.size(),Collections.reverseOrder());
27         priorityQueue.addAll(ints);
28         QueueDemo.printQ(priorityQueue);
29         
30         String fact = "EDUCATION SHOULD ESCHEW OBFUSCATION";
31         List<String> strings = Arrays.asList(fact.split(""));
32         PriorityQueue<String> stringPQ = new PriorityQueue<String>(strings);
33         QueueDemo.printQ(stringPQ);
34         stringPQ = new PriorityQueue<String>(strings.size(),Collections.reverseOrder());
35         stringPQ.addAll(strings);
36         QueueDemo.printQ(stringPQ);
37         
38         Set<Character> charSet = new HashSet<Character>();
39         for(char c : fact.toCharArray())
40             charSet.add(c);
41         PriorityQueue<Character> characterPQ = new PriorityQueue<Character>(charSet);
42         QueueDemo.printQ(characterPQ);
43     }
44 
45 }

 1 import java.util.LinkedList;
 2 import java.util.Queue;
 3 import java.util.Random;
 4 
 5 /** 
 6  * @author zlz099: 
 7  * @version 创建时间：2017年10月11日 下午3:03:28 
 8  */
 9 public class QueueDemo {
10     public static void printQ(Queue queue){
11         while(queue.peek()!=null)
12             System.out.print(queue.remove()+" ");
13         System.out.println();
14     }
15     public static void main(String[] args) {
16         // TODO Auto-generated method stub
17         Queue<Integer> queue = new LinkedList<Integer>();
18         Random rand = new Random(47);
19         for(int i = 0; i < 10;i++)
20             queue.offer(rand.nextInt(i+10));
21         printQ(queue);
22         Queue<Character> qc = new LinkedList<Character>();
23         for(char c :"Brontosaurus".toCharArray())
24             qc.offer(c);
25         printQ(qc);
26     }
27 
28 }

 1 import java.util.LinkedList;
 2 import java.util.Queue;
 3 import java.util.Random;
 4 
 5 /** 
 6  * @author zlz099: 
 7  * @version 创建时间：2017年10月11日 下午3:03:28 
 8  */
 9 public class QueueDemo {
10     public static void printQ(Queue queue){
11         while(queue.peek()!=null)
12             System.out.print(queue.remove()+" ");
13         System.out.println();
14     }
15     public static void main(String[] args) {
16         // TODO Auto-generated method stub
17         Queue<Integer> queue = new LinkedList<Integer>();
18         Random rand = new Random(47);
19         for(int i = 0; i < 10;i++)
20             queue.offer(rand.nextInt(i+10));
21         printQ(queue);
22         Queue<Character> qc = new LinkedList<Character>();
23         for(char c :"Brontosaurus".toCharArray())
24             qc.offer(c);
25         printQ(qc);
26     }
27 
28 }

 1 import java.util.*;
 2 
 3 /** 
 4  * @author zlz099: 
 5  * @version 创建时间：2017年10月11日 上午10:01:20 
 6  */
 7 public class SetOfInteger {
 8 
 9     public static void main(String[] args) {
10         // TODO Auto-generated method stub
11         Random rand = new Random(47);
12         Set<Integer> intset = new HashSet<Integer>();
13         for(int i = 0 ;i < 10000;i++)
14             intset.add(rand.nextInt(10));
15         System.out.println(intset);
16     }
17 
18 }

 1 /** 
 2  * @author zlz099: 
 3  * @version 创建时间：2017年10月11日 上午10:32:51 
 4  */
 5 import java.util.*;
 6 public class SetOperation {
 7 
 8     public static void main(String[] args) {
 9         // TODO Auto-generated method stub
10         Set<String> set1 = new HashSet<String>();
11         Collections.addAll(set1, "A B C D E F G H I J K L".split(" "));
12         set1.add("M");
13         System.out.println("H: "+set1.contains("H"));
14         System.out.println("N: "+set1.contains("N"));
15         Set<String> set2 = new HashSet<String>();
16         Collections.addAll(set2, "H I J K L".split(" "));
17         System.out.println("set2 in set1: "+set1.containsAll(set2));
18         set1.remove("H");
19         System.out.println("Set1: "+set1);
20         System.out.println("set2 in set1: "+set1.containsAll(set2));
21         set1.removeAll(set2);
22         System.out.println("set2 removed from set1: "+set1);
23         Collections.addAll(set1, "X Y Z".split(" "));
24         System.out.println(" ‘X Y Z‘ added to set1: "+set1);
25     }
26 }

 1 import java.util.ArrayList;
 2 import java.util.Collection;
 3 
 4 /** 
 5  * @author zlz099: 
 6  * @version 创建时间：2017年9月28日 上午10:28:20 
 7  */
 8 public class SimpleCollection {
 9 
10     public static void main(String[] args) {
11         // TODO Auto-generated method stub
12         Collection<Integer> c = new ArrayList<Integer>();
13         for(int i = 0; i < 10; i++)
14             c.add(i);
15         for(Integer i : c)
16             System.out.print(i+", ");
17             
18     }
19 
20 }

 1 /** 
 2  * @author zlz099: 
 3  * @version 创建时间：2017年10月9日 上午11:14:58 
 4  */
 5 import java.util.Iterator;
 6 import java.util.List;
 7 
 8 import pets.*;
 9 
10 public class SimpleIteration {
11 
12     public static void main(String[] args) {
13         // TODO Auto-generated method stub
14         List<Pet> pets = Pets.arrayList(12);
15         Iterator<Pet> it = pets.iterator();
16         while(it.hasNext()){
17             Pet p = it.next();
18             System.out.print(p.id()+":"+p+" ");
19         }
20         System.out.println();
21         for(Pet p : pets){
22             System.out.print(p.id()+":"+p+" ");
23         }
24         System.out.println();
25         it = pets.iterator();
26         for(int i = 0; i<6;i++){
27             it.next();
28             it.remove();
29         }
30         System.out.print(pets);
31         
32     }
33     
34 
35 }

 1 import java.util.Random;
 2 import java.util.SortedSet;
 3 import java.util.TreeSet;
 4 
 5 /** 
 6  * @author zlz099: 
 7  * @version 创建时间：2017年10月11日 上午10:27:46 
 8  */
 9 public class SortedSetOfInteger {
10 
11     public static void main(String[] args) {
12         // TODO Auto-generated method stub
13         Random rand = new Random(47);
14         SortedSet<Integer> intset = new TreeSet<Integer>();
15         for(int i = 0; i < 1000 ; i++)
16             intset.add(rand.nextInt(30));
17         System.out.println(intset);
18     }
19 
20 }

 1 import java.util.HashMap;
 2 import java.util.Map;
 3 import java.util.Random;
 4 
 5 /** 
 6  * @author zlz099: 
 7  * @version 创建时间：2017年10月11日 上午10:59:46 
 8  */
 9 public class Statistics {
10 
11     public static void main(String[] args) {
12         // TODO Auto-generated method stub
13         Random rand = new Random(47);
14         Map<Integer, Integer> m = new HashMap<Integer,Integer>();
15         for(int i = 0; i < 10000;i++){
16             int r = rand.nextInt(20);
17             Integer freq = m.get(r);
18             m.put(r, freq == null ? 1 : freq+1);
19         }
20         System.out.println(m);
21     }
22 }

 1 package stacktest;
 2 
 3 import java.util.LinkedList;
 4 
 5 /** 
 6  * @author zlz099: 
 7  * @version 创建时间：2017年10月9日 下午9:59:42 
 8  */
 9 public class Stack<T> {
10     private LinkedList<T> storage = new LinkedList<T>();
11     public void push(T v){storage.addFirst(v);}
12     public T peek(){return storage.getFirst();}
13     public T pop(){return storage.removeFirst();}
14     public boolean empty(){return storage.isEmpty();}
15     public String toString(){return storage.toString();}
16 }

 1 package stacktest;
 2 /** 
 3  * @author zlz099: 
 4  * @version 创建时间：2017年10月11日 上午9:45:44 
 5  */
 6 public class StackCollection {
 7 
 8     public static void main(String[] args) {
 9         // TODO Auto-generated method stub
10         stacktest.Stack<String> stack = new stacktest.Stack<String>();
11         for(String s : "My dog has fleas".split(" "))
12             stack.push(s);
13         while(!stack.empty())
14             System.out.print(stack.pop()+" ");
15         System.out.println();
16         java.util.Stack<String> stack2 = new java.util.Stack<String>();
17         for(String s :"My dog has fleas".split(" "))
18             stack2.push(s);
19         while(!stack2.empty())
20             System.out.print(stack2.pop()+" ");
21     }
22 
23 }

 1 package stacktest;
 2 /** 
 3  * @author zlz099: 
 4  * @version 创建时间：2017年10月9日 下午10:05:42 
 5  */
 6 public class StackTest {
 7 
 8     public static void main(String[] args) {
 9         // TODO Auto-generated method stub
10         Stack<String> stack = new Stack<String>();
11         for(String s : "My dogs has fleas".split(" "))
12             stack.push(s);
13         while(!stack.empty())
14             System.out.print(stack.pop()+" ");
15     }
16 }