Java基础---集合框架---迭代器、ListIterator、Vector中枚举、LinkedList、ArrayList、HashSet、TreeSet、二叉树、Comparator

class LinkedListDemo{
public static void main(){
Linked link=new LinkedList();
link.addList("java01");
link.addlist("java02");

while(!link.isEmpty()){
sop(link.removeLast());
}

}
public static void sop(Object object){
System.out.println("obj");
}

}

class Queue{
private LinkedList link;
Queue{
link=new LinkedList();
}
public void myadd(Object obj){
link.addFirst(obj);
}
public Object myGet(){
return link.removeLast();
}
public boolean isNull(){
return link.isEmpty();
}

}

classArraylistTest{
public static void  main(){
ArrayList a1=new ArrayList();
a1.add("java01");
a1.add("java01");
a1.add("java01");
a1.add("java01");
a1.add("java01");

sop(a1);
a1=singleElement(a1);
sop(a1);
}

public static ArrayList singleElement(ArrayList al){
ArrayList newAl=new ArrayList();
Iterator it=al.iterator();
while(it.hasNext()){
Object obj=it.next();
if(newAl.contains(obj)){
newAl.add(obj);
}

}
return newAl;

}
public static void sop(Object object){
System.out.println("obj");
}

}

class Person{
private String name;
private int age;
Person(String name,int age)
{
this.name=name;
this.age=age;
}
public boolean equals(Object object){
if(!obj instanceof Person)
return false;
Person p=(Person)Obj;
return this.name.equals(p.name)&&this.age=p.age;

}

public String getName(){
return name;
}
public int getAge(){
return age;
}

}

Class ArrayListTest2{
public static void main(String[] args){
ArrayList a1=new ArrayList();
a1.add(new Person("lisi01,30"));

Iterator it=al.iterator();
while(it.hasNext()){
//想用特有方法时，就要转型，因为迭代器不知道你是什么类型，只返回obj
Object obj=it.next();
Person p=(Person) obj;
sop(it.next().getName()+"::"+it.next().getAge());
}

}

public static ArrayList singleElement(ArrayList al){
ArrayList newAl=new ArrayList();
Iterator it=al.iterator();
while(it.hasNext()){
Object obj=it.next();
if(newAl.contains(obj)){
newAl.add(obj);
}

}
return newAl;

}
}

class HashSetDemo
{
public static void sop(Object obj)
{
System.out.println(obj);
}
public static void main(String[] args)
{

HashSet hs = new HashSet();

sop(hs.add("java01"));
sop(hs.add("java01"));
hs.add("java02");
hs.add("java03");
hs.add("java03");
hs.add("java04");

Iterator it = hs.iterator();

while(it.hasNext())
{
sop(it.next());
}
}
}

import java.util.*;

/*
往hashSet集合中存入自定对象
姓名和年龄相同为同一个人，重复元素。
*/
class HashSetTest
{
public static void sop(Object obj)
{
System.out.println(obj);
}
public static void main(String[] args)
{
HashSet hs = new HashSet();

hs.add(new Person("a1",11));
hs.add(new Person("a2",12));
hs.add(new Person("a3",13));
//		hs.add(new Person("a2",12));
//		hs.add(new Person("a4",14));

//sop("a1:"+hs.contains(new Person("a2",12)));

//		hs.remove(new Person("a4",13));

Iterator it = hs.iterator();

while(it.hasNext())
{
Person p = (Person)it.next();
sop(p.getName()+"::"+p.getAge());
}
}
}

class Person
{
private String name;
private int age;
Person(String name,int age)
{
this.name = name;
this.age = age;
}

public int hashCode()
{
System.out.println(this.name+"....hashCode");
return name.hashCode()+age*37;//这个地方37，只是在一个范围里面。与具体的值无关
}

public boolean equals(Object obj)//这个地方记复写，
{

if(!(obj instanceof Person))
return false;

Person p = (Person)obj;
System.out.println(this.name+"...equals.."+p.name);

return this.name.equals(p.name) && this.age == p.age;
}

public String getName()
{
return name;
}
public int getAge()
{
return age;
}
}

Class TreeSetDemo(){
public static void main(){
TreeSet ts=new TreeSet();
ts.add(new Student("liuhan",22));
ts.add(new Student("diudan",24));//这个学生对象不具有比较性//找一个接口去实现它，实现了就具有比较性
Iterator it=ts.Iterator();
while(it.hasNext()){
System.out.println(it.next());
}
}
}

Class Student implements Comparable{//该接口强制学生具有比较性
private String name;
private int age;
Student (String name,int age){
this.name=name;
this.age=age;
}
public int CompareTo(){
if(!(obj instanceof Student))
throw new RuntimeException("不是学生对象");
Student s=(Student)Obj;
System.out.println(this.name+"...Compare to"+s.name);
if(this.age>s.age)//此对象与参数对象进行比较
return 1;
if(this.age==s.age)
{
this.name.compareTo(s.name);//如果年龄相同，就按照字符串排序
}
//当主要条件相同时，就按次要条件排序。
return 0;
return -1;
}
public String getName(){
return name;
}
public String getAge(){
return age;
}
}

class MyCompare implements Comparator{
public int compare(Object o1,Object o2){
Student s1=(Student)o1;
Student s2=(Student)o2;

int num=s1.getName().compareTo(s2.getName());
if(num==0){
return s1.getAge()-s2.getAge();
//对象封装，调用CompareTo
return new Integar(s1.getAge()).compareTo(new Integer(s2.getAge()));
}

return num;
}
}

import java.util.*;
class  TreeSetTest
{
public static void main(String[] args)
{
TreeSet ts = new TreeSet(new StrLenComparator());

ts.add("abcd");
ts.add("cc");
ts.add("cba");
ts.add("aaa");
ts.add("z");
ts.add("hahaha");

Iterator it = ts.iterator();

while(it.hasNext())
{
System.out.println(it.next());
}
}
}

class StrLenComparator implements Comparator
{
public int compare(Object o1,Object o2)
{
String s1 = (String)o1;
String s2 = (String)o2;

/*
if(s1.length()>s2.length())
return 1;
if(s1.length()==s2.length())
return 0;
*/

int num = new Integer(s1.length()).compareTo(new Integer(s2.length()));
if(num==0)
return s1.compareTo(s2);

return num;
}
}