/*
* 1. 假如有以下email數據“[email protected],[email protected],[email protected],..”
* 現需要把email中的用戶部分和郵件地址部分分離,分離後以鍵值對應的方式放入HashMap
*/
package first;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;
public class Test {
public static void main(String[] args){
String []str={"[email protected]","[email protected]", "[email protected]"};
//創建一個hashmap的對象,用於接收數據
Map<String,String> hmMap=new HashMap<String,String>();
for(int i=0;i<str.length;i++){
//取出單個的郵箱
String mail=str[i];
String username=mail.substring(0,mail.indexOf('@'));
String emailAdd=mail.substring(3 );
hmMap.put(username,emailAdd);
}
//從hashmap中取數據
//因爲Map中沒有iterator,所以需要先把Map集合轉換成Set集合,使用keySet()方法
Set<String> set=hmMap.keySet();
Iterator<String> it=set.iterator();
while(it.hasNext()){
String key=(String)it.next();
String value=(String)hmMap.get(key);
System.out.println(key + "=" + value);
}
}
}
/*
* 2. 產生一組班級對象,並放入集合ArrayList對象中
*/package Second;
public class Class {
<span style="white-space:pre"> </span> private int id;
<span style="white-space:pre"> </span> private String name;
<span style="white-space:pre"> </span> Class(int id,String name){
<span style="white-space:pre"> </span> this.id=id;
<span style="white-space:pre"> </span> this.name=name;
<span style="white-space:pre"> </span>
<span style="white-space:pre"> </span> }
<span style="white-space:pre"> </span>public int getId() {
<span style="white-space:pre"> </span>return id;
<span style="white-space:pre"> </span>}
<span style="white-space:pre"> </span>public void setId(int id) {
<span style="white-space:pre"> </span>this.id = id;
<span style="white-space:pre"> </span>}
<span style="white-space:pre"> </span>public String getName() {
<span style="white-space:pre"> </span>return name;
<span style="white-space:pre"> </span>}
<span style="white-space:pre"> </span>public void setName(String name) {
<span style="white-space:pre"> </span>this.name = name;
<span style="white-space:pre"> </span>}
<span style="white-space:pre"> </span>
}
package Second;
import java.util.ArrayList;
public class Test {
public static void main(String[] args) {
ArrayList<Class> list=new ArrayList<Class>();
Class class1=new Class(100000,"計124-1");
Class class2=new Class(100002,"計124-1");
Class class3=new Class(100003,"計124-1");
Class class4=new Class(100004,"計124-1");
//向list集合中插入數據
list.add(class1);
list.add(class2);
list.add(class3);
list.add(class4);
//從list中取數據
for(Class str:list){
System.out.print("班號:"+str.getId()+" ");
System.out.println("班名:"+str.getName());
}
}
}
/*
* 3.編寫類,將客戶的地址信息封裝到Customer對象中,對象包括姓名、街道、市(縣)、省(自治區)
* 、和國家(地區)等字段信息,將客戶信息存放到Vector中。結果如圖:(注意換行)
*
*/
package third;
public class Customer{
private String cusName;
private String cusCountry;
private String cusProvince;
private String cusCity;
private String cusroad;
Customer(String name,String country,String province, String city,String road){
this.cusName=name;
this.cusCountry=country;
this.cusProvince=province;
this.cusCity=city;
this.cusroad=road;
}
public String getCusName() {
return cusName;
}
public void setCusName(String cusName) {
this.cusName = cusName;
}
public String getCusCountry() {
return cusCountry;
}
public void setCusCountry(String cusCountry) {
this.cusCountry = cusCountry;
}
public String getCusProvince() {
return cusProvince;
}
public void setCusProvince(String cusProvince) {
this.cusProvince = cusProvince;
}
public String getCusCity() {
return cusCity;
}
public void setCusCity(String cusCity) {
this.cusCity = cusCity;
}
public String getCusroad() {
return cusroad;
}
public void setCusroad(String cusroad) {
this.cusroad = cusroad;
}
}
package third;
import java.util.Vector;
public class Test {
/**
* @param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
Vector<Customer> vector=new Vector<Customer>();
Customer customer1=new Customer("張三","中國","北京","北京","王府井");
Customer customer2=new Customer("李四","中國","山東","青島","福田路");
Customer customer3=new Customer("王二麻子","USA","II","PP","PP");
vector.add(customer1);
vector.add(customer2);
vector.add(customer3);
for(Customer cus:vector){
System.out.println("姓名:"+cus.getCusName());
System.out.println("國家:"+cus.getCusCountry());
System.out.println("省(自治區):"+cus.getCusProvince());
System.out.println("市(縣):"+cus.getCusCity());
System.out.println("街道:"+cus.getCusroad());
System.out.println();
System.out.println();
}
}
}
/*
* 4..編寫類,該類有方法接收一些字符串(apple,graps,organge,lemon,pineapple),並將這些值存儲在ArrayList中。倒序顯示ArrayList中的內容。
*/
package fourth;
import java.lang.reflect.Array;
import java.util.ArrayList;
import java.util.List;
public class ArrayList1 {
/*
編寫類,該類有方法接收一些字符串(apple,graps,organge,lemon,pineapple),並將這些值存儲在ArrayList中。倒序顯示ArrayList中的內容。
*/
public static List<String> accept(String []str){
ArrayList<String > arraylist=new ArrayList<String >();
System.out.println("正序輸出該字符串:");
for(int i=0;i<str.length;i++){
arraylist.add(str[i]);
System.out.print(arraylist.get(i)+" ");
}
System.out.print("\n");
return arraylist;
}
public static void showList(List<String> arraylist){
System.out.println("倒序輸出該字符串:");
int num=arraylist.size();
for(int i=num-1;i>=0;i--){
System.out.print(arraylist.get(i)+" ");
}
}
public static void main(String[] args) {
// TODO Auto-generated method stub
String []str={"apple","graps","organge","lemon","pineapple"};
showList(accept(str));
}
}
/*
* 5. 定義學生信息實體類student,包含學生的姓名和成績倆個字段。將該實體存入泛型HashMap<String,Student>。
* 學員的姓名和他們的分數:張三,90分;李四,88分。然後從HashMap對象中獲取者倆個人的成績並顯示出來,接着
* 把張三的成績改爲99分再把它們的成績顯示出來。
*/
package fiveth;
public class Student {
private String sname;
private double sscore;
private int id;
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public Student(String sname, double sscore) {
super();
this.sname = sname;
this.sscore = sscore;
}
public String getSname() {
return sname;
}
public void setSname(String sname) {
this.sname = sname;
}
public double getSscore() {
return sscore;
}
public void setSscore(double sscore) {
this.sscore = sscore;
}
}
package fiveth;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;
public class TestClass {
public static void display(HashMap<String, Student> stuMap) {
/*for (Entry<String, Student> entry : stuMap.entrySet()) {
System.out.println(entry.getKey() + " 的成績爲:"
+ entry.getValue().getSscore());
}
*/
Set <String> set=stuMap.keySet();
Iterator it=set.iterator();
while(it.hasNext()){
String key=(String)it.next();
Student value=stuMap.get(key);
System.out.println(key+"的成績是 "+value.getSscore());
}
}
public static void main(String[] args) {
HashMap<String, Student> stuMap= new HashMap<String, Student>();
Student stu2 = new Student("張三", 90);
Student stu1 = new Student("李四", 88);
stuMap.put(stu1.getSname(), stu1);
stuMap.put(stu2.getSname(), stu2);
display(stuMap);
System.out.println("==========================");
stuMap.remove(stu1);
stu1.setSscore(99);
stuMap.put(stu1.getSname(), stu1);
display(stuMap);
}
}