使用Map集合写电话本程序

电话本管理系统 

  1.主界面

大体就是要实现对电话本的增删改查：

因为不清楚要存储的数据的数量，所以可以使用ArrayList不定长数组去实现，也可以使用集合类去做，此题我用Map集合来做。

废话不多说，直接上代码：

PhoneInfo类定义了一些属性，变量及构造方法

public class PhoneInfo {private String name;private String sex;private String age;private String tel;private String qq;private String address;public String getName() {return name;}public void setName(String name) {this.name = name;}public String getSex() {return sex;}public void setSex(String sex) {this.sex = sex;}public String getAge() {return age;}public void setAge(String age) {this.age = age;}public String getTel() {return tel;}public void setTel(String tel) {this.tel = tel;}public String getQq() {return qq;}public void setQq(String qq) {this.qq = qq;}public String getAddress() {return address;}public void setAddress(String address) {this.address = address;}public PhoneInfo(String name, String sex, String age, String tel, String qq, String address) {super();this.name = name;this.sex = sex;this.age = age;this.tel = tel;this.qq = qq;this.address = address;}@Overridepublic String toString() {return "PhoneInfo [name=" + name + ", sex=" + sex + ", age=" + age + ", tel=" + tel + ", qq=" + qq+ ", address=" + address + "]";}}

TelBook类封装了对电话本的操作：增删改查的方法。

import java.util.HashMap;import java.util.Iterator;import java.util.Map;import java.util.Scanner;import java.util.Set;public class TelBook {static Scanner sc = new Scanner(System.in);static TelBook tb = new TelBook();Map map = new HashMap<>();public static void main(String[] args) {System.out.println("————————————————————电话本管理系统——————————————————");System.out.println("1.添加       2.删除       3.修改       4.查询所有       5.根据姓名查询      0.退出");System.out.println("————————————————————电话本管理系统——————————————————");int option;do {System.out.println("请选择业务");option = sc.nextInt();switch (option) {case 1:tb.add();break;case 2:tb.delete();break;case 3:tb.modify();break;case 4:tb.find();break;case 5:tb.findName();break;case 0:System.out.println("电话本系统结束");break;default:}}while(option!=0);}public void add() {System.out.println("———————————添加电话本————————————");shuru();Set set = map.entrySet();Iterator it = set.iterator();while (it.hasNext()) {Map.Entry mapEntry = (Map.Entry) it.next();System.out.print(mapEntry.getKey() + "   " + mapEntry.getValue());}System.out.println();System.out.println("添加成功");}public void delete() {System.out.println("————————————删除电话本——————————————");System.out.println("请输入要删除的姓名");    String deleteName = sc.next();        if(map.containsValue(deleteName)) {        map.remove(deleteName);        System.out.println("删除成功");        }else         System.out.println("用户不存在！");}public void modify() {System.out.println("————————————修改电话本——————————————");System.out.println("请输入要修改的姓名");        String modifyName = sc.next();        if(map.containsValue(modifyName)) {        map.remove(modifyName);            shuru();             Set set = map.entrySet();Iterator it = set.iterator();while (it.hasNext()) {Map.Entry mapEntry = (Map.Entry) it.next();System.out.print(mapEntry.getKey() + "   " + mapEntry.getValue());}System.out.println();        }        else {        System.out.println("用户不存在");        }   }public void find() {System.out.println("——————————————查询所有——————————————");/* Set set = map.entrySet();Iterator it = set.iterator();while (it.hasNext()) {Map.Entry mapEntry = (Map.Entry) it.next();System.out.print(mapEntry.getKey() + "   " + mapEntry.getValue());}*/Set<String> set = map.keySet();for(String s:set) {System.out.println(map.get(s).toString());}}public void findName() {System.out.println("————————————根据姓名查询——————————————");System.out.println("请输入要查询的姓名");        String findName = sc.next();        if(map.containsValue(findName)) {          Set set = map.entrySet();Iterator it = set.iterator();while (it.hasNext()) {Map.Entry mapEntry = (Map.Entry) it.next();System.out.print(mapEntry.getKey() + "   " + mapEntry.getValue());}System.out.println();        }        else {        System.out.println("用户不存在");        }              }public void shuru() {PhoneInfo p = new PhoneInfo("", "", "", "", "", "");System.out.print("姓名：");String name = sc.next();p.setName(name);map.put("姓名：", name);System.out.println();System.out.print("性别：");String sex = sc.next();p.setSex(sex);map.put("性别：", sex);System.out.println();System.out.print("年龄：");String age = sc.next();p.setAge(age);map.put("年龄：", age);System.out.println();System.out.print("电话：");String tel = sc.next();p.setTel(tel);map.put("电话：", tel);System.out.println();System.out.print("QQ:");String qq = sc.next();p.setQq(qq);map.put("QQ：", qq);System.out.println();System.out.print("地址：");String address = sc.next();p.setAddress(address);map.put("地址：", address);System.out.println();}}

部分代码截图：

运行截图：

写在最后：从Map中获取元素一定要注意是Key值还是Value值，修改时要先remove.