在java控制台中编写电话本，利用hashmap存储数据

来源：互联网发布：乐安全软件编辑：程序博客网时间：2024/04/29 08:20
这是java中的控制台的电话本小程序，使用了hashmap存储联系人信息

打印所有联系人
查找联系人
package com.dsr.java;import java.util.HashMap;import java.util.Iterator;import java.util.LinkedHashMap;import java.util.Scanner;public class phonebook {    boolean startsingle = true;    Scanner sc = new Scanner(System.in);    // LinkedHashMap是HashMap的一个子类，他会维护一个链表，记录你的插入循序，让你能够按顺序输出。    LinkedHashMap<String, books> book = new LinkedHashMap<String, books>();    private String name;    private String sex;    private String age;    private String num;    public static void main(String[] args) {        // TODO Auto-generated method stub        new phonebook().run();    }    private void run() {        // TODO Auto-generated method stub        while (startsingle) {            System.out.println("———————————————————电话本———————————————————");            System.out.println("1.添加\t2.删除\t3.修改\t4.查询\t5.打印全部\t0.退出");            System.out.println("———————————————————电话本———————————————————");            System.out.println("请输入数字选择功能");            String select = sc.next();            switch (select) {            case "1":                add();                break;            case "2":                delete();                break;            case "3":                update();                break;            case "4":                search();                break;            case "5":                printall();                break;            case "0":                sc.close();                startsingle = false;                break;            default:                System.out.println("输错了，重来！！！！");                break;            }        }    }    private void printall() {        // TODO Auto-generated method stub        // 1.常见的打印方式        int i = 1;        for (String key : book.keySet()) {            System.out.print("第" + i + "位联系人\t");            System.out.println(book.get(key).printone());            i++;        }        //Iterator iter=book.entrySet().iterator();        //while(iter.hasNext()){        //  System.out.println(iter.next());        //}    }    private void search() {        // TODO Auto-generated method stub        System.out.println("输入查询的联系人姓名");        name = sc.next();        if (find(name) == 0) {            System.out.println("联系人不存在！！！！");            return;        }        System.out.println(book.get(name).printone());    }    private void update() {        // TODO Auto-generated method stub        System.out.println("输入要修改的联系人信息！！！");        name = sc.next();        int update = find(name);        if (update == 0) {            System.out.println("你要修改的联系人不存在！！！！");            return;        }        book.remove(name);        books b = new books();        System.out.println("输入姓名！！！");        name = sc.next();        // 联系人信息修改之后会附带着修改hashmap中的键        b.setName(name);        System.out.println("输入性别！！！");        b.setSex(sc.next());        System.out.println("输入年龄！！！");        b.setAge(sc.next());        System.out.println("输入电话！！！");        b.setNum(sc.next());        book.put(name, b);        System.out.println(b.printone());        b = null;        System.gc();    }    private void delete() {        // TODO Auto-generated method stub        System.out.println("请输入要删除联系人的姓名！！！！！");        String name = sc.next();        int i = find(name);        if (i == 1) {            book.remove(name);            System.out.println("删除成功！！！！");        } else {            System.out.println("你要删除的联系人不存在！！！！");        }    }    private void add() {        // TODO Auto-generated method stub        name = null;        boolean addsingle = true;        while (addsingle) {            System.out.println("输入姓名！！！！！");            name = sc.next();            if (book.get(name) != null) {                System.out.println("联系人已存在，确认覆盖联系人？？？？？");                System.out.println("1.覆盖\t2.重新输入\t3.取消");                String covervalue = sc.next();                switch (covervalue) {                case "1":                    System.out.println("输入姓名！！！！！");                    name = sc.next();                    addsingle = false;                    break;                case "2":                    break;                case "3":                    addsingle = false;                    return;                default:                    System.out.println("输错了！！！！");                    break;                }            } else {                addsingle = false;            }        }        System.out.println("输入性别！！！！！");        sex = sc.next();        System.out.println("输入姓年龄！！！！！");        age = sc.next();        System.out.println("输入电话！！！！！");        num = sc.next();        books b = new books();        b.setName(name);        b.setAge(age);        b.setNum(num);        b.setSex(sex);        book.put(name, b);        System.out.println("添加成功");        System.out.println(b.printone());        b = null;        System.gc();    }    private int find(String name) {        if (book.get(name) == null) {            return 0;// 表示不存在        }        return 1;    }}class books {    private String name;    private String sex;    private String age;    private String num;    public String printone() {        return "name:" + name + "\tsex:" + sex + "\tage:" + age + "\tnum："                + num;    }    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 getNum() {        return num;    }    public void setNum(String num) {        this.num = num;    }}
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