Java学习第十五天（小总结）
一、今天干了什么
完成了客户信息管理系统！虽然磕磕绊绊，断断续续做了好几天，中途思路经常受阻，还得回头看尚硅谷的教学视频，不过做完之后成就感爆棚。
（测试截图太多，不往上放了）
分成了四个包，每个包里有一个类，通过import关键字来让这几个类相互关联、相互调用。
Customer类用于存储用户信息；CustomerList类是对象管理模块，提供检验增加客户、修改指定客户信息、删除指定客户信息、查看所有客户信息、获取存储的客户数量是否成功的布尔类型方法以便CustomerView类调用；CustomerView负责菜单的显示和客户操作方面的方法，并且主方法放在这里；CMUtitlity类是工具类（难度较大，没有自己写，直接从网上扒的尚硅谷老师的代码）。
代码如下：
Customer类：
package pers.yan.PersonInformation; public class Customer { private String name; private char sex; private int age; private String phone; private String email; public Customer() { } public Customer(String name,char sex,int age,String phone,String email) { this.age = age; this.name = name; this.sex = sex; this.phone = phone; this.email = email; } public void setAge(int age) { this.age = age; } public int getAge() { return age; } public void setName(String name) { this.name = name; } public String getName() { return name; } public void setSex(char sex) { this.sex = sex; } public char getSex() { return sex; } public void setPhone(String phone) { this.phone = phone; } public String getPhone() { return phone; } public void setEmail(String email) { this.email = email; } public String getEmail() { return email; } }
CustomerList类:
package pers.yan.service; import pers.yan.PersonInformation.Customer; public class CustomerList { private Customer[] customers; private int total = 0; //已保存客户对象的数量 public CustomerList(int num) //构造器 { customers = new Customer[num]; } public boolean addCustomer(Customer customer) //添加用户 { if(total >= customers.length) { return false; } customers[total] = customer; total++; return true; } public boolean replaceCustomer(int index, Customer cust) //修改用户信息 { if(index < 0 || index >= total) { return false; } customers[index] = cust; return true; } public boolean deleteCustomer(int index) //删除用户信息 { if(index < 0 || index >= total) { return false; } for(int i = index;i < total -1;i++) { customers[i]=customers[i+1]; } customers[total - 1] = null; total--; return true; } public Customer[] getAllCustomers() { Customer[] custs = new Customer[total]; for(int i = 0;i < total;i++) { custs[i] = customers[i]; } return custs; } public Customer getCustomer(int index) { if(index < 0 || index >= total) { return null; } return customers[index]; } public int getTotal() //获取存储的客户数量 { return total; } }
CustomerView类：
package pers.yan.ui; import pers.yan.PersonInformation.*; import pers.yan.service.CustomerList; import pers.yan.util.*; public class CustomerView { private CustomerList customerList = new CustomerList(10); public CustomerView() { Customer customer = new Customer("闫世豪",'男',19,"13242314256","3332831867@qq.com"); customerList.addCustomer(customer); } public void enterMainMenu() //显示《客户信息管理系统》页面 { boolean isFlag = true; while(isFlag) { System.out.println("\n---------------------客户信息管理软件-----------------------"); System.out.println(" 1.添加客户"); System.out.println(" 2.修改客户"); System.out.println(" 3.删除客户"); System.out.println(" 4.客户列表"); System.out.println(" 5.退出"); System.out.println(" 请选择（1-5）："); char menu = CMUtitlity.readMenuSelection(); switch(menu) { case '1': addNewCustomer(); break; case '2': modifyCustomer(); break; case '3': deleteCustomer(); break; case '4': listAllCustomers(); break; case '5': System.out.print("确认是否退出（Y/N）"); char isExit = CMUtitlity.readConfirm(); if(isExit == 'Y') { isFlag = false; } break; } } } private void addNewCustomer() //添加客户 { System.out.println("添加客户的操作"); System.out.println("------------------------------添加客户----------------------------"); System.out.println("姓名："); String name = CMUtitlity.readString(10,null); System.out.println("性别："); char gender = CMUtitlity.readChar('0'); System.out.println("年龄："); int age = CMUtitlity.readInteger(0); System.out.println("电话："); String phone = CMUtitlity.readString(13, null); System.out.println("邮箱："); String email = CMUtitlity.readString(30, null); Customer newone = new Customer(name,gender,age,phone,email);//封装进入一个新的对象 boolean isSuccess = customerList.addCustomer(newone); if(isSuccess) { System.out.println("----------------------------添加完成-----------------------------"); } else { System.out.println("----------------------------客户目录已满，添加失败---------------------------"); } } private void modifyCustomer() //修改客户信息 { System.out.println("修改客户信息的操作"); System.out.println("----------------------------修改客户-----------------------------"); int number; Customer dust; for(;;) { System.out.println("请选择待修改客户的编号（-1退出）："); number = CMUtitlity.readInteger(0); if(number == -1) { return; } dust = customerList.getCustomer(number - 1); if(dust == null) { System.out.println("无法找到指定客户！"); } else //找到了对应客户 { break; } } //修改客户信息 System.out.println("姓名(" + dust.getName() + ")"); String name = CMUtitlity.readString(10,dust.getName()); System.out.println("性别(" + dust.getSex() + ")"); char sex = CMUtitlity.readChar(dust.getSex()); System.out.println("年龄(" + dust.getAge() + ")"); int age = CMUtitlity.readInteger(dust.getAge()); System.out.println("电话(" + dust.getPhone() + ")"); String phone = CMUtitlity.readString(13,dust.getPhone()); System.out.println("邮箱(" + dust.getEmail() + ")"); String email = CMUtitlity.readString(30,dust.getEmail()); Customer newCust = new Customer(name,sex,age,phone,email); boolean isReplaced = customerList.replaceCustomer(number - 1,newCust); if(isReplaced) { System.out.println("-------------------------------修改完成-------------------------------"); } else { System.out.println("-------------------------------修改失败-------------------------------"); } } private void deleteCustomer() { System.out.println("删除客户的操作"); System.out.println("------------------------------------删除客户---------------------------------"); int num; for(;;) { System.out.println("请选择删除客户编号（-1退出）："); num = CMUtitlity.readInteger(0); if(num == -1) { return ; } Customer customer = customerList.getCustomer(num - 1); if(customer == null) { System.out.println("无法找到指定客户！"); } else { break; } } //找到了指定客户 System.out.print("确认是否删除（Y/N)"); char isDelete = CMUtitlity.readConfirm(); if(isDelete == 'Y') { boolean deleteSuccess = customerList.deleteCustomer(num -1); if(deleteSuccess) { System.out.println("-------------------------------删除完成-------------------------------"); } else { System.out.println("-------------------------------删除失败-------------------------------"); } } else { return; } } private void listAllCustomers() { //System.out.println("显示客户列表的操作"); System.out.println("------------------------------客户列表----------------------------"); int total = customerList.getTotal(); if(total == 0) { System.out.println("没有客户记录"); } else { System.out.println("编号\t姓名\t性别\t年龄\t电话\t\t邮箱"); Customer[] custs = customerList.getAllCustomers(); for(int i = 0;i < total;i++) { Customer cust = custs[i]; System.out.println((i+1) + "\t" + cust.getName() +"\t" + cust.getSex() + "\t" + cust.getAge() +"\t" + cust.getPhone() + "\t" + cust.getEmail()); } } System.out.println("-----------------------------客户列表完成----------------------------"); } public static void main(String[] args) { CustomerView view = new CustomerView(); view.enterMainMenu(); } }
CMUtitlity类：
package pers.yan.util; import java.util.*; public class CMUtitlity { /** * 将不同的方法封装到工具类，外部直接调用无需考虑具体实现 */ private static Scanner scanner = new Scanner(System.in); /** * 读取长度不超过limit长度的用户输入，用户回车后返回字符串 */ public static String readKeyBoard(int limit,boolean blankReturn){ String line = ""; while(scanner.hasNextLine()){ line = scanner.nextLine(); if(line.length() == 0){ if(blankReturn){ return line; }else continue; } if(line.length() < 1 || line.length() > limit ){ System.out.println("请输入字符串长度应不大于" + limit + "，请重新输入"); continue; } break; } return line; } /** * 获取用户输入1-5的字符：如果用户输入1-5的字符，则返回用户输入值 */ public static char readMenuSelection(){ char c; for (;;){ String str = readKeyBoard(1,true); c = str.charAt(0); if(c != '1' && c != '2' && c != '3' && c != '4' && c != '5'){ System.out.println("选择错误，请重新输入"); }else break; } return c; } /** * 获取一个字符：获取用户输入的一个字符，若未输入则直接返回默认值 */ public static char readChar(char defaultValue){ String str = readKeyBoard(1,true); return (str.length() == 0)?defaultValue:str.charAt(0); } /** *获取长度小于2的整数，返若未输入则返回默认值 */ public static int readInteger(int defaultValue){ int n; for (;;){ String str = readKeyBoard(2,false); if(str.equals("")){ return defaultValue; } try{ n = Integer.parseInt(str); break; }catch (NumberFormatException e){ System.out.println("输入错误，请输入2位整数"); } } return n; } /** * 指定长度范围，获取用户输入的字符串，并返回;用户不输入则返回默认值 */ public static String readString(int limit,String defaultValue){ String str = readKeyBoard(limit,true); return str.equals("")?defaultValue:str; } /** * 用于确认选择的输入，从键盘中读取‘Y’ ‘N’,并返回 */ public static char readConfirm() { char c; for(;;){ String str = readKeyBoard(1,true).toUpperCase(); c = str.charAt(0); if(c == 'Y' || c == 'N'){ break; }else { System.out.println("选择错误，请重新输入"); } } return c; } }
一定要注意：
面向对象！封装！
二、明天要干什么
进入对继承性的学习
三、近几天遇到的问题：
1.构思不够明确导致后边写代码的时候很乱，不知道该怎么用；
2.自己写的时候被CustomerView类中如何判断是否增删改查成功弄的焦头烂额，在以后一定要加强对Customer类中boolean类型方法的使用，真的非常非常nice；
3.增删改客户信息的时候，一定要注意数组下标的问题，总是在这个地方出错；
4.定义多个构造器！
5.给一个构造器初始化以便边写边测试，同时，一定要记住每写一个方法（或者相关联的几个方法）都要进行一个小的测试，及时发现问题并修改；
6.新增用户信息或更改完用户信息之后记得将信息封装进入对象；
7.一定一定要注意编号的关系！！与第三点相通，如以下这两个CustomerList中的方法，非常重要！
