用户管理系统
目录
用户管理系统
一、mycode.app包
下的UserApplication.java文件
二、mycode.dao包
package-info.java文件
IUserDao.java文件
UserDaoImpl.java文件
三、mycode.entity包
User.java文件
四、mycode.util包
ArrayList.java文件
DaoFactory.java文件
五、mycode.trst包
Test.java文件
六、data文件夹
users.data文件
项目包，文件布局
实现样式
一、mycode.app包
下的UserApplication.java文件
package mycode.app;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import mycode.dao.IUserDao;
import mycode.entity.User;
import mycode.util.DaoFactory;
public class UserApplication {
private static User user = null;
public static void main(String[] args) throws Exception {
IUserDao userDao = DaoFactory.getUserDao();
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
while (true) {
menu1();
String ss = br.readLine();
switch (ss) {
case "1":
User user = inputUser(br);
userDao.save(user);
break;
case "2":
User user1 = loginUser(br);
User bb = userDao.login(user1);
if (bb != null) {
UserApplication.user = bb;
System.out.println("登录成功!");
} else {
System.out.println("登录失败！请重新登录");
}
break;
case "3":
System.out.println("======目前已注册的用户列表======");
Object[] arr = userDao.getAll().toArray();
for (Object temp : arr) {
if (temp != null)
System.out.println(temp);
}
System.out.println("==============================");
break;
case "5":
UserApplication.user=null;
System.out.println("退出登录");
break;
case "4":
User user2 = mofidyUser(br);
userDao.update(user2);
UserApplication.user=null;
System.out.println("修改完毕！请重新登录");
break;
case "6":
System.out.println("输入要删除的用户编号:");
Long id=null;
while(true) {
String ss1=br.readLine();
try {
id=Long.parseLong(ss1);
break;
} catch (Exception e) {
System.out.println("输入的数据格式错误!请重新输入");
id=null;
}
}
if(id.equals(UserApplication.user.getId()))
UserApplication.user=null;
userDao.delete(id);
break;
}
if ("0".equals(ss)) {
System.out.println("bye~~bye");
break;
}
}
br.close();
}
private static User mofidyUser(BufferedReader br)throws Exception {
User res=UserApplication.user;
System.out.println("请输入新的用户名称和口令：");
System.out.println("原始名称为:"+res.getUsername());
System.out.println("请输入新用户名称：（不修改则直接回车）");
String username=br.readLine();
if(username!=null && username.trim().length()>=6 && username.trim().length()<=20)
res.setUsername(username);
System.out.println("请输入新用户口令：（不修改则直接回车）");
String password=br.readLine();
if(password!=null && password.trim().length()>=6 && password.trim().length()<=20)
res.setPassword(password);
return res;
}
private static User loginUser(BufferedReader br) {
System.out.println("请输入用户名称和口令：");
String username = inputString(br, "用户名称", 6, 20);
String password = inputString(br, "用户口令", 6, 20);
User user = new User();
user.setUsername(username);
user.setPassword(password);
return user;
}
public static void menu1() {
System.out.println("============欢迎使用本系统============");
System.out.println("1---新增用户 2---登录系统");
if (user != null) {
System.out.println("3---显示所有用户 4---修改注册信息");
System.out.println("5---退出登录 6---删除用户");
}
System.out.println("0---退出系统");
System.out.println("=====================================");
System.out.println("请选择...");
}
public static User inputUser(BufferedReader br) {
User user = new User();
String username = inputString(br, "用户名称", 6);
String password = null;
while (true) {
password = inputString(br, "用户口令", 6, 20);
String repassword = inputString(br, "确认口令");
if (password.equals(repassword))
break;
System.out.println("您输入的口令和确认口令不一致，请重新输入");
}
user.setUsername(username);
user.setPassword(password);
return user;
}
// int...如果有参数，则参数1为最小长度，参数2为最大长度
public static String inputString(BufferedReader br, String name, int... params) {
String res = null;
boolean flag = false;
System.out.println("请输入" + name + "：");
while (true) {
try {
res = br.readLine();
if (res != null && res.trim().length() > 0) {
if (params != null && params.length > 0) {
flag = res.trim().length() >= params[0];
if (flag) {
if (params.length > 1)
flag = res.trim().length() <= params[1];
}
} else
flag = true;
}
} catch (IOException e) {
e.printStackTrace();
}
if (flag)
break;
else
System.out.println("您输入的数据有误！请重新输入");
}
return res;
}
}二、mycode.dao包
package-info.java文件
package mycode.dao;
class Constants{
public static final String FILE_NAME="data/users.data";
public static final String TEMP_NAME="data/users_tmp.data";
}IUserDao.java文件
package mycode.dao;
import java.util.ArrayList;
import mycode.entity.User;
public interface IUserDao {//接口
//抽象方法
boolean save(User user);
User login(User user);
ArrayList getAll();
boolean update(User user);
boolean delete(Long id);
}UserDaoImpl.java文件
package mycode.dao;
import java.io.EOFException;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.util.ArrayList;
import mycode.entity.User;
import mycode.util.DaoFactory;
public class UserDaoImpl implements IUserDao {
@Override
public boolean save(User user) {
boolean res = false;
File oldFile = new File(Constants.FILE_NAME);
File tmpFile = new File(Constants.TEMP_NAME);
if (oldFile.exists()) {
try (ObjectInputStream ois = new ObjectInputStream(new FileInputStream(oldFile));
ObjectOutputStream oos = new ObjectOutputStream(new FileOutputStream(tmpFile));) {
long maxId = ois.readLong();
user.setId(maxId + 1);
oos.writeLong(user.getId());
while (true) {
try {
Object tmp = ois.readObject();
if (tmp != null)
oos.writeObject(tmp);
} catch (EOFException e) {
break;
}
}
oos.writeObject(user);
res = true;
} catch (Exception e) {
e.printStackTrace();
res = false;
}
} else {
try (ObjectOutputStream oos = new ObjectOutputStream(new FileOutputStream(oldFile));) {
user.setId(1L);
oos.writeLong(user.getId());
oos.writeObject(user);
} catch (Exception e) {
e.printStackTrace();
res=false;
}
}
if (oldFile.exists() && tmpFile.exists()) {
oldFile.delete();
tmpFile.renameTo(oldFile);
}
return res;
}
public static void main(String[] args) {
IUserDao userDao = DaoFactory.getUserDao();
// User user = new User();
// user.setUsername("lisi");
// user.setPassword("4444");
// boolean res=userDao.save(user);
// System.out.println(res?"成功":"失败");
// System.out.println(user.getId());
// User user=new User();
// user.setUsername("lisi");
// user.setPassword("5555");
// boolean bb=userDao.login(user);
// System.out.println(bb);
// ArrayList list = userDao.getAll();
// Object[] arr = list.getArray();
// for (Object temp : arr)
// if (temp != null)
// System.out.println(temp);
User user = new User();
user.setId(2L);
user.setUsername("lisi666");
user.setPassword("666666");
boolean res = userDao.update(user);
System.out.println(res ? "成功" : "失败");
}
@Override
public User login(User user) {
User res = null;
File oldFile = new File(Constants.FILE_NAME);
if (oldFile.exists()) {
try (ObjectInputStream ois = new ObjectInputStream(new FileInputStream(oldFile))) {
ois.skip(8);
while (true) {
Object obj = ois.readObject();
if (obj != null && obj instanceof User) {
User tmp = (User) obj;
if (user.equals(tmp)) {
res = tmp;
break;
}
}
}
} catch (EOFException e) {
System.out.println("文件结束...");
} catch (Exception e) {
e.printStackTrace();
}
}
return res;
}
@Override
public ArrayList getAll() {
ArrayList res=new ArrayList();
File oldFile =new File(Constants.FILE_NAME);
if(oldFile.exists()) {
try (ObjectInputStream ois=new ObjectInputStream(new FileInputStream(oldFile))){
ois.skip(8);
while(true) {
Object obj=ois.readObject();
res.add(obj);
}
} catch (EOFException e) {
System.out.println("数据加载完毕！");
} catch (Exception e) {
e.printStackTrace();
}
}
return res;
}
@Override
public boolean update(User user) {
boolean res = false;
File oldFile = new File(Constants.FILE_NAME);
File tmpFile = new File(Constants.TEMP_NAME);
if (oldFile.exists()) {
try (ObjectInputStream ois = new ObjectInputStream(new FileInputStream(oldFile));
ObjectOutputStream oos = new ObjectOutputStream(new FileOutputStream(tmpFile));) {
oos.writeLong(ois.readLong());
while (true) {
try {
Object tmp = ois.readObject();
System.out.println(user);
if (tmp != null) {
if (!tmp.equals(user)) {
System.out.println(tmp);
oos.writeObject(tmp);
} else {
oos.writeObject(user);
res = true;
}
}
} catch (EOFException e) {
break;
}
}
} catch (Exception e) {
e.printStackTrace();
res = false;
}
}
if (oldFile.exists() && tmpFile.exists()) {
oldFile.delete();
tmpFile.renameTo(oldFile);
}
return res;
}
@Override
public boolean delete(Long id) {
boolean res = false;
File oldFile = new File(Constants.FILE_NAME);
File tmpFile = new File(Constants.TEMP_NAME);
if (oldFile.exists()) {
try (ObjectInputStream ois = new ObjectInputStream(new FileInputStream(oldFile));
ObjectOutputStream oos = new ObjectOutputStream(new FileOutputStream(tmpFile));) {
oos.writeLong(ois.readLong());
while (true) {
try {
Object tmp = ois.readObject();
if (tmp != null) {
if (tmp instanceof User) {
User temp = (User) tmp;
if (!id.equals(temp.getId())) {
oos.writeObject(tmp);
}else {
res=true;
}
}
}
} catch (EOFException e) {
break;
}
}
} catch (Exception e) {
e.printStackTrace();
res = false;
}
}
if (oldFile.exists() && tmpFile.exists()) {
oldFile.delete();
tmpFile.renameTo(oldFile);
}
return res;
}
}三、mycode.entity包
User.java文件
package mycode.entity;
import java.io.Serializable;
import java.util.Objects;
public class User implements Serializable {
private static final long serialVersionUID = -5842697108263364883L;
private Long id;
private String username;
private String password;
private String repassword;
@Override
public int hashCode() {
if (this.id == null)
return Objects.hash(password, username);
return Objects.hash(id);
}
@Override
public boolean equals(Object obj) {
if (this == obj)
return true;
if (obj == null)
return false;
if (getClass() != obj.getClass())
return false;
User other = (User) obj;
if (this.id == null || other.id == null)
return Objects.equals(password, other.password) && Objects.equals(username, other.username);
else
return Objects.equals(this.id, other.id);
}
//=================================
public Long getId() {
return id;
}
public void setId(Long id) {
this.id = id;
}
public String getUsername() {
return username;
}
public String getShowPassword() {
StringBuilder sb = new StringBuilder();
for (int i = 0; i < password.length(); i++)
sb.append("*");
return sb.toString();
}
public void setUsername(String username) {
this.username = username;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
public String getRepassword() {
return repassword;
}
public void setRepassword(String repassword) {
this.repassword = repassword;
}
@Override
public String toString() {
return "User [id=" + id + ", username=" + username + ", password=" + this.getShowPassword() + "]";
}
}四、mycode.util包
ArrayList.java文件
package mycode.util;
public class ArrayList {
private Object[] arr;
private int count;
public ArrayList() {
this(10);
}
public ArrayList(int length) {
arr = new Object[length];
}
public void add(Object obj) {
arr[count++]=obj;
if(count>=arr.length) {
resize();
}
}
public Object[] getArray() {
return arr;
}
private void resize() {
Object[] res=new Object[arr.length*2];
System.arraycopy(arr, 0, res, 0, arr.length);
this.arr=res;
}
}DaoFactory.java文件
package mycode.util;
import mycode.dao.IUserDao;
import mycode.dao.UserDaoImpl;
public class DaoFactory {
private DaoFactory() {
}
private static IUserDao userDao = new UserDaoImpl();
public static IUserDao getUserDao() {
return userDao;
}
}五、mycode.trst包
Test.java文件
package test;
import java.sql.Date;
import java.util.Arrays;
public class Test1 {
public static void main(String[] args) {
// 简单类型
int[] arr1 = { 1, 2, 3, 4, 5, 6 };
int[] brr1 = new int[arr1.length * 2];
System.arraycopy(arr1, 1, brr1, 2, arr1.length - 1);
System.out.println(Arrays.toString(brr1));
// 引用类型
Object[] arr2 = new Object[3];
for (int i = 0; i < arr2.length; i++) {
arr2[i] = new Date(1659684098321L+i*1000);
}
Date[] brr2=new Date[arr2.length*2];
System.arraycopy(arr2, 0, brr2, 0, arr2.length);
((Date)arr2[0]).setYear(9000);
System.out.println(Arrays.toString(brr2));
}
}六、data文件夹
users.data文件
Readme.md说明文件
# 用户管理系统
简单实现后分析问题：
1、数据重复，要求id不允许重复。引入算法：max(id)+1是新用户的id值
2、用户注册信息中用户名称和口令不能为空,不再输入验证.所以操作之前应该对传入数据进行验证，如果验证失败则通过抛出异常阻止程序执行public void regist(UserBean user)throws Exception
3、显示所有用户信息：为了测试方便而添加的方法
- 1、传入参数：void
- 2、返回值：void
`public void showAll()throws Exception`
4、用户登录login
- 1、传入参数: UserBean其中包含的是用户输入的登录信息，应该包含用户名称和口令
- 2、返回值：boolean 登录成功则返回true，否则false
- 3、操作文件过程中可能会有异常IOException
- 4、具体的处理逻辑：遍历文件中所保存的用户信息，如果有对应的用户名和口令的对象存在，则立即中断并返回true；如果遍历整个文件都没有符合要求的对象，则返回false
`public boolean login(UserBean user)throws Exception`项目包，文件布局
实现样式
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