# 簡介

這一篇文章主要是練習從零開始創建用戶，使用 JPA＋寫 Service+ 重點使用 Junit 寫 Unit Test。
唯一要實現的簡單功能是 注冊用戶 。

# 創建 Spring Boot Project 並且加入依賴

在 pom.xml 主要加入 spring web, spring data jpa, mysql driver 的依賴

這次使用 MySql 數據庫

	<dependency>
	<groupId>org.springframework.boot</groupId>
	<artifactId>spring-boot-starter-data-jpa</artifactId>
	</dependency>
	<dependency>
	<groupId>org.springframework.boot</groupId>
	<artifactId>spring-boot-starter-web</artifactId>
	</dependency>
	<dependency>
	<groupId>mysql</groupId>
	<artifactId>mysql-connector-java</artifactId>
	</dependency>

# 修改 application.properties

在 application.propeties 裡定義一下 MySQL 的配置

	spring.datasource.url=jdbc:mysql://localhost:3306/junit
	spring.datasource.username=root
	spring.datasource.password=123456
	spring.jpa.database=mysql
	spring.jpa.database-platform=org.hibernate.dialect.MySQLDialect

# 數據庫

User table：

	-- auto-generated definition
	create table user
	(
	user_id int auto_increment comment 'user id'
	primary key,
	username varchar(256) null comment 'user name',
	user_account varchar(256) not null comment 'user account number
	',
	user_password varchar(500) null comment 'user password',
	user_email varchar(1000) null comment 'user email',
	create_time datetime default CURRENT_TIMESTAMP null comment 'user created time',
	update_time datetime default CURRENT_TIMESTAMP null comment 'user info modified/ update time',
	user_status int null comment 'user status 0-active 1-inactive',
	is_deleted int null comment '1 - user is delete'
	)
	comment 'user information';

# 代碼

Domain 裡面的 > User class

	package com.example.junit_restapi.domain;

	import javax.persistence.*;
	import java.sql.Timestamp;

	@Entity
	@Data
	@AllArgsConstructor
	@NoArgsConstructor
	public class User {
	@GeneratedValue(strategy = GenerationType.IDENTITY)
	@Id
	@Column(name = "user_id")
	private int userId;
	@Basic
	@Column(name = "username")
	private String username;
	@Basic
	@Column(name = "user_account")
	private String userAccount;
	@Basic
	@Column(name = "user_password")
	private String userPassword;
	@Basic
	@Column(name = "user_email")
	private String userEmail;
	@Basic
	@Column(name = "create_time")
	private Timestamp createTime;
	@Basic
	@Column(name = "update_time")
	private Timestamp updateTime;
	@Basic
	@Column(name = "user_status")
	private Integer userStatus;
	@Basic
	@Column(name = "is_deleted")
	private Integer isDeleted;


	@Override
	public boolean equals(Object o) {
	// 省略
	// 都是自己生成的（Generate persistence mapping)
	}

	@Override
	public int hashCode() {
	// 省略
	// 都是自己生成的（Generate persistence mapping)
	}

# 命名 bug

之前創建表的時候，每個 field 命名的時候都是用 camel case，比如 userAccount 而沒有用 _ 的格式寫 user_account 。
然後在 user entity 裡面寫的也都是用 camel case，按道理來說應該是對 Map 上數據的，但最後出現這個 bug:

java.sql.SQLSyntaxErrorException: Unknown column "create_time" in 'field list'

這裡寫 unknow column "create_time" ，原本應該是 createTime 的。
結果是我忘了，hibernate 會把 camel 的字轉成 underscores，但我並沒有在 user entity class 裡面用 @Column() 去表示是對應哪一列。
實際上應該要寫成這樣的：

	@Column(name = "user_account")
	private String userAccount;
	@Column(name = "create_time")
	private Timestamp createTime;

所以後來我都直接把數據庫裡的 field 的名稱都改成 underscore 去寫了，然後直接 generate persistence mapping，懶得自己再寫一遍 User class 了。

# 注冊用戶功能

在這裡就很簡單的實現注冊用戶這一個功能，實現的邏輯：

前端輸入帳號、用戶名、和密碼
校驗輸入
把密碼加密
把數據存到數據庫裡

帳號密碼的期望規範

username 不允許重覆
username 字符長度不少於 4 位
username 不能包括特殊字符

user_account 字符長度不少於 4 位
user_account 不能包括特殊字符
(user_account 應該也不能重覆，但我沒有寫了)

password 不少於 8 位
password 要包括特殊字符
password 要有 uppercase
password 要有數字

# 檢查帳號用戶名密碼

因為只是簡單寫寫，下面代碼都沒有優化的，也沒有寫 throw exceptions 就直接返回 -1 了。

	//check if it's null value
	if (StringUtils.isAnyBlank(userAccount,username, userPassword)) {
	log.error("counldn't save user - null value");
	return -1;
	}

	//check the user account pattern and length
	String acct_pattern = "^[a-zA-Z0-9]([._-](?![._-])\|[a-zA-Z0-9]){3,18}[a-zA-Z0-9]$";

	if (userAccount.length() < 4 \|\| !userAccount.matches(acct_pattern)) {
	log.error("counldn't save user - acct name or password length problem");
	return -1;
	}

	// username length should > 4
	if (username.length() < 4 \|\| !username.matches(acct_pattern)) {
	log.error("username length should be greater or equal to 4");
	return -1;
	}

	//Check that the password is in compliance 1. correct pattern 2. length < 8
	String password_pattern = "^(?=.[0-9])(?=.[a-z])(?=.[A-Z])(?=.[@#$%^&+=])(?=\\S+$).{8,}$";
	if (!userPassword.matches(password_pattern) \|\| userPassword.length() < 8 ) {
	log.error("it didn't save user - password problem");
	return -1;
	}
	//check if the username is already exist
	List<User> user_result_list = userRepo.findUserByUsername(username);
	if(user_result_list.size() > 0) {
	log.error("counldn't save user - user_result_list");
	return -1;
	}

# 正則表達式

# 密碼：

^(?=.*[0-9])(?=.*[a-z])(?=.*[A-Z])(?=.*[@#$%^&+=])(?=\S+$).{8,}$

	^ # start-of-string
	(?=.*[0-9]) # a digit must occur at least once
	(?=.*[a-z]) # a lower case letter must occur at least once
	(?=.*[A-Z]) # an upper case letter must occur at least once
	(?=.*[@#$%^&+=]) # a special character must occur at least once
	(?=\S+$) # no whitespace allowed in the entire string
	.{8,} # anything, at least eight places though
	$ # end-of-string

# user_account & username ：

^[a-zA-Z0-9]([._-](?![._-])|[a-zA-Z0-9]){3,18}[a-zA-Z0-9]$

# StringUtils

項目裡面用到 StringUtils.isAnyBlank() ，如果要測下面這種代碼，用 StringUtils 看上去比較易懂點...

if(username == null || password == null || checkPassword == null)

在 google 裡搜 → Maven repository → apache commons utils （用最新最多 usage 的

https://mvnrepository.com/artifact/org.apache.commons/commons-lang3/3.12.0

然後把裡面的 dependency 加入到 pom.xml 配置

	<!-- https://mvnrepository.com/artifact/org.apache.commons/commons-lang3 -->
	<dependency>
	<groupId>org.apache.commons</groupId>
	<artifactId>commons-lang3</artifactId>
	<version>3.12.0</version>
	</dependency>

就可以用 StringUtils.isAnyBlank () 去測是否為 null ，並且代碼更加易懂

	public long testUser(String username, String password, String checkPassword) {
	if(StringUtils.isAnyBlank(username, password, checkPassword)){
	return -1;
	}
	return 0;
	}

# 加密密碼

在這邊只是用最簡單的方法加密，沒有用 JWT 或其他方法密碼。

	//encrypt password
	String salt = "tiff";
	String new_password = DigestUtils.md5DigestAsHex((salt + userPassword).getBytes(StandardCharsets.UTF_8));

# 創建 User 並存到數據庫

	//insert user into database
	User user = new User();
	user.setUsername(username);
	user.setUserAccount(userAccount);
	user.setUserPassword(new_password);
	userRepo.save(user);

# 完整代碼

UserRepository

	@Repository
	public interface UserRepository extends JpaRepository<User, Long> {

	@Query(value = "select u from User u where u.username = ?1")
	List<User> findUserByUsername(String username);
	}

UserService

	@Service
	public interface UserService {
	long registerUser(String userAccount, String username, String userpassword);
	}

UserServiceImpl

	@Slf4j
	@Service
	public class UserServiceImpl implements UserService{
	private final UserRepository userRepo;

	@Autowired
	public UserServiceImpl(UserRepository userRepo) {
	this.userRepo = userRepo;
	}


	@Override
	public long registerUser(String userAccount, String username, String userPassword) {
	//check if it's null value
	if (StringUtils.isAnyBlank(userAccount,username, userPassword)) {
	log.error("counldn't save user - null value");
	return -1;
	}

	//check the user account pattern and length
	String acct_pattern = "^[a-zA-Z0-9]([._-](?![._-])\|[a-zA-Z0-9]){3,18}[a-zA-Z0-9]$";

	if (userAccount.length() < 4 \|\| !userAccount.matches(acct_pattern)) {
	log.error("counldn't save user - acct name or password length problem");
	return -1;
	}

	// username length should > 4
	if (username.length() < 4 \|\| !username.matches(acct_pattern)) {
	log.error("username length should be greater or equal to 4");
	return -1;
	}

	//Check that the password is in compliance 1. correct pattern 2. length < 8
	String password_pattern = "^(?=.[0-9])(?=.[a-z])(?=.[A-Z])(?=.[@#$%^&+=])(?=\\S+$).{8,}$";
	if (!userPassword.matches(password_pattern) \|\| userPassword.length() < 8 ) {
	log.error("it didn't save user - password problem");
	return -1;
	}
	//check if the username is already exist
	List<User> user_result_list = userRepo.findUserByUsername(username);
	if(user_result_list.size() > 0) {
	log.error("counldn't save user - user_result_list");
	return -1;
	}

	//encrypt password
	String salt = "tiff";
	String new_password = DigestUtils.md5DigestAsHex((salt + userPassword).getBytes(StandardCharsets.UTF_8));

	//insert user into database
	User user = new User();
	user.setUsername(username);
	user.setUserAccount(userAccount);
	user.setUserPassword(new_password);
	userRepo.save(user);

	log.info("========User has been created-======");
	return user.getUserId();
	}
	}

# 單元測試

	@Test
	void registerUser() {
	User user = new User();
	user.setUsername("1");
	user.setUserAccount("testing123");
	user.setUserPassword("Ki_12352@932");
	user.setCreateTime(new Timestamp(new java.util.Date().getTime()));
	user.setUpdateTime(new Timestamp(new java.util.Date().getTime()));

	Assertions.assertAll("testing error",
	() -> { // username length should not <= 4
	long result = userService.registerUser(user.getUserAccount(), user.getUsername(), user.getUserPassword());
	Assertions.assertEquals(-1, result);
	},
	() -> { // username pattern check
	user.setUsername("user4$@-^");
	long result = userService.registerUser(user.getUserAccount(), user.getUsername(), user.getUserPassword());
	Assertions.assertEquals(-1, result);
	},
	() -> { // test password length less than 4
	user.setUsername("tiffany");
	user.setUserPassword("11");
	long result = userService.registerUser(user.getUserAccount(), user.getUsername(), user.getUserPassword());
	Assertions.assertEquals(-1, result);
	},
	() -> { // test password doesn't include special char
	user.setUserPassword("24359832759");
	long result = userService.registerUser(user.getUserAccount(), user.getUsername(), user.getUserPassword());
	Assertions.assertEquals(-1, result);
	},
	() -> { // test already have existed user in the db
	user.setUserPassword("Jj@12345678");
	user.setUsername("Alice");
	long result = userService.registerUser(user.getUserAccount(), user.getUsername(), user.getUserPassword());
	Assertions.assertEquals(-1, result);
	},
	() -> { // account has special char,
	user.setUserAccount("test@^&2");
	long result = userService.registerUser(user.getUserAccount(), user.getUsername(), user.getUserPassword());
	Assertions.assertEquals(-1, result, "account shouldn't have special char!");
	},
	() -> { // account length check : < 4
	user.setUserAccount("123");
	long result = userService.registerUser(user.getUserAccount(), user.getUsername(), user.getUserPassword());
	Assertions.assertEquals(-1, result, "account shouldn't have special char!");
	}
	);

	// test the successful user
	User successUser = new User();
	successUser.setUsername("junituser");
	successUser.setUserAccount("junituser001");
	successUser.setUserPassword("k_8Uj72882@5");
	successUser.setCreateTime(new Timestamp(new java.util.Date().getTime()));
	successUser.setUpdateTime(new Timestamp(new java.util.Date().getTime()));
	long success_result = userService.registerUser(successUser.getUserAccount(), successUser.getUsername(), successUser.getUserPassword());
	Assertions.assertTrue(success_result > 0);

# 測試完的數據庫長這樣

Alice 是本身就有了
經過測試，最後只加上 junituser 的那一 row

之後再練習下用 Mockito，這次先寫到這裡～