# 🛒 开发注册功能

---

## 1. 开发步骤

访问注册页面

提交注册数据：

- 通过表单提交数据
- 服务端验证账号是否已存在、邮箱是否已注册
- 服务端发送激活邮件

激活注册账号：

- 点击邮件中的链接，访问服务端的激活服务

## 2. 代码编写

### ① 提交注册数据

#### UserService

```java
package com.greate.community.service;

import com.greate.community.dao.UserMapper;
import com.greate.community.entity.User;
import com.greate.community.util.CommunityUtil;
import com.greate.community.util.MailClient;
import org.apache.commons.lang3.StringUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Service;
import org.thymeleaf.TemplateEngine;
import org.thymeleaf.context.Context;

import java.util.Date;
import java.util.HashMap;
import java.util.Map;
import java.util.Random;

@Service
public class UserService {

    @Autowired
    private UserMapper userMapper;

    @Autowired
    private MailClient mailClient;

    @Autowired
    private TemplateEngine templateEngine;

    // 网站域名
    @Value("${community.path.domain}")
    private String domain;

    // 项目名 http://localhost:8080/greatecommunity/......
    @Value("${server.servlet.context-path}")
    private String contextPath;

    /**
     * 根据 Id 查询用户
     * @param id
     * @return
     */
    public User findUserById (int id) {
        return userMapper.selectById(id);
    }

    /**
     * 用户注册
     * @param user
     * @return Map<String, Object> 返回错误提示消息，如果返回的 map 为空，则说明注册成功
     */
    public Map<String, Object> register(User user) {
        Map<String, Object> map = new HashMap<>();

        if (user == null) {
            throw new IllegalArgumentException("参数不能为空");
        }
        if (StringUtils.isBlank(user.getUsername())) {
            map.put("usernameMsg", "账号不能为空");
            return map;
        }

        if (StringUtils.isBlank(user.getPassword())) {
            map.put("passwordMsg", "密码不能为空");
            return map;
        }

        if (StringUtils.isBlank(user.getEmail())) {
            map.put("emailMsg", "邮箱不能为空");
            return map;
        }

        // 验证账号是否已存在
        User u = userMapper.selectByName(user.getUsername());
        if (u != null) {
            map.put("usernameMsg", "该账号已存在");
            return map;
        }

        // 验证邮箱是否已存在
        u = userMapper.selectByEmail(user.getEmail());
        if (u != null) {
            map.put("emailMsg", "该邮箱已被注册");
            return map;
        }

        // 注册用户
        user.setSalt(CommunityUtil.generateUUID().substring(0, 5)); // salt
        user.setPassword(CommunityUtil.md5(user.getPassword() + user.getSalt())); // 加盐加密
        user.setType(0); // 默认普通用户
        user.setStatus(0); // 默认未激活
        user.setActivationCode(CommunityUtil.generateUUID()); // 激活码
        // 随机头像（用户登录后可以自行修改）
        user.setHeaderUrl(String.format("http://images/nowcoder.com/head/%dt.png", new Random().nextInt(1000)));
        user.setCreateTime(new Date()); // 注册时间
        userMapper.insertUser(user);

        // 给注册用户发送激活邮件
        Context context = new Context();
        context.setVariable("email", user.getEmail());
        // http://localhost:8080/greatecommunity/activation/用户id/激活码
        String url = domain + contextPath + "/activation" + user.getId() + "/" + user.getActivationCode();
        context.setVariable("url", url);
        String content = templateEngine.process("/mail/activation", context);
        mailClient.sendMail(user.getEmail(),"激活 Greate Community 账号", content);

        return map;
    }

}
```

#### LoginController

```java
/**
 * 登录注册
 */
@Controller
public class LoginController {

    @Autowired
    UserService userService;

    /**
     * 进入注册界面
     * @return
     */
    @GetMapping("/register")
    public String getRegisterPage() {
        return "site/register";
    }

    /**
     * 注册用户
     * @param model
     * @param user
     * @return
     */
    @PostMapping("/register")
    public String register(Model model, User user) {
        Map<String, Object> map = userService.register(user);
        if (map == null || map.isEmpty()) {
            model.addAttribute("msg", "注册成功, 我们已经向您的邮箱发送了一封激活邮件，请尽快激活!");
            model.addAttribute("target", "/index");
            return "/site/operate-result";
        } else {
            model.addAttribute("usernameMsg", map.get("usernameMsg"));
            model.addAttribute("passwordMsg", map.get("passwordMsg"));
            model.addAttribute("emailMsg", map.get("emailMsg"));
            return "/site/register";
        }
    }

}
```

注册成功会跳转到一个中间界面：`operate-result`，提示用户注册成功，并前往邮箱进行激活

```html
<p>
    系统会在 <span id="seconds" class="text-danger">8</span> 秒后自动跳转,
    您也可以点击 <a id="target" th:href="@{${target}}" class="text-primary">此链接</a>, 手动跳转!
</p>
```

#### 前端通过表单提交数据

```html
<form class="mt-5" method="post" th:action="@{/register}">
	<input name = "username" />
```

SpringMVC 基于同名原则，把前端的 username 传给 user.username

```java
@PostMapping("/register")
public String register(Model model, User user)
```

### ② 激活注册账号

#### UserService

```java
/**
 * 激活用户
 * @param userId 用户 id
 * @param code 激活码
 * @return
 */
public int activation(int userId, String code) {
    User user = userMapper.selectById(userId);
    if (user.getStatus() == 1) {
        // 用户已激活
        return ACTIVATION_REPEAT;
    }
    else if (user.getActivationCode().equals(code)) {
        // 修改用户状态为已激活
        userMapper.updateStatus(userId, 1);
        return ACTIVATION_SUCCESS;
    }
    else {
        return ACTIVATION_FAILURE;
    }
}
```

#### LoginController

用户收到激活邮件后，点击邮件中的链接，则激活该用户

```java
	// 用户激活
    // http://localhost:8080/greatecommunity/activation/用户id/激活码
    @GetMapping("/activation/{userId}/{code}")
    public String activation(Model model, @PathVariable("userId") int userId, @PathVariable("code") String code) {
        int result = userService.activation(userId, code);
        if (result == ACTIVATION_SUCCESS) {
            model.addAttribute("msg", "激活成功, 您的账号已经可以正常使用!");
            model.addAttribute("target", "/login");
        }
        else if (result == ACTIVATION_REPEAT) {
            model.addAttribute("msg", "无效的操作, 您的账号已被激活过!");
            model.addAttribute("target", "/index");
        }
        else {
            model.addAttribute("msg", "激活失败, 您提供的激活码不正确!");
            model.addAttribute("target", "/index");
        }
        return "/site/operate-result";
    }
```