<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-dependencies</artifactId>
    <version>2024.0.0</version>
    <type>pom</type>
    <scope>import</scope>
</dependency>

<dependencies>
    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-starter-netflix-eureka-server</artifactId>
    </dependency>
</dependencies>

@SpringBootApplication
@EnableEurekaServer
public class EurekaApplication {
    public static void main(String[] args) {
        SpringApplication.run(EurekaApplication.class, args);
    }
}

@Configuration
public class BeanConfiguration {

    @Bean
    @LoadBalanced
    public RestTemplate restTemplate() {
        return new RestTemplate();
    }
}

@Override
public UserBorrowDetail getUserBorrowDetailByUid(int uid) {
    List<Borrow> borrow = borrowMapper.getBorrowByUid(uid);
    RestTemplate restTemplate = new RestTemplate();
    User user = restTemplate.getForObject("http://userservice/user/"+uid, User.class);
    List<Book> bookList = borrow
            .stream()
            .map(b -> restTemplate.getForObject("http://bookservice/book/"+b.getBid(), Book.class))
            .collect(Collectors.toList());
    return new UserBorrowDetail(user, bookList);
}

public class LoadBalancerConfig {
      //将官方提供的 RandomLoadBalancer 注册为Bean
    @Bean
    public ReactorLoadBalancer<ServiceInstance> randomLoadBalancer(Environment environment, LoadBalancerClientFactory loadBalancerClientFactory){
        String name = environment.getProperty(LoadBalancerClientFactory.PROPERTY_NAME);
        return new RandomLoadBalancer(loadBalancerClientFactory.getLazyProvider(name, ServiceInstanceListSupplier.class), name);
    }
}

@Configuration
@LoadBalancerClient(value = "userservice",
                    configuration = LoadBalancerConfig.class)
public class BeanConfiguration {

    @Bean
    @LoadBalanced
    public RestTemplate restTemplate() {
        return new RestTemplate();
    }
}

@SpringBootApplication
@EnableFeignClients
public class SomeApplication {
    public static void main(String[] args) {
        SpringApplication.run(SomeApplication.class, args);
    }
}

@FeignClient("userservice")   // 声明为userservice服务的HTTP请求客户端
public interface UserClient {

      // 路径保证和UserService微服务提供的一致即可
    @RequestMapping("/user/{uid}")
    User getUserById(@PathVariable("uid") int uid);  // 参数和返回值也保持一致
}

@Resource
UserClient userClient;

@Override
public UserBorrowDetail getUserBorrowDetailByUid(int uid) {

    // RestTemplate方法
    RestTemplate template = new RestTemplate();
    User user = template.getForObject("http://userservice/user/"+uid, User.class);
    // OpenFeign方法，更直观的方法调用
    User user = userClient.getUserById(uid);

}

public class MybatisUtil {

    //在类加载时就进行创建
    private static SqlSessionFactory sqlSessionFactory;
    static {
        try {
            sqlSessionFactory = new SqlSessionFactoryBuilder().build(new FileInputStream("mybatis-config.xml"));
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        }
    }

    /**
     * 获取一个新的会话
     * @param autoCommit 是否开启自动提交（跟JDBC是一样的，如果不自动提交，则会变成事务操作）
     * @return SqlSession对象
     */
    public static SqlSession getSession(boolean autoCommit){
        return sqlSessionFactory.openSession(autoCommit);
    }
}

@Resource
JavaMailSender sender;

@PostMapping("/verification-email")
public String sendVerificationEmail(@RequestParam String targetEmail,
                                    HttpSession session) {
        SimpleMailMessage message = new SimpleMailMessage();
        message.setSubject(EMAIL_TITLE);
        int vCode = getVerificationCode();
        session.setAttribute("vcode", vCode);
        session.setAttribute("uemail", email);

        message.setText(EMAIL_CONTEXT + code);
        message.setTo(targetEmail);
        message.setFrom(EMAIL_SERVEREMAIL); // 与配置文件中的保持一致

        sender.send(message);
        return "发送成功"; // 前端弹窗可以接受此参数
}

@PostMapping("/register")
public String register(@RequestParam String username,
                       @RequestParam String email,
                       @RequestParam String code,
                       @RequestParam String password,
                       HttpSession session) {
    String sessionCode = session.getAttribute("vcode").toString;
    String sessionEmail = session.getAttribute("uemail").toString;

    if (sessionCode == null) {
        return "验证码为空";
    }
    if (!sessionCode.equals(code)) {
        return "验证码错误！";
    }
    if (!sessionEmail.equals(email)) {
        return "请获取验证码";
    }
}

package com.example.init
public class SecurityInitializer extends AbstractSecurityWebApplicationInitializer {
    //不用重写任何内容
      //这里实际上会自动注册一个Filter，SpringSecurity底层就是依靠N个过滤器实现的，我们之后再探讨
}

package com.example.config
@Configuration
@EnableWebSecurity   //开启WebSecurity相关功能
public class SecurityConfiguration {
        
}

@Override
protected Class<?>[] getRootConfigClasses() {
    return new Class[]{MainConfiguration.class, SecurityConfiguration.class};
}

@Configuration
@EnableWebSecurity
public class SecurityConfiguration {
    
      //将BCryptPasswordEncoder直接注册为Bean，Security会自动进行选择
    @Bean
    public PasswordEncoder passwordEncoder(){
        return new BCryptPasswordEncoder();
    }
}

encoder.encode(yourPassword);

@Configuration
@EnableWebSecurity
public class SecurityConfiguration {

    @Bean
    public SecurityFilterChain filterChain(HttpSecurity http) throws Exception {
        return http
                .csfr(conf -> {
                    // 关闭CSFR
                    conf.disable();
                })
    }
}

@Configuration
@EnableWebSecurity
public class SecurityConfiguration {

    @Bean
    public SecurityFilterChain filterChain(HttpSecurity http) throws Exception {
        return http
                // 验证请求拦截和放行配置
                .authorizeHttpRequests(auth -> {
                    // 将所有请求全部拦截，一律需要验证
                    auth.anyRequest().authenticated();    
                })
                // 表单登录相关配置
                .formLogin(conf -> {
                    conf.loginPage("/login");   // 将登录页设置为我们自己的登录页面
                    conf.loginProcessingUrl("/doLogin"); // 登录表单提交的地址，可以自定义
                    conf.defaultSuccessUrl("/");   // 登录成功后跳转的页面
                    conf.permitAll();    // 将登录相关的地址放行，否则未登录的用户无法进入登录界面
                      // 用户名和密码的表单字段名称
                    conf.usernameParameter("username");
                    conf.passwordParameter("password");
                })
                // 退出登录
                .logout(conf -> {
                    ...
                })
                .build();
    }
}

@Configuration
@EnableWebSecurity
public class SecurityConfiguration {

    @Bean
    public SecurityFilterChain filterChain(HttpSecurity http) throws Exception {
        return http
                .rememberMe(conf -> {
                    conf.alwaysRemember(false);
                })
 

@Controller   //直接添加注解即可
public class HelloController {

    @RequestMapping("/index")   //直接填写访问路径
    public ModelAndView index(){
        ModelAndView modelAndView = new ModelAndView("index");
        modelAndView.getModel().put("arg", "value");   //将name传递给Model
        return modelAndView;
          //返回后会经过视图解析器进行处理
    }

    @RequestMapping(value = "/index")
    public String index(Model model){  //这里不仅仅可以是Model，还可以是Map、ModelMap
        model.addAttribute("arg", "value");
        return "index";
    }
}

@RequestMapping("/index")
public String index(){
    return "redirect:page";
}

@RequestMapping("/index")
public String index(){
    return "forward:home";
}

@RequestMapping("/index/{str}")
public String index(@PathVariable String str) {
    System.out.println(str);
    return "index";
}

public class MainInitializer extends AbstractAnnotationConfigDispatcherServletInitializer {

    ...

    @Override
    protected void customizeRegistration(ServletRegistration.Dynamic registration) {
          // 直接通过registration配置Multipart相关配置，必须配置临时上传路径，建议选择方便打开的
        // 同样可以设置其他属性：maxFileSize, maxRequestSize, fileSizeThreshold
        registration.setMultipartConfig(new MultipartConfigElement("/path/to/save"));
    }
}

@RequestMapping(value = "/upload", method = RequestMethod.POST)
@ResponseBody
public String upload(@RequestParam MultipartFile file) throws IOException {
    File fileObj = new File("filename.png");
    file.transferTo(fileObj);
    System.out.println("用户上传的文件已保存到："+fileObj.getAbsolutePath());
    return "文件上传成功！";
}