AuthenticationProvider的实现类与UsernamePasswordAuthenticationToken的实现类一般放在springboot项目那个位置？可以放在同一个包下面吗？

AuthenticationProvider的实现类和UsernamePasswordAuthenticationToken的实现类都可以放在springboot项目的任何位置。一般情况下，它们被放置在security包内，因为它们都与Spring Security相关。但是，您也可以将它们放置在任何其他包内，只要您在配置Spring Security时指定正确的包路径即可。

至于它们是否可以放在同一个包下面，答案是可以的。通常情况下，如果这两个类的代码是紧密相关的，则将它们放在同一个包下是有意义的。但是，如果它们的代码没有紧密的关系，则最好将它们分开放置。

相关问题

springboot 实现二维码登录

在Spring Boot中实现二维码登录可以通过以下步骤来完成：

1. 添加依赖：在`pom.xml`文件中添加`spring-boot-starter-web`和`spring-boot-starter-security`依赖。

2. 创建二维码生成工具类：可以使用第三方库，如`zxing`来生成二维码。创建一个工具类，使用该库生成二维码图片，并将图片保存到服务器上。

3. 创建登录页面：创建一个登录页面，包含一个二维码图片和一个轮询接口用于检查用户是否已扫描二维码。

4. 创建登录控制器：创建一个控制器，处理用户的登录请求。当用户扫描二维码后，前端会发送一个请求到后端，后端会验证二维码的有效性，并返回给前端一个标识表示用户已扫描二维码。

5. 创建认证提供者：创建一个认证提供者，用于验证用户的身份。在该提供者中，可以通过用户已扫描二维码的标识来判断用户是否已登录。

6. 配置Spring Security：在`application.properties`文件中配置Spring Security，设置登录页面、认证提供者等相关信息。

7. 测试登录：启动应用程序，访问登录页面，扫描二维码进行登录测试。

以上是实现二维码登录的基本步骤，具体的代码实现可以参考以下示例：

// 生成二维码工具类
public class QRCodeUtil {
    public static void generateQRCode(String text, int width, int height, String filePath) {
        try {
            BitMatrix bitMatrix = new MultiFormatWriter().encode(text, BarcodeFormat.QR_CODE, width, height);
            Path path = FileSystems.getDefault().getPath(filePath);
            MatrixToImageWriter.writeToPath(bitMatrix, "PNG", path);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

// 登录控制器
@Controller
public class LoginController {
    @GetMapping("/login")
    public String login(Model model) {
        // 生成二维码并保存到服务器
        String qrCodeText = "http://example.com/scan"; // 替换为实际的扫描地址
        QRCodeUtil.generateQRCode(qrCodeText, 200, 200, "qrcode.png"); // 替换为实际的保存路径

        model.addAttribute("qrCodeText", qrCodeText);
        return "login";
    }

    @GetMapping("/checkLogin")
    @ResponseBody
    public boolean checkLogin() {
        // 检查用户是否已扫描二维码，返回相应的标识
        return true; // 已扫描二维码
    }
}

// 认证提供者
@Component
public class CustomAuthenticationProvider implements AuthenticationProvider {
    @Override
    public Authentication authenticate(Authentication authentication) throws AuthenticationException {
        // 验证用户的身份，可以通过已扫描二维码的标识来判断用户是否已登录
        if (authentication.isAuthenticated()) {
            return authentication;
        } else {
            throw new BadCredentialsException("Invalid QR Code");
        }
    }

    @Override
    public boolean supports(Class<?> authentication) {
        return authentication.equals(UsernamePasswordAuthenticationToken.class);
    }
}

// Spring Security配置
@Configuration
@EnableWebSecurity
public class SecurityConfig extends WebSecurityConfigurerAdapter {
    @Autowired
    private CustomAuthenticationProvider authenticationProvider;

    @Override
    protected void configure(HttpSecurity http) throws Exception {
        http
            .authorizeRequests()
                .antMatchers("/login").permitAll()
                .anyRequest().authenticated()
                .and()
            .formLogin()
                .loginPage("/login")
                .and()
            .logout()
                .logoutSuccessUrl("/login")
                .and()
            .authenticationProvider(authenticationProvider);
    }
}

请注意，上述代码仅为示例，实际应用中可能需要根据具体需求进行适当的修改和扩展。

SpringBoot整合JWT 用java-jwt依赖包实现

可以通过以下步骤在Spring Boot中集成JWT：

1. 添加java-jwt依赖包到pom.xml文件中：

<dependency>
    <groupId>com.auth0</groupId>
    <artifactId>java-jwt</artifactId>
    <version>3.18.1</version>
</dependency>

2. 创建一个JWT工具类来生成和验证JWT令牌：

import com.auth0.jwt.JWT;
import com.auth0.jwt.algorithms.Algorithm;
import com.auth0.jwt.exceptions.JWTVerificationException;
import com.auth0.jwt.interfaces.DecodedJWT;

import java.util.Date;

public class JwtUtils {

    private static final long EXPIRATION_TIME = 86400000; // 24 hours
    private static final String SECRET = "mySecret";
    private static final String ISSUER = "myIssuer";

    public static String generateToken(String username) {
        Date now = new Date();
        Date expiryDate = new Date(now.getTime() + EXPIRATION_TIME);

        return JWT.create()
                .withSubject(username)
                .withIssuer(ISSUER)
                .withIssuedAt(now)
                .withExpiresAt(expiryDate)
                .sign(Algorithm.HMAC512(SECRET));
    }

    public static String getUsernameFromToken(String token) throws JWTVerificationException {
        DecodedJWT jwt = JWT.require(Algorithm.HMAC512(SECRET))
                .withIssuer(ISSUER)
                .build()
                .verify(token);

        return jwt.getSubject();
    }
}

3. 在Spring Security配置中添加JWT过滤器，以验证JWT令牌：

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.annotation.Order;
import org.springframework.http.HttpStatus;
import org.springframework.security.authentication.AuthenticationManager;
import org.springframework.security.authentication.UsernamePasswordAuthenticationToken;
import org.springframework.security.config.annotation.SecurityConfigurerAdapter;
import org.springframework.security.config.annotation.web.builders.HttpSecurity;
import org.springframework.security.config.annotation.web.configuration.WebSecurityConfigurerAdapter;
import org.springframework.security.core.Authentication;
import org.springframework.security.core.AuthenticationException;
import org.springframework.security.web.authentication.HttpStatusEntryPoint;
import org.springframework.security.web.authentication.UsernamePasswordAuthenticationFilter;

import javax.servlet.FilterChain;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

@Configuration
@Order(1)
public class JwtConfig extends SecurityConfigurerAdapter<javax.servlet.Filter, HttpSecurity> {

    @Autowired
    private JwtAuthenticationProvider jwtAuthenticationProvider;

    @Override
    public void configure(HttpSecurity http) throws Exception {
        JwtAuthenticationFilter jwtAuthenticationFilter = new JwtAuthenticationFilter();
        jwtAuthenticationFilter.setAuthenticationManager(http.getSharedObject(AuthenticationManager.class));
        jwtAuthenticationFilter.setAuthenticationFailureHandler(new JwtAuthenticationFailureHandler());
        http.addFilterBefore(jwtAuthenticationFilter, UsernamePasswordAuthenticationFilter.class);
    }

    private class JwtAuthenticationFilter extends UsernamePasswordAuthenticationFilter {

        @Override
        public Authentication attemptAuthentication(HttpServletRequest request, HttpServletResponse response) throws AuthenticationException {
            String token = request.getHeader("Authorization");

            if (token == null || !token.startsWith("Bearer ")) {
                throw new JwtAuthenticationException("Invalid JWT token");
            }

            String username = JwtUtils.getUsernameFromToken(token.substring(7));

            if (username == null) {
                throw new JwtAuthenticationException("Invalid JWT token");
            }

            return jwtAuthenticationProvider.authenticate(new UsernamePasswordAuthenticationToken(username, ""));
        }

        @Override
        protected void successfulAuthentication(HttpServletRequest request, HttpServletResponse response, FilterChain chain, Authentication authResult) throws IOException, ServletException {
            super.successfulAuthentication(request, response, chain, authResult);
            chain.doFilter(request, response);
        }
    }

    private class JwtAuthenticationFailureHandler extends HttpStatusEntryPoint {

        @Override
        public void commence(HttpServletRequest request, HttpServletResponse response, AuthenticationException authException) throws IOException, ServletException {
            response.setStatus(HttpStatus.UNAUTHORIZED.value());
        }
    }
}

4. 创建一个JwtAuthenticationProvider来验证用户名和密码：

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.security.authentication.AuthenticationProvider;
import org.springframework.security.authentication.UsernamePasswordAuthenticationToken;
import org.springframework.security.core.Authentication;
import org.springframework.security.core.AuthenticationException;
import org.springframework.security.core.userdetails.UserDetails;
import org.springframework.security.core.userdetails.UserDetailsService;
import org.springframework.security.crypto.password.PasswordEncoder;
import org.springframework.stereotype.Component;

@Component
public class JwtAuthenticationProvider implements AuthenticationProvider {

    @Autowired
    private UserDetailsService userDetailsService;

    @Autowired
    private PasswordEncoder passwordEncoder;

    @Override
    public Authentication authenticate(Authentication authentication) throws AuthenticationException {
        String username = authentication.getName();
        String password = (String) authentication.getCredentials();

        UserDetails userDetails = userDetailsService.loadUserByUsername(username);

        if (!passwordEncoder.matches(password, userDetails.getPassword())) {
            throw new JwtAuthenticationException("Invalid username or password");
        }

        return new UsernamePasswordAuthenticationToken(username, password, userDetails.getAuthorities());
    }

    @Override
    public boolean supports(Class<?> authentication) {
        return authentication.equals(UsernamePasswordAuthenticationToken.class);
    }
}

5. 在Spring Security配置中添加JwtConfig：

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.annotation.Order;
import org.springframework.security.config.annotation.authentication.builders.AuthenticationManagerBuilder;
import org.springframework.security.config.annotation.web.builders.HttpSecurity;
import org.springframework.security.config.annotation.web.configuration.WebSecurityConfigurerAdapter;

@Configuration
public class SecurityConfig extends WebSecurityConfigurerAdapter {

    @Autowired
    private JwtAuthenticationProvider jwtAuthenticationProvider;

    @Override
    protected void configure(AuthenticationManagerBuilder auth) throws Exception {
        auth.authenticationProvider(jwtAuthenticationProvider);
    }

    @Override
    protected void configure(HttpSecurity http) throws Exception {
        http.csrf().disable()
                .antMatcher("/**")
                .authorizeRequests()
                .antMatchers("/login").permitAll()
                .anyRequest().authenticated()
                .and()
                .apply(new JwtConfig());
    }
}

现在你就可以在Spring Boot应用程序中使用JWT进行身份验证了。