import org.springframework.beans.factory.annotation.Autowired; import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.Configuration; import org.springframework.http.HttpMethod; import org.springframework.security.config.annotation.web.builders.HttpSecurity; import org.springframework.security.config.annotation.web.builders.WebSecurity; import org.springframework.security.config.annotation.web.configuration.EnableWebSecurity; import org.springframework.security.config.annotation.web.configuration.WebSecurityConfigurerAdapter; import org.springframework.security.crypto.bcrypt.BCryptPasswordEncoder; import org.springframework.security.crypto.password.PasswordEncoder; import org.springframework.security.web.authentication.UsernamePasswordAuthenticationFilter; @Configuration @EnableWebSecurity public class SecurityConfig extends WebSecurityConfigurerAdapter { @Bean public JwtTokenProvider jwtTokenProvider() { return new JwtTokenProvider(); } @Autowired private JwtTokenProvider jwtTokenProvider; @Override protected void configure(HttpSecurity http) throws Exception { http.csrf().disable() .addFilterBefore(new JwtTokenFilter(jwtTokenProvider), UsernamePasswordAuthenticationFilter.class) .authorizeRequests() .antMatchers("/api/").authenticated() .anyRequest().permitAll(); } @Override public void configure(WebSecurity web) throws Exception { web.ignoring().antMatchers(HttpMethod.OPTIONS, "/"); } @Bean public PasswordEncoder passwordEncoder() { return new BCryptPasswordEncoder(12); } }报错信息：Cannot resolve symbol 'JwtTokenFilter'，如何创建一个JwtTokenFilter类，让代码不报错

你需要创建一个名为 JwtTokenFilter 的类，代码如下：

import io.jsonwebtoken.ExpiredJwtException;
import org.springframework.security.authentication.UsernamePasswordAuthenticationToken;
import org.springframework.security.core.Authentication;
import org.springframework.security.core.context.SecurityContextHolder;
import org.springframework.security.web.authentication.WebAuthenticationDetailsSource;
import org.springframework.stereotype.Component;
import org.springframework.web.filter.OncePerRequestFilter;
import javax.servlet.FilterChain;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

@Component
public class JwtTokenFilter extends OncePerRequestFilter {

    private final JwtTokenProvider jwtTokenProvider;

    public JwtTokenFilter(JwtTokenProvider jwtTokenProvider) {
        this.jwtTokenProvider = jwtTokenProvider;
    }

    @Override
    protected void doFilterInternal(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, FilterChain filterChain) throws ServletException, IOException {
        String token = jwtTokenProvider.resolveToken(httpServletRequest);
        try {
            if (token != null && jwtTokenProvider.validateToken(token)) {
                Authentication auth = jwtTokenProvider.getAuthentication(token);
                if (auth != null) {
                    SecurityContextHolder.getContext().setAuthentication(auth);
                }
            }
        } catch (ExpiredJwtException e) {
            httpServletResponse.setStatus(HttpServletResponse.SC_UNAUTHORIZED);
            httpServletResponse.sendError(HttpServletResponse.SC_UNAUTHORIZED, "Token已过期");
            return;
        }

        filterChain.doFilter(httpServletRequest, httpServletResponse);
    }
}

在上面的代码中，我们创建了一个 JwtTokenFilter 类，它继承了 OncePerRequestFilter 类。JwtTokenFilter 类中包含了我们在之前创建的 JwtTokenProvider 对象，以及 doFilterInternal() 方法，该方法是实际执行 JWT 验证的地方。

在 doFilterInternal() 方法中，我们首先从请求中获取 JWT Token，并调用 JwtTokenProvider 对象中的方法来验证 Token 是否有效。如果 Token 有效，我们使用 JwtTokenProvider 对象的 getAuthentication() 方法来获取用户的身份验证对象，然后将其设置为 SecurityContext 中的认证对象。最后，我们调用 FilterChain 对象的 doFilter() 方法，以便请求可以继续进行处理。

请注意，在上面的代码中，我们使用了 @Component 注解将 JwtTokenFilter 类声明为 Spring 组件。这样，Spring 将负责创建 JwtTokenFilter 对象，并将其注入到 SecurityConfig 类中。