1、第一种：

public class CorsFilter extends OncePerRequestFilter {

    static final String ORIGIN = "Origin";

    protected void doFilterInternal(
        HttpServletRequest request, 
        HttpServletResponse response, 
        FilterChain filterChain) throws ServletException, IOException {
    
        String origin = request.getHeader(ORIGIN);
    
        response.setHeader("Access-Control-Allow-Origin", "*");//* or origin as u prefer
        response.setHeader("Access-Control-Allow-Credentials", "true");
        response.setHeader("Access-Control-Allow-Methods", "PUT, POST, GET, OPTIONS, DELETE");
        response.setHeader("Access-Control-Max-Age", "3600");
        response.setHeader("Access-Control-Allow-Headers", "content-type, authorization");
    
        if (request.getMethod().equals("OPTIONS"))
            response.setStatus(HttpServletResponse.SC_OK);
        else 
            filterChain.doFilter(request, response);
    
    }
}

@Bean
public CorsFilter corsFilter() throws Exception {
    return new CorsFilter();
}

http
    .addFilterBefore(corsFilter(), UsernamePasswordAuthenticationFilter.class)
    .addFilterBefore(authenticationTokenFilterBean(), UsernamePasswordAuthenticationFilter.class)
    .headers()
    .cacheControl();

2、第二种：

@Configuration
public class CorsConfig {
    @Bean
    public FilterRegistrationBean corsFilter() {
        UrlBasedCorsConfigurationSource source = new UrlBasedCorsConfigurationSource();
        CorsConfiguration config = new CorsConfiguration();
        config.setAllowCredentials(true);
        // 设置你要允许的网站域名，如果全允许则设为 *
        config.addAllowedOrigin("http://localhost:4200");
        // 如果要限制 HEADER 或 METHOD 请自行更改
        config.addAllowedHeader("*");
        config.addAllowedMethod("*");
        source.registerCorsConfiguration("/**", config);
        FilterRegistrationBean bean = new FilterRegistrationBean(new CorsFilter(source));
        // 这个顺序很重要哦，为避免麻烦请设置在最前
        bean.setOrder(0);
        return bean;
    }
}

参考：

jwt-spring-security-demo
重拾后端之Spring Boot（五） -- 跨域、自定义查询及分页

更新 2020-7-8

由于使用了springboot 2.2.5.RELEASE和springcloud Hoxton.SR4，导致跨域写法有所变化，现更新如下：

@EnableWebSecurity
public class WebSecurityConfig extends WebSecurityConfigurerAdapter {

    @Override
    protected void configure(HttpSecurity http) throws Exception {
        http
            // by default uses a Bean by the name of corsConfigurationSource
            .cors().and()
            ...
    }

    @Bean
    public CorsFilter corsFilter() {
        CorsConfiguration configuration = new CorsConfiguration();
        configuration.setAllowedOrigins(Arrays.asList("*"));
        configuration.setAllowedMethods(Arrays.asList("GET", "POST", "PUT", "PATCH", "DELETE", "OPTIONS"));
        configuration.setAllowedHeaders(Arrays.asList("authorization", "content-type", "x-auth-token"));
        configuration.setExposedHeaders(Arrays.asList("x-auth-token"));
        UrlBasedCorsConfigurationSource source = new UrlBasedCorsConfigurationSource();
        source.registerCorsConfiguration("/**", configuration);
        return new CorsFilter(source);
    }
}
 

或者

@Configuration
public class CorsConfig{
    private CorsConfiguration buildConfig() {
        CorsConfiguration corsConfiguration = new CorsConfiguration();
        corsConfiguration.addAllowedOrigin("*");
        corsConfiguration.addAllowedHeader("*");
        corsConfiguration.addAllowedMethod("*");
        corsConfiguration.setAllowCredentials(true);
        return corsConfiguration;
    }

    @Bean
    public CorsFilter corsFilter() {
        UrlBasedCorsConfigurationSource source = new UrlBasedCorsConfigurationSource();
        source.registerCorsConfiguration("/**", buildConfig());
        return new CorsFilter(source);
    }
}

总结

1. 不能把上面的方法CorsFilter corsFilter()改成CorsConfigurationSource corsConfigurationSource()，因为我试了不起作用，提醒一下各位
2. 我试了网上好多人的方法，但是只有上面的才起作用，分享给大家