Cors

springboot项目可以通过添加配置的方式来处理跨域：

@Configuration
public class CorsConfig implements WebMvcConfigurer {
    @Override
    public void addCorsMappings(CorsRegistry registry) {
        registry.addMapping("/**")
            .allowCredentials(true)
            .allowedOriginPatterns("*")
            .allowedMethods("GET", "POST", "PUT", "DELETE", "OPTIONS")
            .maxAge(3600);
    }
}

如果是security项目的话，需要添加以下的额外配置：

@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()
            ...
    }
    // 如果已经配置了上方针对SpringMVC的配置，则下方的配置可以省略
    @Bean
    CorsConfigurationSource corsConfigurationSource() {
        CorsConfiguration configuration = new CorsConfiguration();
        configuration.setAllowedOrigins(Arrays.asList("https://example.com"));
        configuration.setAllowedMethods(Arrays.asList("GET","POST"));
        UrlBasedCorsConfigurationSource source = new UrlBasedCorsConfigurationSource();
        source.registerCorsConfiguration("/**", configuration);
        return source;
    }
}