spring web 跨域问题解决

1. nginx反向代理解决跨域
2. 服务端设置Response Header(响应头部)的Access-Control-Allow-Origin
3. 在需要跨域访问的类和方法中设置允许跨域访问（如Spring中使用@CrossOrigin注解）；
4. 继承使用Spring Web的CorsFilter（适用于Spring MVC、Spring Boot）
5. 实现WebMvcConfigurer接口（适用于Spring Boot）

1. filter实现，如果是在spring中使用，需要在类上添加@Component注解；如果是在spring boot中使用，需要在启动类上添加@ServletComponentScan注解。

@WebFilter("/*")
//@Component
@Order(1)
public class CorsFilter implements Filter {
    @Override
    public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain) throws IOException, ServletException {
        HttpServletResponse response = (HttpServletResponse) res;
        response.setHeader("Access-Control-Allow-Origin", "*");
        response.setHeader("Access-Control-Allow-Methods", "*");
        response.setHeader("Access-Control-Max-Age", "3600");
        response.setHeader("Access-Control-Allow-Headers", "*");
        response.setHeader("Access-Control-Allow-Credentials", "true");
        chain.doFilter(req, res);
    }
}

 2. 

@Configuration
public class WebConfig implements WebMvcConfigurer {

    @Autowired
    private CrossInterceptor crossInterceptor;

    // 第一种配置方案
    @Override
    public void addCorsMappings(CorsRegistry registry) {
        registry.addMapping("/**")
                .allowCredentials(true)
//                .allowedOrigins("*")
                .allowedHeaders("*")
                .allowedMethods("*").allowedOriginPatterns("*");
    }

    // 第二种配置方案
    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        registry.addInterceptor(crossInterceptor).addPathPatterns("/**");
    }
    
    // 第三种配置方案
    @Bean
    public CorsFilter corsFilter()
    {
        CorsConfiguration config = new CorsConfiguration();
        config.setAllowCredentials(true);
        // 设置访问源地址
        config.addAllowedOriginPattern("*");
        // 设置访问源请求头
        config.addAllowedHeader("*");
        // 设置访问源请求方法
        config.addAllowedMethod("*");
        // 有效期 1800秒
        config.setMaxAge(1800L);
        // 添加映射路径，拦截一切请求
        UrlBasedCorsConfigurationSource source = new UrlBasedCorsConfigurationSource();
        source.registerCorsConfiguration("/**", config);
        // 返回新的CorsFilter
        return new CorsFilter(source);
    }

}

@Component
class CrossInterceptor extends HandlerInterceptorAdapter {

    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        response.setHeader("Access-Control-Allow-Origin", "*");
        response.setHeader("Access-Control-Allow-Methods", "GET, POST, PUT, DELETE, OPTIONS");
        response.setHeader("Access-Control-Max-Age", "3600");
        response.setHeader("Access-Control-Allow-Headers", "*");
        response.setHeader("Access-Control-Allow-Credentials", "true");
        return true;
    }
}

 

3.

location / {
   add_header Access-Control-Allow-Origin *;
   add_header Access-Control-Allow-Headers X-Requested-With;
   add_header Access-Control-Allow-Methods GET,POST,PUT,DELETE,OPTIONS;

   if ($request_method = 'OPTIONS') {
     return 204;
   }
}