基于SpringBoot简单手写了一个网关

• 设计
• 跨域三件套
• • AxiosCorsFilter
  • ClassCorsConfig
  • InterceptorConfig
• 路由映射
• 接口实现

@Component
@Order(Ordered.HIGHEST_PRECEDENCE)
public class AxiosCorsFilter extends CorsFilter {
    public AxiosCorsFilter() {
        super(configurationSource());
    }

    
    private static UrlBasedCorsConfigurationSource configurationSource() {
        UrlBasedCorsConfigurationSource source = new UrlBasedCorsConfigurationSource();
        CorsConfiguration config = new CorsConfiguration();
        config.setAllowCredentials(true);
        config.addAllowedOrigin("*");
        config.addAllowedHeader("*");
        config.addAllowedMethod("*");
        source.registerCorsConfiguration("/**", config);

        return source;
    }
}

@Configuration
public class ClassCorsConfig {
    private CorsConfiguration buildConfig() {
        CorsConfiguration corsConfiguration =new CorsConfiguration();
       corsConfiguration.addAllowedOrigin("*"); // 1
       corsConfiguration.addAllowedHeader("*"); // 2
       corsConfiguration.addAllowedMethod("*"); // 3
        return corsConfiguration;
    }
 
    @Bean
    public CorsFilter corsFilter() {
//        UrlBasedCorsConfigurationSource source= new UrlBasedCorsConfigurationSource();
//       source.registerCorsConfiguration("/**", buildConfig()); // 4
       final UrlBasedCorsConfigurationSource source = new UrlBasedCorsConfigurationSource();
       final CorsConfiguration  config = new CorsConfiguration(); config.setAllowCredentials(true); 
 	  //允许cookies跨域 
 	  config.addAllowedOrigin("*");
 	 // 允许向该服务器提交请求的URI，*表示全部允许。。这里尽量限制来源域，比如http://xxxx:8080 ,以降低安全风险。。
 	  config.addAllowedHeader("*");
 	  // 允许访问的头信息,*表示全部 com.cxl.rc.smart.config.setMaxAge(18000L);
 	 
 	  //预检请求的缓存时间（秒），即在这个时间段里，对于相同的跨域请求不会再预检了
 	  config.addAllowedMethod("*");
 	  //允许提交请求的方法，*表示全部允许，也可以单独设置GET、PUT等 com.cxl.rc.smart.config.addAllowedMethod("HEAD");
 	  config.addAllowedMethod("GET");
 	  // 允许Get的请求方法
 	  config.addAllowedMethod("PUT");
 	  config.addAllowedMethod("POST");
 	  config.addAllowedMethod("DELETE");
 	  config.addAllowedMethod("PATCH"); 
 	  source.registerCorsConfiguration("/**",config); 
 	  return new CorsFilter(source); 
        
    }
}

@Configuration
public class InterceptorConfig implements WebMvcConfigurer {
    @Override
    public void addCorsMappings(CorsRegistry registry) {
        registry.addMapping("/**")
                .allowedOrigins("*")
                .allowedMethods("GET,POST,PUT,DELETE,HEAD,OPTIONS")
                .allowedHeaders("*")
                .allowCredentials(false).maxAge(3600);
    }

    @Override
    public void extendMessageConverters(List> converters) {
        converters.add(responseBodyConverter());
    }

    @Bean
    public HttpMessageConverter responseBodyConverter() {
        StringHttpMessageConverter converter = new StringHttpMessageConverter(
                Charset.forName("UTF-8"));
        return converter;
    }

}

public class RouterConfig {


    private static Map config = new HashMap<>();

    static {
    	// key是匹配的前缀
        config.put("/api","http://你要跳转的ip:端口");
    }

    public static String match(String path) throws Exception{
        Set strings = config.keySet();
        String s = null;
        for (String string : strings) {
            boolean equals = path.startsWith(string);
            if(equals){
                s = config.get(string);
            }
        }
        if(null == s){
            throw new Exception("["+ path +"]没有找到指定路由");
        }
        return s;
    }

    public static String get(String path) throws Exception{
        Set strings = config.keySet();
        for (String string : strings) {
            boolean equals = path.startsWith(string);
            if(equals){
                return string;
            }
        }
        throw new Exception("["+ path +"]没有找到指定映射");
    }

}

只是简单的实现而已，满足当前项目的需求。并没有做太多的完善，勿杠谢谢。

    @RequestMapping("**")
    public Object requests(@RequestBody(required = false) Map data, HttpServletRequest request, HttpServletResponse response) throws Exception{
        String path = request.getServletPath();
        String url = path.replaceFirst(RouterConfig.get(path), RouterConfig.match(path));

        if(request.getParameterMap().size() > 0){
            StringBuffer params = new StringBuffer(url + "?");
            Map r = request.getParameterMap();
            for (String s : r.keySet()) {
                params.append(s+"="+request.getParameter(s));
            }
            url = params.toString();
        }
        System.out.println("router >>>["+path+"] >>>>> ["+url+"]");
        HttpRequest req = HttpUtil.createRequest(Method.valueOf(request.getMethod()), url);
        req.header("token",request.getHeader("token"));
        req.header("Content-Type",request.getHeader("Content-Type"));
        req.header("Accept",request.getHeader("Accept"));
        req.header("Host",request.getHeader("Host"));
        req.header("User-Agent",request.getHeader("User-Agent"));
        if(null != data) {
            req.body(JSONUtil.toJsonStr(data));
        }

        if(url.indexOf("download")>-1){
            response.getOutputStream().write(req.execute().bodyBytes());
            return "file download success~!";
        }else{
            return req.execute().body();
        }

    }