Solon Cloud Gateway 开发：Route 的过滤器与定制

RouteFilterFactory 是专为路由过滤拦截处理设计的接口。对应路由配置 filters

1、内置的路由过滤器

2、定制示例

• StripPrefix 过滤器定制示例（配置例：StripPrefix=1）

@Component
public class StripPrefixFilterFactory implements RouteFilterFactory {

    @Override
    public String prefix() {
        return "StripPrefix";
    }

    @Override
    public ExFilter create(String config) {
        return new StripPrefixFilter(config);
    }

    public static class StripPrefixFilter implements ExFilter {
        private int parts;

        public StripPrefixFilter(String config) {
            if (Utils.isBlank(config)) {
                throw new IllegalArgumentException("StripPrefixFilter config cannot be blank");
            }

            this.parts = Integer.parseInt(config);
        }

        @Override
        public Completable doFilter(ExContext ctx, ExFilterChain chain) {
            //目标路径重组
            List<String> pathFragments = Arrays.asList(ctx.newRequest().getPath().split("/", -1));
            String newPath = "/" + String.join("/", pathFragments.subList(parts + 1, pathFragments.size()));
            ctx.newRequest().path(newPath);

            return chain.doFilter(ctx);
        }
    }
}