org.springframework.cloud.gateway.filter.factory.PrefixPathGatewayFilterFactory.java Source code

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Here is the source code for org.springframework.cloud.gateway.filter.factory.PrefixPathGatewayFilterFactory.java

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/*
 * Copyright 2013-2019 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.springframework.cloud.gateway.filter.factory;

import java.util.Arrays;
import java.util.List;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import org.springframework.cloud.gateway.filter.GatewayFilter;
import org.springframework.http.server.reactive.ServerHttpRequest;

import static org.springframework.cloud.gateway.support.ServerWebExchangeUtils.GATEWAY_ALREADY_PREFIXED_ATTR;
import static org.springframework.cloud.gateway.support.ServerWebExchangeUtils.GATEWAY_REQUEST_URL_ATTR;
import static org.springframework.cloud.gateway.support.ServerWebExchangeUtils.addOriginalRequestUrl;

/**
 * @author Spencer Gibb
 */
public class PrefixPathGatewayFilterFactory
        extends AbstractGatewayFilterFactory<PrefixPathGatewayFilterFactory.Config> {

    /**
     * Prefix key.
     */
    public static final String PREFIX_KEY = "prefix";

    private static final Log log = LogFactory.getLog(PrefixPathGatewayFilterFactory.class);

    public PrefixPathGatewayFilterFactory() {
        super(Config.class);
    }

    @Override
    public List<String> shortcutFieldOrder() {
        return Arrays.asList(PREFIX_KEY);
    }

    @Override
    public GatewayFilter apply(Config config) {
        return (exchange, chain) -> {

            boolean alreadyPrefixed = exchange.getAttributeOrDefault(GATEWAY_ALREADY_PREFIXED_ATTR, false);
            if (alreadyPrefixed) {
                return chain.filter(exchange);
            }
            exchange.getAttributes().put(GATEWAY_ALREADY_PREFIXED_ATTR, true);

            ServerHttpRequest req = exchange.getRequest();
            addOriginalRequestUrl(exchange, req.getURI());
            String newPath = config.prefix + req.getURI().getRawPath();

            ServerHttpRequest request = req.mutate().path(newPath).build();

            exchange.getAttributes().put(GATEWAY_REQUEST_URL_ATTR, request.getURI());

            if (log.isTraceEnabled()) {
                log.trace("Prefixed URI with: " + config.prefix + " -> " + request.getURI());
            }

            return chain.filter(exchange.mutate().request(request).build());
        };
    }

    public static class Config {

        private String prefix;

        public String getPrefix() {
            return prefix;
        }

        public void setPrefix(String prefix) {
            this.prefix = prefix;
        }

    }

}