shenyu-plugin/shenyu-plugin-api/src/main/java/org/apache/shenyu/plugin/api/ShenyuPlugin.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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
 *
 *     http://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.apache.shenyu.plugin.api;

import org.apache.commons.lang3.ArrayUtils;
import org.apache.shenyu.common.constant.Constants;
import org.apache.shenyu.common.enums.RpcTypeEnum;
import org.apache.shenyu.plugin.api.context.ShenyuContext;
import org.springframework.web.server.ServerWebExchange;
import reactor.core.publisher.Mono;

import java.util.Objects;

/**
 * the shenyu plugin interface.
 */
public interface ShenyuPlugin {

    /**
     * Process the Web request and (optionally) delegate to the next
     * {@code WebFilter} through the given {@link ShenyuPluginChain}.
     *
     * @param exchange the current server exchange
     * @param chain    provides a way to delegate to the next filter
     * @return {@code Mono<Void>} to indicate when request processing is complete
     */
    Mono<Void> execute(ServerWebExchange exchange, ShenyuPluginChain chain);

    /**
     * return plugin order .
     * This attribute To determine the plugin execution order in the same type plugin.
     *
     * @return int order
     */
    int getOrder();

    /**
     * acquire plugin name.
     * this is plugin name define you must Provide the right name.
     * if you impl AbstractShenyuPlugin this attribute not use.
     *
     * @return plugin name.
     */
    default String named() {
        return "";
    }

    /**
     * plugin is executed.
     * if return true this plugin can not execute.
     *
     * @param exchange the current server exchange
     * @return default false.
     */
    default boolean skip(ServerWebExchange exchange) {
        return false;
    }

    /**
     * plugin is executed.
     * if return true this plugin can not execute.
     *
     * <p>the same for:
     * <pre>
     * <code>Objects.equals(rpcType, typeA.getName())
     * || Objects.equals(rpcType, typeB.getName())
     * || Objects.equals(rpcType, type...getName())
     * </code>
     * </pre>
     *
     * @param exchange the current server exchange
     * @param rpcTypes the skip rpc type list
     * @return current rpcType == someone rpcType
     */
    default boolean skip(ServerWebExchange exchange, RpcTypeEnum... rpcTypes) {
        if (ArrayUtils.isEmpty(rpcTypes)) {
            return false;
        }
        ShenyuContext shenyuContext = exchange.getAttribute(Constants.CONTEXT);
        assert shenyuContext != null;
        String rpcType = shenyuContext.getRpcType();
        for (final RpcTypeEnum type : rpcTypes) {
            if (Objects.equals(rpcType, type.getName())) {
                return true;
            }
        }
        return false;
    }

    /**
     * the plugin execute skip except some rpc types.
     * if return true this plugin can not execute.
     *
     * <p>the same for:
     * <pre>
     * <code>!Objects.equals(rpcType, typeA.getName())
     * &amp;&amp; !Objects.equals(rpcType, typeB.getName())
     * &amp;&amp; !Objects.equals(rpcType, type...getName())
     * </code>
     * </pre>
     *
     * @param exchange the current server exchange
     * @param exceptRpcTypes the except rpc type list
     * @return current rpcType != someone exceptRpcType
     */
    default boolean skipExcept(ServerWebExchange exchange, RpcTypeEnum... exceptRpcTypes) {
        return !skip(exchange, exceptRpcTypes);
    }

    /**
     * Skip the non http call.
     * if return true this plugin can not execute.
     *
     * @param exchange the current server exchange
     * @return http/spring cloud return true, others false.
     */
    default boolean skipExceptHttpLike(ServerWebExchange exchange) {
        return !skip(exchange, RpcTypeEnum.HTTP, RpcTypeEnum.SPRING_CLOUD);
    }
}