BaseRequestInterceptor.java

/*
 * Copyright 2013-2015 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
 *
 *      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.springframework.cloud.netflix.feign.encoding;

import feign.RequestInterceptor;
import feign.RequestTemplate;
import lombok.AccessLevel;
import lombok.Getter;
import org.springframework.util.Assert;

/**
 * The base request interceptor.
 *
 * @author Jakub Narloch
 */
public abstract class BaseRequestInterceptor implements RequestInterceptor {

    /**
     * The encoding properties.
     */
    @Getter(AccessLevel.PROTECTED)
    private final FeignClientEncodingProperties properties;

    /**
     * Creates new instance of {@link BaseRequestInterceptor}.
     *
     * @param properties the encoding properties
     */
    protected BaseRequestInterceptor(FeignClientEncodingProperties properties) {
        Assert.notNull(properties, "Properties can not be null");
        this.properties = properties;
    }

    /**
     * Adds the header if it wasn't yet specified.
     *
     * @param requestTemplate the request
     * @param name            the header name
     * @param values          the header values
     */
    protected void addHeader(RequestTemplate requestTemplate, String name, String... values) {

        if (!requestTemplate.headers().containsKey(name)) {
            requestTemplate.header(name, values);
        }
    }
}