HeadersUtils.java — netty Source File

Source Code

/*
 * Copyright 2015 The Netty Project
 *
 * The Netty Project 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:
 *
 *   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 io.netty.handler.codec;

import java.util.AbstractCollection;
import java.util.AbstractList;
import java.util.Iterator;
import java.util.List;
import java.util.Map.Entry;
import java.util.Set;

import static io.netty.util.internal.ObjectUtil.checkNotNull;

/**
 * Provides utility methods related to {@link Headers}.
 */
public final class HeadersUtils {

    private HeadersUtils() {
    }

    /**
     * {@link Headers#get(Object)} and convert each element of {@link List} to a {@link String}.
     * @param name the name of the header to retrieve
     * @return a {@link List} of header values or an empty {@link List} if no values are found.
     */
    public static <K, V> List<String> getAllAsString(Headers<K, V, ?> headers, K name) {
        final List<V> allNames = headers.getAll(name);
        return new AbstractList<String>() {
            @Override
            public String get(int index) {
                V value = allNames.get(index);
                return value != null ? value.toString() : null;
            }

            @Override
            public int size() {
                return allNames.size();
            }
        };
    }

    /**
     * {@link Headers#get(Object)} and convert the result to a {@link String}.
     * @param headers the headers to get the {@code name} from
     * @param name the name of the header to retrieve
     * @return the first header value if the header is found. {@code null} if there's no such entry.
// ... (162 more lines)