HttpHeaders.java

/*
 * JBoss, Home of Professional Open Source.
 * Copyright 2011, Red Hat, Inc., and individual contributors
 * as indicated by the @author tags. See the copyright.txt file in the
 * distribution for a full listing of individual contributors.
 *
 * This is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation; either version 2.1 of
 * the License, or (at your option) any later version.
 *
 * This software is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this software; if not, write to the Free
 * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
 */

package org.jboss.capedwarf.connect.server;

import org.apache.http.Header;
import org.apache.http.message.BasicHeader;

import java.util.Collections;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;

/**
 * Set custom http headers.
 *
 * @author <a href="mailto:ales.justin@jboss.org">Ales Justin</a>
 */
public class HttpHeaders {
    public static final String CONTENT_TYPE = "Content-Type";

    private static final ThreadLocal<Set<Header>> tlh = new ThreadLocal<Set<Header>>();

    /**
     * Get headers; read-only.
     *
     * @return the headers
     */
    public static Set<Header> getHeaders() {
        Set<Header> set = tlh.get();
        if (set == null)
            return Collections.emptySet();

        return Collections.unmodifiableSet(set);
    }

    /**
     * Cleanup.
     */
    public static void clear() {
        Set<Header> set = tlh.get();
        if (set != null) {
            tlh.remove();
            set.clear();
        }
    }

    /**
     * Set content type.
     *
     * @param type the type
     */
    public static void setContentType(String type) {
        for (Header h : getHeaders()) {
            if (h.getName().equals(CONTENT_TYPE))
                throw new IllegalArgumentException("Content type already set!");
        }

        addHeader(CONTENT_TYPE, type);
    }

    /**
     * Add header.
     *
     * @param name  the name
     * @param value the value
     */
    public static void addHeader(String name, String value) {
        if (name == null)
            throw new IllegalArgumentException("Null name");
        if (value == null)
            throw new IllegalArgumentException("Null value");

        addHeader(new BasicHeader(name, value));
    }

    /**
     * Add header.
     *
     * @param header the header
     */
    public static void addHeader(Header header) {
        if (header == null)
            throw new IllegalArgumentException("Null header");

        Set<Header> set = tlh.get();
        if (set == null) {
            set = new HashSet<Header>();
            tlh.set(set);
        }
        set.add(header);
    }

    /**
     * Add headers.
     *
     * @param headers the headers
     */
    public static void addHeaders(Map<String, String> headers) {
        if (headers == null)
            throw new IllegalArgumentException("Null headers");

        boolean success = false;
        try {
            for (Map.Entry<String, String> entry : headers.entrySet())
                addHeader(entry.getKey(), entry.getValue());
            success = true;
        } finally {
            if (success == false)
                clear();
        }
    }

    /**
     * Add headers.
     *
     * @param headers the headers
     */
    public static void addHeaders(Set<Header> headers) {
        if (headers == null)
            throw new IllegalArgumentException("Null headers");

        boolean success = false;
        try {
            for (Header header : headers)
                addHeader(header);
            success = true;
        } finally {
            if (success == false)
                clear();
        }
    }
}