link.thingscloud.freeswitch.esl.transport.util.HeaderParser Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of freeswitch-esl Show documentation
Freeswitch Esl
There is a newer version: 2.1.0
/*
 * 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 link.thingscloud.freeswitch.esl.transport.util;

/**
 * HeaderParser class.
 *
 * @author : zhouhailin
 * @version 1.0.0
 */
public class HeaderParser {
    private HeaderParser() {
    }

    /**
     * Split a header in the form
     *      *   Header-Name: Some_header-value
     * 
     * into a String array.
     *
     * @param sb the string header to parse
     * @return a String[] array with header name at 0 and header value at 1
     */
    public static String[] splitHeader(String sb) {
        final int length = sb.length();
        int nameStart;
        int nameEnd;
        int colonEnd;
        int valueStart;
        int valueEnd;

        nameStart = findNonWhitespace(sb, 0);
        for (nameEnd = nameStart; nameEnd < length; nameEnd++) {
            char ch = sb.charAt(nameEnd);
            if (ch == ':' || Character.isWhitespace(ch)) {
                break;
            }
        }

        for (colonEnd = nameEnd; colonEnd < length; colonEnd++) {
            if (sb.charAt(colonEnd) == ':') {
                colonEnd++;
                break;
            }
        }

        valueStart = findNonWhitespace(sb, colonEnd);
        if (valueStart == length) {
            return new String[]{
                    sb.substring(nameStart, nameEnd),
                    ""
            };
        }

        valueEnd = findEndOfString(sb);
        return new String[]{
                sb.substring(nameStart, nameEnd),
                sb.substring(valueStart, valueEnd)
        };
    }

    private static int findNonWhitespace(String sb, int offset) {
        int result;
        for (result = offset; result < sb.length(); result++) {
            if (!Character.isWhitespace(sb.charAt(result))) {
                break;
            }
        }
        return result;
    }

    private static int findEndOfString(String sb) {
        int result;
        for (result = sb.length(); result > 0; result--) {
            if (!Character.isWhitespace(sb.charAt(result - 1))) {
                break;
            }
        }
        return result;
    }
}