EncodingUtil.java

/*
 * $Header: /home/jerenkrantz/tmp/commons/commons-convert/cvs/home/cvs/jakarta-commons//httpclient/src/java/org/apache/commons/httpclient/util/EncodingUtil.java,v 1.8 2004/05/13 04:01:22 mbecke Exp $
 * $Revision: 480424 $
 * $Date: 2006-11-29 06:56:49 +0100 (Wed, 29 Nov 2006) $
 *
 * ====================================================================
 *
 *  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.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 *
 */

package com.openfeint.internal.request.multipart;

import java.io.UnsupportedEncodingException;

/**
 * The home for utility methods that handle various encoding tasks.
 * 
 * @author Michael Becke
 * @author <a href="mailto:oleg@ural.ru">Oleg Kalnichevski</a>
 * 
 * @since 2.0 final
 */
public class EncodingUtil {

    /**
     * Converts the specified string to byte array of ASCII characters.
     *
     * @param data the string to be encoded
     * @return The string as a byte array.
     * 
     * @since 3.0
     */
    public static byte[] getAsciiBytes(final String data) {

        if (data == null) {
            throw new IllegalArgumentException("Parameter may not be null");
        }

        try {
            return data.getBytes("US-ASCII");
        } catch (UnsupportedEncodingException e) {
            throw new RuntimeException("HttpClient requires ASCII support");
        }
    }

    /**
     * Converts the byte array of ASCII characters to a string. This method is
     * to be used when decoding content of HTTP elements (such as response
     * headers)
     *
     * @param data the byte array to be encoded
     * @param offset the index of the first byte to encode
     * @param length the number of bytes to encode 
     * @return The string representation of the byte array
     * 
     * @since 3.0
     */
    public static String getAsciiString(final byte[] data, int offset, int length) {

        if (data == null) {
            throw new IllegalArgumentException("Parameter may not be null");
        }

        try {
            return new String(data, offset, length, "US-ASCII");
        } catch (UnsupportedEncodingException e) {
            throw new RuntimeException("HttpClient requires ASCII support");
        }
    }

    /**
     * Converts the byte array of ASCII characters to a string. This method is
     * to be used when decoding content of HTTP elements (such as response
     * headers)
     *
     * @param data the byte array to be encoded
     * @return The string representation of the byte array
     * 
     * @since 3.0
     */
    public static String getAsciiString(final byte[] data) {
        return getAsciiString(data, 0, data.length);
    }

    /**
     * Converts the specified string to a byte array.  If the charset is not supported the
     * default system charset is used.
     *
     * @param data the string to be encoded
     * @param charset the desired character encoding
     * @return The resulting byte array.
     * 
     * @since 3.0
     */
    public static byte[] getBytes(final String data, String charset) {

        if (data == null) {
            throw new IllegalArgumentException("data may not be null");
        }

        if (charset == null || charset.length() == 0) {
            throw new IllegalArgumentException("charset may not be null or empty");
        }

        try {
            return data.getBytes(charset);
        } catch (UnsupportedEncodingException e) {
            return data.getBytes();
        }
    } 
    
    /**
     * This class should not be instantiated.
     */
    private EncodingUtil() {
    }

}