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 * 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   *
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 *   http://www.apache.org/licenses/LICENSE-2.0                 *
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 * 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.apache.james.mime4j.field;



/**
 * Represents a <code>Content-Transfer-Encoding</code> field.
 *
 * 
 * @version $Id: ContentTransferEncodingField.java,v 1.2 2004/10/02 12:41:11 ntherning Exp $
 */
public class ContentTransferEncodingField extends Field {
    /**
     * The <code>7bit</code> encoding.
     */
    public static final String ENC_7BIT = "7bit";
    /**
     * The <code>8bit</code> encoding.
     */
    public static final String ENC_8BIT = "8bit";
    /**
     * The <code>binary</code> encoding.
     */
    public static final String ENC_BINARY = "binary";
    /**
     * The <code>quoted-printable</code> encoding.
     */
    public static final String ENC_QUOTED_PRINTABLE = "quoted-printable";
    /**
     * The <code>base64</code> encoding.
     */
    public static final String ENC_BASE64 = "base64";
    
    private String encoding;
    
    protected ContentTransferEncodingField(String name, String body, String raw, String encoding) {
        super(name, body, raw);
        this.encoding = encoding;
    }

    /**
     * Gets the encoding defined in this field.
     * 
     * @return the encoding or an empty string if not set.
     */
    public String getEncoding() {
        return encoding;
    }
    
    /**
     * Gets the encoding of the given field if. Returns the default 
     * <code>7bit</code> if not set or if
     * <code>f</code> is <code>null</code>.
     * 
     * @return the encoding.
     */
    public static String getEncoding(ContentTransferEncodingField f) {
        if (f != null && f.getEncoding().length() != 0) {
            return f.getEncoding();
        }
        return ENC_7BIT;
    }
    
    public static class Parser implements FieldParser {
        public Field parse(final String name, final String body, final String raw) {
            final String encoding = body.trim().toLowerCase();
            return new ContentTransferEncodingField(name, body, raw, encoding);
        }
    }
}