001 /****************************************************************
002 * Licensed to the Apache Software Foundation (ASF) under one *
003 * or more contributor license agreements. See the NOTICE file *
004 * distributed with this work for additional information *
005 * regarding copyright ownership. The ASF licenses this file *
006 * to you under the Apache License, Version 2.0 (the *
007 * "License"); you may not use this file except in compliance *
008 * with the License. You may obtain a copy of the License at *
009 * *
010 * http://www.apache.org/licenses/LICENSE-2.0 *
011 * *
012 * Unless required by applicable law or agreed to in writing, *
013 * software distributed under the License is distributed on an *
014 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY *
015 * KIND, either express or implied. See the License for the *
016 * specific language governing permissions and limitations *
017 * under the License. *
018 ****************************************************************/
019
020 package org.apache.james.mime4j.field;
021
022 import java.util.Locale;
023
024 import org.apache.james.mime4j.codec.DecodeMonitor;
025 import org.apache.james.mime4j.dom.FieldParser;
026 import org.apache.james.mime4j.dom.field.ContentTransferEncodingField;
027 import org.apache.james.mime4j.stream.Field;
028 import org.apache.james.mime4j.util.MimeUtil;
029
030 /**
031 * Represents a <code>Content-Transfer-Encoding</code> field.
032 */
033 public class ContentTransferEncodingFieldImpl extends AbstractField implements ContentTransferEncodingField {
034
035 private boolean parsed = false;
036 private String encoding;
037
038 ContentTransferEncodingFieldImpl(Field rawField, DecodeMonitor monitor) {
039 super(rawField, monitor);
040 }
041
042 private void parse() {
043 parsed = true;
044 String body = getBody();
045 if (body != null) {
046 encoding = body.trim().toLowerCase(Locale.US);
047 } else {
048 encoding = null;
049 }
050 }
051
052 /**
053 * @see org.apache.james.mime4j.dom.field.ContentTransferEncodingField#getEncoding()
054 */
055 public String getEncoding() {
056 if (!parsed) {
057 parse();
058 }
059 return encoding;
060 }
061
062 /**
063 * Gets the encoding of the given field if. Returns the default
064 * <code>7bit</code> if not set or if <code>f</code> is
065 * <code>null</code>.
066 *
067 * @return the encoding.
068 */
069 public static String getEncoding(ContentTransferEncodingField f) {
070 if (f != null && f.getEncoding().length() != 0) {
071 return f.getEncoding();
072 }
073 return MimeUtil.ENC_7BIT;
074 }
075
076 public static final FieldParser<ContentTransferEncodingField> PARSER = new FieldParser<ContentTransferEncodingField>() {
077
078 public ContentTransferEncodingField parse(final Field rawField, final DecodeMonitor monitor) {
079 return new ContentTransferEncodingFieldImpl(rawField, monitor);
080 }
081
082 };
083 }