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2 * Licensed to the Apache Software Foundation (ASF) under one *
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6 * to you under the Apache License, Version 2.0 (the *
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10 * http://www.apache.org/licenses/LICENSE-2.0 *
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12 * Unless required by applicable law or agreed to in writing, *
13 * software distributed under the License is distributed on an *
14 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY *
15 * KIND, either express or implied. See the License for the *
16 * specific language governing permissions and limitations *
17 * under the License. *
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19
20 package org.apache.james.mime4j.message;
21
22 import org.apache.james.mime4j.MimeException;
23 import org.apache.james.mime4j.codec.Base64InputStream;
24 import org.apache.james.mime4j.codec.QuotedPrintableInputStream;
25 import org.apache.james.mime4j.descriptor.BodyDescriptor;
26 import org.apache.james.mime4j.field.AbstractField;
27 import org.apache.james.mime4j.parser.AbstractContentHandler;
28 import org.apache.james.mime4j.parser.Field;
29 import org.apache.james.mime4j.util.MimeUtil;
30
31 import java.io.InputStream;
32 import java.io.IOException;
33
34 /**
35 * Abstract implementation of ContentHandler that automates common
36 * tasks. Currently performs header parsing and applies content-transfer
37 * decoding to body parts.
38 *
39 *
40 */
41 public abstract class SimpleContentHandler extends AbstractContentHandler {
42
43 /**
44 * Called after headers are parsed.
45 */
46 public abstract void headers(Header header);
47
48 /**
49 * Called when the body of a discrete (non-multipart) entity is encountered.
50
51 * @param bd encapsulates the values (either read from the
52 * message stream or, if not present, determined implictly
53 * as described in the
54 * MIME rfc:s) of the <code>Content-Type</code> and
55 * <code>Content-Transfer-Encoding</code> header fields.
56 * @param is the contents of the body. Base64 or quoted-printable
57 * decoding will be applied transparently.
58 * @throws IOException should be thrown on I/O errors.
59 */
60 public abstract void bodyDecoded(BodyDescriptor bd, InputStream is) throws IOException;
61
62
63 /* Implement introduced callbacks. */
64
65 private Header currHeader;
66
67 /**
68 * @see org.apache.james.mime4j.parser.AbstractContentHandler#startHeader()
69 */
70 @Override
71 public final void startHeader() {
72 currHeader = new Header();
73 }
74
75 /**
76 * @see org.apache.james.mime4j.parser.AbstractContentHandler#field(Field)
77 */
78 @Override
79 public final void field(Field field) throws MimeException {
80 Field parsedField = AbstractField.parse(field.getRaw());
81 currHeader.addField(parsedField);
82 }
83
84 /**
85 * @see org.apache.james.mime4j.parser.AbstractContentHandler#endHeader()
86 */
87 @Override
88 public final void endHeader() {
89 Header tmp = currHeader;
90 currHeader = null;
91 headers(tmp);
92 }
93
94 /**
95 * @see org.apache.james.mime4j.parser.AbstractContentHandler#body(org.apache.james.mime4j.descriptor.BodyDescriptor, java.io.InputStream)
96 */
97 @Override
98 public final void body(BodyDescriptor bd, InputStream is) throws IOException {
99 if (MimeUtil.isBase64Encoding(bd.getTransferEncoding())) {
100 bodyDecoded(bd, new Base64InputStream(is));
101 }
102 else if (MimeUtil.isQuotedPrintableEncoded(bd.getTransferEncoding())) {
103 bodyDecoded(bd, new QuotedPrintableInputStream(is));
104 }
105 else {
106 bodyDecoded(bd, is);
107 }
108 }
109 }