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* http://www.apache.org/licenses/LICENSE-2.0 *
* *
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package org.apache.james.mime4j;
import java.io.IOException;
import java.io.InputStream;
/**
* <p>
* Receives notifications of the content of a plain RFC822 or MIME message.
* Implement this interface and register an instance of that implementation
* with a <code>MimeStreamParser</code> instance using its
* {@link org.apache.james.mime4j.MimeStreamParser#setContentHandler(ContentHandler)}
* method. The parser uses the <code>ContentHandler</code> instance to report
* basic message-related events like the start and end of the body of a
* part in a multipart MIME entity.
* </p>
* <p>
* Events will be generated in the order the corresponding elements occur in
* the message stream parsed by the parser. E.g.:
* <pre>
* startMessage()
* startHeader()
* field(...)
* field(...)
* ...
* endHeader()
* startMultipart()
* preamble(...)
* startBodyPart()
* startHeader()
* field(...)
* field(...)
* ...
* endHeader()
* body()
* endBodyPart()
* startBodyPart()
* startHeader()
* field(...)
* field(...)
* ...
* endHeader()
* body()
* endBodyPart()
* epilogue(...)
* endMultipart()
* endMessage()
* </pre>
* The above shows an example of a MIME message consisting of a multipart
* body containing two body parts.
* </p>
* <p>
* See MIME RFCs 2045-2049 for more information on the structure of MIME
* messages and RFC 822 and 2822 for the general structure of Internet mail
* messages.
* </p>
*
*
* @version $Id: ContentHandler.java,v 1.3 2004/10/02 12:41:10 ntherning Exp $
*/
public interface ContentHandler {
/**
* Called when a new message starts (a top level message or an embedded
* rfc822 message).
*/
void startMessage();
/**
* Called when a message ends.
*/
void endMessage();
/**
* Called when a new body part starts inside a
* <code>multipart/*</code> entity.
*/
void startBodyPart();
/**
* Called when a body part ends.
*/
void endBodyPart();
/**
* Called when a header (of a message or body part) is about to be parsed.
*/
void startHeader();
/**
* Called for each field of a header.
*
* @param fieldData the raw contents of the field
* (<code>Field-Name: field value</code>). The value will not be
* unfolded.
*/
void field(String fieldData);
/**
* Called when there are no more header fields in a message or body part.
*/
void endHeader();
/**
* Called for the preamble (whatever comes before the first body part)
* of a <code>multipart/*</code> entity.
*
* @param is used to get the contents of the preamble.
* @throws IOException should be thrown on I/O errors.
*/
void preamble(InputStream is) throws IOException;
/**
* Called for the epilogue (whatever comes after the final body part)
* of a <code>multipart/*</code> entity.
*
* @param is used to get the contents of the epilogue.
* @throws IOException should be thrown on I/O errors.
*/
void epilogue(InputStream is) throws IOException;
/**
* Called when the body of a multipart entity is about to be parsed.
*
* @param bd encapsulates the values (either read from the
* message stream or, if not present, determined implictly
* as described in the
* MIME rfc:s) of the <code>Content-Type</code> and
* <code>Content-Transfer-Encoding</code> header fields.
*/
void startMultipart(BodyDescriptor bd);
/**
* Called when the body of an entity has been parsed.
*/
void endMultipart();
/**
* Called when the body of a discrete (non-multipart) entity is about to
* be parsed.
*
* @param bd see {@link #startMultipart(BodyDescriptor)}
* @param is the contents of the body. NOTE: this is the raw body contents
* - it will not be decoded if encoded. The <code>bd</code>
* parameter should be used to determine how the stream data
* should be decoded.
* @throws IOException should be thrown on I/O errors.
*/
void body(BodyDescriptor bd, InputStream is) throws IOException;
/**
* Called when a new entity (message or body part) starts and the
* parser is in <code>raw</code> mode.
*
* @param is the raw contents of the entity.
* @throws IOException should be thrown on I/O errors.
* @see MimeStreamParser#setRaw(boolean)
*/
void raw(InputStream is) throws IOException;
}