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* Licensed to the Apache Software Foundation (ASF) under one *
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* 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 *
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* *
* 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 *
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* KIND, either express or implied. See the License for the *
* specific language governing permissions and limitations *
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package org.apache.james.mime4j.parser;
import java.io.IOException;
import java.io.InputStream;
import org.apache.james.mime4j.MimeException;
import org.apache.james.mime4j.codec.DecodeMonitor;
import org.apache.james.mime4j.stream.BodyDescriptor;
import org.apache.james.mime4j.stream.BodyDescriptorBuilder;
import org.apache.james.mime4j.stream.EntityState;
import org.apache.james.mime4j.stream.Field;
import org.apache.james.mime4j.stream.MimeConfig;
import org.apache.james.mime4j.stream.MimeTokenStream;
import org.apache.james.mime4j.stream.RecursionMode;
/**
* <p>
* Parses MIME (or RFC822) message streams of bytes or characters and reports
* parsing events to a {@link ContentHandler} instance.
* </p>
* <p>
* Typical usage:<br/>
* <pre>
* ContentHandler handler = new MyHandler();
* MimeConfig config = new MimeConfig();
* MimeStreamParser parser = new MimeStreamParser(config);
* parser.setContentHandler(handler);
* InputStream instream = new FileInputStream("mime.msg");
* try {
* parser.parse(instream);
* } finally {
* instream.close();
* }
* </pre>
*/
public class MimeStreamParser {
private ContentHandler handler = null;
private boolean contentDecoding;
private final MimeTokenStream mimeTokenStream;
public MimeStreamParser(MimeTokenStream tokenStream) {
super();
this.mimeTokenStream = tokenStream;
this.contentDecoding = false;
}
public MimeStreamParser(
final MimeConfig config,
final DecodeMonitor monitor,
final BodyDescriptorBuilder bodyDescBuilder) {
this(new MimeTokenStream(config != null ? config.clone() : new MimeConfig(),
monitor, bodyDescBuilder));
}
public MimeStreamParser(final MimeConfig config) {
this(config, null, null);
}
public MimeStreamParser() {
this(new MimeTokenStream(new MimeConfig(), null, null));
}
/**
* Determines whether this parser automatically decodes body content
* based on the on the MIME fields with the standard defaults.
*/
public boolean isContentDecoding() {
return contentDecoding;
}
/**
* Defines whether parser should automatically decode body content
* based on the on the MIME fields with the standard defaults.
*/
public void setContentDecoding(boolean b) {
this.contentDecoding = b;
}
/**
* Parses a stream of bytes containing a MIME message. Please note that if the
* {@link MimeConfig} associated with the mime stream returns a not null Content-Type
* value from its {@link MimeConfig#getHeadlessParsing()} method, the message is
* assumed to have no head section and the headless parsing mode will be used.
*
* @param instream the stream to parse.
* @throws MimeException if the message can not be processed
* @throws IOException on I/O errors.
*/
public void parse(InputStream instream) throws MimeException, IOException {
MimeConfig config = mimeTokenStream.getConfig();
if (config.getHeadlessParsing() != null) {
Field contentType = mimeTokenStream.parseHeadless(
instream, config.getHeadlessParsing());
handler.startMessage();
handler.startHeader();
handler.field(contentType);
handler.endHeader();
} else {
mimeTokenStream.parse(instream);
}
OUTER: for (;;) {
EntityState state = mimeTokenStream.getState();
switch (state) {
case T_BODY:
BodyDescriptor desc = mimeTokenStream.getBodyDescriptor();
InputStream bodyContent;
if (contentDecoding) {
bodyContent = mimeTokenStream.getDecodedInputStream();
} else {
bodyContent = mimeTokenStream.getInputStream();
}
handler.body(desc, bodyContent);
break;
case T_END_BODYPART:
handler.endBodyPart();
break;
case T_END_HEADER:
handler.endHeader();
break;
case T_END_MESSAGE:
handler.endMessage();
break;
case T_END_MULTIPART:
handler.endMultipart();
break;
case T_END_OF_STREAM:
break OUTER;
case T_EPILOGUE:
handler.epilogue(mimeTokenStream.getInputStream());
break;
case T_FIELD:
handler.field(mimeTokenStream.getField());
break;
case T_PREAMBLE:
handler.preamble(mimeTokenStream.getInputStream());
break;
case T_RAW_ENTITY:
handler.raw(mimeTokenStream.getInputStream());
break;
case T_START_BODYPART:
handler.startBodyPart();
break;
case T_START_HEADER:
handler.startHeader();
break;
case T_START_MESSAGE:
handler.startMessage();
break;
case T_START_MULTIPART:
handler.startMultipart(mimeTokenStream.getBodyDescriptor());
break;
default:
throw new IllegalStateException("Invalid state: " + state);
}
state = mimeTokenStream.next();
}
}
/**
* Determines if this parser is currently in raw mode.
*
* @return <code>true</code> if in raw mode, <code>false</code>
* otherwise.
* @see #setRaw()
*/
public boolean isRaw() {
return mimeTokenStream.isRaw();
}
/**
* Enables raw mode. In raw mode all future entities (messages
* or body parts) in the stream will be reported to the
* {@link ContentHandler#raw(InputStream)} handler method only.
* The stream will contain the entire unparsed entity contents
* including header fields and whatever is in the body.
*/
public void setRaw() {
mimeTokenStream.setRecursionMode(RecursionMode.M_RAW);
}
/**
* Enables flat mode. In flat mode rfc822 parts are not recursively
* parsed and multipart content is handled as a single "simple" stream.
*/
public void setFlat() {
mimeTokenStream.setRecursionMode(RecursionMode.M_FLAT);
}
/**
* Enables recursive mode. In this mode rfc822 parts are recursively
* parsed.
*/
public void setRecurse() {
mimeTokenStream.setRecursionMode(RecursionMode.M_RECURSE);
}
/**
* Finishes the parsing and stops reading lines.
* NOTE: No more lines will be parsed but the parser
* will still call
* {@link ContentHandler#endMultipart()},
* {@link ContentHandler#endBodyPart()},
* {@link ContentHandler#endMessage()}, etc to match previous calls
* to
* {@link ContentHandler#startMultipart(BodyDescriptor)},
* {@link ContentHandler#startBodyPart()},
* {@link ContentHandler#startMessage()}, etc.
*/
public void stop() {
mimeTokenStream.stop();
}
/**
* Sets the <code>ContentHandler</code> to use when reporting
* parsing events.
*
* @param h the <code>ContentHandler</code>.
*/
public void setContentHandler(ContentHandler h) {
this.handler = h;
}
}