core/src/main/java/org/apache/james/mime4j/stream/AbstractEntity.java - james-mime4j - Git at Google

 /****************************************************************
  * 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   *
  *                                                              *
  *   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  *
  * "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.stream;

 import java.io.IOException;

 import org.apache.james.mime4j.MimeException;
 import org.apache.james.mime4j.codec.DecodeMonitor;
 import org.apache.james.mime4j.io.LineReaderInputStream;
 import org.apache.james.mime4j.io.MaxHeaderLengthLimitException;
 import org.apache.james.mime4j.io.MaxHeaderLimitException;
 import org.apache.james.mime4j.io.MaxLineLimitException;
 import org.apache.james.mime4j.util.ByteArrayBuffer;
 import org.apache.james.mime4j.util.CharsetUtil;

 /**
  * Abstract MIME entity.
  */
 public abstract class AbstractEntity implements EntityStateMachine {

     protected final int startState;
     protected final int endState;
     protected final MimeEntityConfig config;
     protected final MutableBodyDescriptor body;

     protected int state;

     private final ByteArrayBuffer linebuf;

     private int lineCount;
     private RawField field;
     private boolean endOfHeader;
     private int headerCount;
     protected final DecodeMonitor monitor;

     /**
      * Internal state, not exposed.
      */
     private static final int T_IN_BODYPART = -2;
     /**
      * Internal state, not exposed.
      */
     private static final int T_IN_MESSAGE = -3;

     AbstractEntity(
             MutableBodyDescriptor body,
             int startState,
             int endState,
             MimeEntityConfig config,
             DecodeMonitor monitor) {
         this.state = startState;
         this.startState = startState;
         this.endState = endState;
         this.config = config;
         this.body = body;
         this.linebuf = new ByteArrayBuffer(64);
         this.lineCount = 0;
         this.endOfHeader = false;
         this.headerCount = 0;
         this.monitor = monitor;
     }

     public int getState() {
         return state;
     }

     /**
      * Returns the current line number or <code>-1</code> if line number
      * information is not available.
      */
     protected abstract int getLineNumber();

     protected abstract LineReaderInputStream getDataStream();

     private ByteArrayBuffer fillFieldBuffer() throws IOException, MimeException {
         if (endOfHeader)
             throw new IllegalStateException();

         int maxHeaderLen = config.getMaxHeaderLen();
         LineReaderInputStream instream = getDataStream();
         ByteArrayBuffer fieldbuf = new ByteArrayBuffer(64);

         try {
             for (;;) {
                 // If there's still data stuck in the line buffer
                 // copy it to the field buffer
                 int len = linebuf.length();
                 if (maxHeaderLen > 0 && fieldbuf.length() + len >= maxHeaderLen) {
                     throw new MaxHeaderLengthLimitException("Maximum header length limit exceeded");
                 }
                 if (len > 0) {
                     fieldbuf.append(linebuf.buffer(), 0, len);
                 }
                 linebuf.clear();
                 if (instream.readLine(linebuf) == -1) {
                     monitor(Event.HEADERS_PREMATURE_END);
                     endOfHeader = true;
                     break;
                 }
                 len = linebuf.length();
                 if (len > 0 && linebuf.byteAt(len - 1) == '\n') {
                     len--;
                 }
                 if (len > 0 && linebuf.byteAt(len - 1) == '\r') {
                     len--;
                 }
                 if (len == 0) {
                     // empty line detected
                     endOfHeader = true;
                     break;
                 }
                 lineCount++;
                 if (lineCount > 1) {
                     int ch = linebuf.byteAt(0);
                     if (ch != CharsetUtil.SP && ch != CharsetUtil.HT) {
                         // new header detected
                         break;
                     }
                 }
             }
         } catch (MaxLineLimitException e) {
             throw new MimeException(e);
         }

         return fieldbuf;
     }

     protected boolean parseField() throws MimeException, IOException {
         int maxHeaderCount = config.getMaxHeaderCount();
         // the loop is here to transparently skip invalid headers
         for (;;) {
             if (endOfHeader) {
                 return false;
             }
             if (maxHeaderCount > 0 && headerCount >= maxHeaderCount) {
                 throw new MaxHeaderLimitException("Maximum header limit exceeded");
             }

             ByteArrayBuffer fieldbuf = fillFieldBuffer();
             headerCount++;

             // Strip away line delimiter
             int origLen = fieldbuf.length();
             int len = fieldbuf.length();
             if (len > 0 && fieldbuf.byteAt(len - 1) == '\n') {
                 len--;
             }
             if (len > 0 && fieldbuf.byteAt(len - 1) == '\r') {
                 len--;
             }
             fieldbuf.setLength(len);

             try {
             	field = new RawField(fieldbuf);
             	if (field.isObsoleteSyntax()) {
             		monitor(Event.OBSOLETE_HEADER);
             	}
                 body.addField(field);
                 return true;
             } catch (MimeException e) {
                 monitor(Event.INVALID_HEADER);
                 if (config.isMalformedHeaderStartsBody()) {
 	                fieldbuf.setLength(origLen);
 	                LineReaderInputStream instream = getDataStream();
 	                if (!instream.unread(fieldbuf)) throw new MimeParseEventException(Event.INVALID_HEADER);
 	                return false;
                 }
             }
         }
     }

     /**
      * <p>Gets a descriptor for the current entity.
      * This method is valid if {@link #getState()} returns:</p>
      * <ul>
      * <li>{@link EntityStates#T_BODY}</li>
      * <li>{@link EntityStates#T_START_MULTIPART}</li>
      * <li>{@link EntityStates#T_EPILOGUE}</li>
      * <li>{@link EntityStates#T_PREAMBLE}</li>
      * </ul>
      * @return <code>BodyDescriptor</code>, not nulls
      */
     public BodyDescriptor getBodyDescriptor() {
         switch (getState()) {
         case EntityStates.T_BODY:
         case EntityStates.T_START_MULTIPART:
         case EntityStates.T_PREAMBLE:
         case EntityStates.T_EPILOGUE:
         case EntityStates.T_END_OF_STREAM:
             return body;
         default:
             throw new IllegalStateException("Invalid state :" + stateToString(state));
         }
     }

     /**
      * This method is valid, if {@link #getState()} returns {@link EntityStates#T_FIELD}.
      * @return String with the fields raw contents.
      * @throws IllegalStateException {@link #getState()} returns another
      *   value than {@link EntityStates#T_FIELD}.
      */
     public RawField getField() {
         switch (getState()) {
         case EntityStates.T_FIELD:
             return field;
         default:
             throw new IllegalStateException("Invalid state :" + stateToString(state));
         }
     }

     /**
      * Monitors the given event.
      * Subclasses may override to perform actions upon events.
      * Base implementation logs at warn.
      * @param event <code>Event</code>, not null
      * @throws MimeException subclasses may elect to throw this exception upon
      * invalid content
      * @throws IOException subclasses may elect to throw this exception
      */
     protected void monitor(Event event) throws MimeException, IOException {
         if (monitor.isListening()) {
             String message = message(event);
             if (monitor.warn(message, "ignoring")) {
                 throw new MimeParseEventException(event);
             }
         }
     }

     /**
      * Creates an indicative message suitable for display
      * based on the given event and the current state of the system.
      * @param event <code>Event</code>, not null
      * @return message suitable for use as a message in an exception
      * or for logging
      */
     protected String message(Event event) {
         final String message;
         if (event == null) {
             message = "Event is unexpectedly null.";
         } else {
             message = event.toString();
         }

         int lineNumber = getLineNumber();
         if (lineNumber <= 0)
             return message;
         else
             return "Line " + lineNumber + ": " + message;
     }

     @Override
     public String toString() {
         return getClass().getName() + " [" + stateToString(state)
         + "][" + body.getMimeType() + "][" + body.getBoundary() + "]";
     }

     /**
      * Renders a state as a string suitable for logging.
      * @param state
      * @return rendered as string, not null
      */
     public static final String stateToString(int state) {
         final String result;
         switch (state) {
             case EntityStates.T_END_OF_STREAM:
                 result = "End of stream";
                 break;
             case EntityStates.T_START_MESSAGE:
                 result = "Start message";
                 break;
             case EntityStates.T_END_MESSAGE:
                 result = "End message";
                 break;
             case EntityStates.T_RAW_ENTITY:
                 result = "Raw entity";
                 break;
             case EntityStates.T_START_HEADER:
                 result = "Start header";
                 break;
             case EntityStates.T_FIELD:
                 result = "Field";
                 break;
             case EntityStates.T_END_HEADER:
                 result = "End header";
                 break;
             case EntityStates.T_START_MULTIPART:
                 result = "Start multipart";
                 break;
             case EntityStates.T_END_MULTIPART:
                 result = "End multipart";
                 break;
             case EntityStates.T_PREAMBLE:
                 result = "Preamble";
                 break;
             case EntityStates.T_EPILOGUE:
                 result = "Epilogue";
                 break;
             case EntityStates.T_START_BODYPART:
                 result = "Start bodypart";
                 break;
             case EntityStates.T_END_BODYPART:
                 result = "End bodypart";
                 break;
             case EntityStates.T_BODY:
                 result = "Body";
                 break;
             case T_IN_BODYPART:
                 result = "Bodypart";
                 break;
             case T_IN_MESSAGE:
                 result = "In message";
                 break;
             default:
                 result = "Unknown";
                 break;
         }
         return result;
     }

 }
	/****************************************************************
	* 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 *
	* *
	* 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 *
	* "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.stream;

	import java.io.IOException;

	import org.apache.james.mime4j.MimeException;
	import org.apache.james.mime4j.codec.DecodeMonitor;
	import org.apache.james.mime4j.io.LineReaderInputStream;
	import org.apache.james.mime4j.io.MaxHeaderLengthLimitException;
	import org.apache.james.mime4j.io.MaxHeaderLimitException;
	import org.apache.james.mime4j.io.MaxLineLimitException;
	import org.apache.james.mime4j.util.ByteArrayBuffer;
	import org.apache.james.mime4j.util.CharsetUtil;

	/**
	* Abstract MIME entity.
	*/
	public abstract class AbstractEntity implements EntityStateMachine {

	protected final int startState;
	protected final int endState;
	protected final MimeEntityConfig config;
	protected final MutableBodyDescriptor body;

	protected int state;

	private final ByteArrayBuffer linebuf;

	private int lineCount;
	private RawField field;
	private boolean endOfHeader;
	private int headerCount;
	protected final DecodeMonitor monitor;

	/**
	* Internal state, not exposed.
	*/
	private static final int T_IN_BODYPART = -2;
	/**
	* Internal state, not exposed.
	*/
	private static final int T_IN_MESSAGE = -3;

	AbstractEntity(
	MutableBodyDescriptor body,
	int startState,
	int endState,
	MimeEntityConfig config,
	DecodeMonitor monitor) {
	this.state = startState;
	this.startState = startState;
	this.endState = endState;
	this.config = config;
	this.body = body;
	this.linebuf = new ByteArrayBuffer(64);
	this.lineCount = 0;
	this.endOfHeader = false;
	this.headerCount = 0;
	this.monitor = monitor;
	}

	public int getState() {
	return state;
	}

	/**
	* Returns the current line number or <code>-1</code> if line number
	* information is not available.
	*/
	protected abstract int getLineNumber();

	protected abstract LineReaderInputStream getDataStream();

	private ByteArrayBuffer fillFieldBuffer() throws IOException, MimeException {
	if (endOfHeader)
	throw new IllegalStateException();

	int maxHeaderLen = config.getMaxHeaderLen();
	LineReaderInputStream instream = getDataStream();
	ByteArrayBuffer fieldbuf = new ByteArrayBuffer(64);

	try {
	for (;;) {
	// If there's still data stuck in the line buffer
	// copy it to the field buffer
	int len = linebuf.length();
	if (maxHeaderLen > 0 && fieldbuf.length() + len >= maxHeaderLen) {
	throw new MaxHeaderLengthLimitException("Maximum header length limit exceeded");
	}
	if (len > 0) {
	fieldbuf.append(linebuf.buffer(), 0, len);
	}
	linebuf.clear();
	if (instream.readLine(linebuf) == -1) {
	monitor(Event.HEADERS_PREMATURE_END);
	endOfHeader = true;
	break;
	}
	len = linebuf.length();
	if (len > 0 && linebuf.byteAt(len - 1) == '\n') {
	len--;
	}
	if (len > 0 && linebuf.byteAt(len - 1) == '\r') {
	len--;
	}
	if (len == 0) {
	// empty line detected
	endOfHeader = true;
	break;
	}
	lineCount++;
	if (lineCount > 1) {
	int ch = linebuf.byteAt(0);
	if (ch != CharsetUtil.SP && ch != CharsetUtil.HT) {
	// new header detected
	break;
	}
	}
	}
	} catch (MaxLineLimitException e) {
	throw new MimeException(e);
	}

	return fieldbuf;
	}

	protected boolean parseField() throws MimeException, IOException {
	int maxHeaderCount = config.getMaxHeaderCount();
	// the loop is here to transparently skip invalid headers
	for (;;) {
	if (endOfHeader) {
	return false;
	}
	if (maxHeaderCount > 0 && headerCount >= maxHeaderCount) {
	throw new MaxHeaderLimitException("Maximum header limit exceeded");
	}

	ByteArrayBuffer fieldbuf = fillFieldBuffer();
	headerCount++;

	// Strip away line delimiter
	int origLen = fieldbuf.length();
	int len = fieldbuf.length();
	if (len > 0 && fieldbuf.byteAt(len - 1) == '\n') {
	len--;
	}
	if (len > 0 && fieldbuf.byteAt(len - 1) == '\r') {
	len--;
	}
	fieldbuf.setLength(len);

	try {
	field = new RawField(fieldbuf);
	if (field.isObsoleteSyntax()) {
	monitor(Event.OBSOLETE_HEADER);
	}
	body.addField(field);
	return true;
	} catch (MimeException e) {
	monitor(Event.INVALID_HEADER);
	if (config.isMalformedHeaderStartsBody()) {
	fieldbuf.setLength(origLen);
	LineReaderInputStream instream = getDataStream();
	if (!instream.unread(fieldbuf)) throw new MimeParseEventException(Event.INVALID_HEADER);
	return false;
	}
	}
	}
	}

	/**
	* <p>Gets a descriptor for the current entity.
	* This method is valid if {@link #getState()} returns:</p>
	* <ul>
	* <li>{@link EntityStates#T_BODY}</li>
	* <li>{@link EntityStates#T_START_MULTIPART}</li>
	* <li>{@link EntityStates#T_EPILOGUE}</li>
	* <li>{@link EntityStates#T_PREAMBLE}</li>
	* </ul>
	* @return <code>BodyDescriptor</code>, not nulls
	*/
	public BodyDescriptor getBodyDescriptor() {
	switch (getState()) {
	case EntityStates.T_BODY:
	case EntityStates.T_START_MULTIPART:
	case EntityStates.T_PREAMBLE:
	case EntityStates.T_EPILOGUE:
	case EntityStates.T_END_OF_STREAM:
	return body;
	default:
	throw new IllegalStateException("Invalid state :" + stateToString(state));
	}
	}

	/**
	* This method is valid, if {@link #getState()} returns {@link EntityStates#T_FIELD}.
	* @return String with the fields raw contents.
	* @throws IllegalStateException {@link #getState()} returns another
	* value than {@link EntityStates#T_FIELD}.
	*/
	public RawField getField() {
	switch (getState()) {
	case EntityStates.T_FIELD:
	return field;
	default:
	throw new IllegalStateException("Invalid state :" + stateToString(state));
	}
	}

	/**
	* Monitors the given event.
	* Subclasses may override to perform actions upon events.
	* Base implementation logs at warn.
	* @param event <code>Event</code>, not null
	* @throws MimeException subclasses may elect to throw this exception upon
	* invalid content
	* @throws IOException subclasses may elect to throw this exception
	*/
	protected void monitor(Event event) throws MimeException, IOException {
	if (monitor.isListening()) {
	String message = message(event);
	if (monitor.warn(message, "ignoring")) {
	throw new MimeParseEventException(event);
	}
	}
	}

	/**
	* Creates an indicative message suitable for display
	* based on the given event and the current state of the system.
	* @param event <code>Event</code>, not null
	* @return message suitable for use as a message in an exception
	* or for logging
	*/
	protected String message(Event event) {
	final String message;
	if (event == null) {
	message = "Event is unexpectedly null.";
	} else {
	message = event.toString();
	}

	int lineNumber = getLineNumber();
	if (lineNumber <= 0)
	return message;
	else
	return "Line " + lineNumber + ": " + message;
	}

	@Override
	public String toString() {
	return getClass().getName() + " [" + stateToString(state)
	+ "][" + body.getMimeType() + "][" + body.getBoundary() + "]";
	}

	/**
	* Renders a state as a string suitable for logging.
	* @param state
	* @return rendered as string, not null
	*/
	public static final String stateToString(int state) {
	final String result;
	switch (state) {
	case EntityStates.T_END_OF_STREAM:
	result = "End of stream";
	break;
	case EntityStates.T_START_MESSAGE:
	result = "Start message";
	break;
	case EntityStates.T_END_MESSAGE:
	result = "End message";
	break;
	case EntityStates.T_RAW_ENTITY:
	result = "Raw entity";
	break;
	case EntityStates.T_START_HEADER:
	result = "Start header";
	break;
	case EntityStates.T_FIELD:
	result = "Field";
	break;
	case EntityStates.T_END_HEADER:
	result = "End header";
	break;
	case EntityStates.T_START_MULTIPART:
	result = "Start multipart";
	break;
	case EntityStates.T_END_MULTIPART:
	result = "End multipart";
	break;
	case EntityStates.T_PREAMBLE:
	result = "Preamble";
	break;
	case EntityStates.T_EPILOGUE:
	result = "Epilogue";
	break;
	case EntityStates.T_START_BODYPART:
	result = "Start bodypart";
	break;
	case EntityStates.T_END_BODYPART:
	result = "End bodypart";
	break;
	case EntityStates.T_BODY:
	result = "Body";
	break;
	case T_IN_BODYPART:
	result = "Bodypart";
	break;
	case T_IN_MESSAGE:
	result = "In message";
	break;
	default:
	result = "Unknown";
	break;
	}
	return result;
	}

	}