core/src/main/java/org/apache/james/mime4j/util/MimeUtil.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.util;

 import static java.time.temporal.ChronoField.DAY_OF_MONTH;
 import static java.time.temporal.ChronoField.DAY_OF_WEEK;
 import static java.time.temporal.ChronoField.HOUR_OF_DAY;
 import static java.time.temporal.ChronoField.MILLI_OF_SECOND;
 import static java.time.temporal.ChronoField.MINUTE_OF_HOUR;
 import static java.time.temporal.ChronoField.MONTH_OF_YEAR;
 import static java.time.temporal.ChronoField.OFFSET_SECONDS;
 import static java.time.temporal.ChronoField.SECOND_OF_MINUTE;
 import static java.time.temporal.ChronoField.YEAR;

 import java.text.DateFormat;
 import java.text.FieldPosition;
 import java.text.SimpleDateFormat;
 import java.time.ZoneId;
 import java.time.format.DateTimeFormatter;
 import java.time.format.DateTimeFormatterBuilder;
 import java.time.format.ResolverStyle;
 import java.time.format.SignStyle;
 import java.util.Date;
 import java.util.GregorianCalendar;
 import java.util.HashMap;
 import java.util.Locale;
 import java.util.Map;
 import java.util.Random;
 import java.util.TimeZone;

 import org.apache.james.mime4j.codec.DecodeMonitor;
 import org.apache.james.mime4j.codec.DecoderUtil;

 /**
  * A utility class, which provides some MIME related application logic.
  */
 public final class MimeUtil {

     /**
      * The <code>quoted-printable</code> encoding.
      */
     public static final String ENC_QUOTED_PRINTABLE = "quoted-printable";
     /**
      * The <code>binary</code> encoding.
      */
     public static final String ENC_BINARY = "binary";
     /**
      * The <code>base64</code> encoding.
      */
     public static final String ENC_BASE64 = "base64";
     /**
      * The <code>8bit</code> encoding.
      */
     public static final String ENC_8BIT = "8bit";
     /**
      * The <code>7bit</code> encoding.
      */
     public static final String ENC_7BIT = "7bit";

     // used to create unique ids
     private static final Random random = new Random();

     // used to create unique ids
     private static int counter = 0;

     private MimeUtil() {
         // this is an utility class to be used statically.
         // this constructor protect from instantiation.
     }

     /**
      * Returns, whether the given two MIME types are identical.
      */
     public static boolean isSameMimeType(String pType1, String pType2) {
         return pType1 != null  &&  pType2 != null  &&  pType1.equalsIgnoreCase(pType2);
     }

     /**
      * Returns true, if the given MIME type is that of a message.
      */
     public static boolean isMessage(String pMimeType) {
         return pMimeType != null  &&  pMimeType.equalsIgnoreCase("message/rfc822");
     }

     /**
      * Return true, if the given MIME type indicates a multipart entity.
      */
     public static boolean isMultipart(String pMimeType) {
         return pMimeType != null  &&  pMimeType.toLowerCase().startsWith("multipart/");
     }

     /**
      * Returns, whether the given transfer-encoding is "base64".
      */
     public static boolean isBase64Encoding(String pTransferEncoding) {
         return ENC_BASE64.equalsIgnoreCase(pTransferEncoding);
     }

     /**
      * Returns, whether the given transfer-encoding is "quoted-printable".
      */
     public static boolean isQuotedPrintableEncoded(String pTransferEncoding) {
         return ENC_QUOTED_PRINTABLE.equalsIgnoreCase(pTransferEncoding);
     }

     /**
      * Creates a new unique message boundary string that can be used as boundary
      * parameter for the Content-Type header field of a message.
      *
      * @return a new unique message boundary string.
      */
     /* TODO - From rfc2045:
      * Since the hyphen character ("-") may be represented as itself in the
      * Quoted-Printable encoding, care must be taken, when encapsulating a
      * quoted-printable encoded body inside one or more multipart entities,
      * to ensure that the boundary delimiter does not appear anywhere in the
      * encoded body.  (A good strategy is to choose a boundary that includes
      * a character sequence such as "=_" which can never appear in a
      * quoted-printable body.  See the definition of multipart messages in
      * RFC 2046.)
      */
     public static String createUniqueBoundary() {
         StringBuilder sb = new StringBuilder();
         sb.append("-=Part.");
         sb.append(Integer.toHexString(nextCounterValue()));
         sb.append('.');
         sb.append(Long.toHexString(random.nextLong()));
         sb.append('.');
         sb.append(Long.toHexString(System.currentTimeMillis()));
         sb.append('.');
         sb.append(Long.toHexString(random.nextLong()));
         sb.append("=-");
         return sb.toString();
     }

     /**
      * Creates a new unique message identifier that can be used in message
      * header field such as Message-ID or In-Reply-To. If the given host name is
      * not <code>null</code> it will be used as suffix for the message ID
      * (following an at sign).
      *
      * The resulting string is enclosed in angle brackets (&lt; and &gt;);
      *
      * @param hostName host name to be included in the message ID or
      *            <code>null</code> if no host name should be included.
      * @return a new unique message identifier.
      */
     public static String createUniqueMessageId(String hostName) {
         StringBuilder sb = new StringBuilder("<Mime4j.");
         sb.append(Integer.toHexString(nextCounterValue()));
         sb.append('.');
         sb.append(Long.toHexString(random.nextLong()));
         sb.append('.');
         sb.append(Long.toHexString(System.currentTimeMillis()));
         if (hostName != null) {
             sb.append('@');
             sb.append(hostName);
         }
         sb.append('>');
         return sb.toString();
     }

     /**
      * Formats the specified date into a RFC 822 date-time string.
      *
      * @param date
      *            date to be formatted into a string.
      * @param zone
      *            the time zone to use or <code>null</code> to use the default
      *            time zone.
      * @return the formatted time string.
      */
     public static String formatDate(Date date, TimeZone zone) {
         return RFC822_DATE_FORMAT
             .withZone(zone(zone))
             .format(date.toInstant());
     }

     private static ZoneId zone(TimeZone zone) {
         if (zone == null) {
             return TimeZone.getDefault().toZoneId();
         } else {
             return zone.toZoneId();
         }
     }

     /**
      * Splits the specified string into a multiple-line representation with
      * lines no longer than 76 characters (because the line might contain
      * encoded words; see <a href='http://www.faqs.org/rfcs/rfc2047.html'>RFC
      * 2047</a> section 2). If the string contains non-whitespace sequences
      * longer than 76 characters a line break is inserted at the whitespace
      * character following the sequence resulting in a line longer than 76
      * characters.
      *
      * @param s
      *            string to split.
      * @param usedCharacters
      *            number of characters already used up. Usually the number of
      *            characters for header field name plus colon and one space.
      * @return a multiple-line representation of the given string.
      */
     public static String fold(String s, int usedCharacters) {
         final int maxCharacters = 76;

         final int length = s.length();
         if (usedCharacters + length <= maxCharacters)
             return s;

         StringBuilder sb = new StringBuilder();

         int lastLineBreak = -usedCharacters;
         int wspIdx = indexOfWsp(s, 0);
         while (true) {
             if (wspIdx == length) {
                 sb.append(s.substring(Math.max(0, lastLineBreak)));
                 return sb.toString();
             }

             int nextWspIdx = indexOfWsp(s, wspIdx + 1);

             if (nextWspIdx - lastLineBreak > maxCharacters) {
                 sb.append(s, Math.max(0, lastLineBreak), wspIdx);
                 sb.append("\r\n");
                 lastLineBreak = wspIdx;
             }

             wspIdx = nextWspIdx;
         }
     }

     /**
      * Unfold a multiple-line representation into a single line.
      *
      * @param s
      *            string to unfold.
      * @return unfolded string.
      */
     public static String unfold(String s) {
         final int length = s.length();
         for (int idx = 0; idx < length; idx++) {
             char c = s.charAt(idx);
             if (c == '\r' || c == '\n') {
                 return unfold0(s, idx);
             }
         }

         return s;
     }

     /**
     Unfold and decode header value
      */
     public static String unscrambleHeaderValue(String headerValue) {
         return DecoderUtil.decodeEncodedWords(
             MimeUtil.unfold(headerValue),
             DecodeMonitor.SILENT);
     }

     private static String unfold0(String s, int crlfIdx) {
         final int length = s.length();
         StringBuilder sb = new StringBuilder(length);

         if (crlfIdx > 0) {
             sb.append(s, 0, crlfIdx);
         }

         int lastLineBreak = crlfIdx;
         for (int idx = crlfIdx + 1; idx < length; idx++) {
             char c = s.charAt(idx);
             if (c == '\r' || c == '\n') {
                 if (idx > lastLineBreak + 1) {
                     sb.append(s, lastLineBreak + 1, idx);
                 }
                 lastLineBreak = idx;
             }
         }
         if (lastLineBreak < s.length() - 1 && s.length() > 0) {
             sb.append(s, lastLineBreak + 1, s.length());
         }

         return sb.toString();
     }

     private static int indexOfWsp(String s, int fromIndex) {
         final int len = s.length();
         for (int index = fromIndex; index < len; index++) {
             char c = s.charAt(index);
             if (c == ' ' || c == '\t')
                 return index;
         }
         return len;
     }

     private static synchronized int nextCounterValue() {
         return counter++;
     }

     private static final int INITIAL_YEAR = 1970;
     public static final DateTimeFormatter RFC822_DATE_FORMAT = new DateTimeFormatterBuilder()
         .parseCaseInsensitive()
         .parseLenient()
         .appendText(DAY_OF_WEEK, dayOfWeek())
         .appendLiteral(", ")
         .appendValue(DAY_OF_MONTH, 1, 2, SignStyle.NOT_NEGATIVE)
         .appendLiteral(' ')
         .appendText(MONTH_OF_YEAR, monthOfYear())
         .appendLiteral(' ')
         .appendValueReduced(YEAR, 4, 4, INITIAL_YEAR)
         .appendLiteral(' ')
         .appendValue(HOUR_OF_DAY, 2)
         .appendLiteral(':')
         .appendValue(MINUTE_OF_HOUR, 2)
         .appendLiteral(':')
         .appendValue(SECOND_OF_MINUTE, 2)
         .appendLiteral(' ')
         .appendOffset("+HHMM", "+0000")
         .toFormatter()
         .withZone(TimeZone.getDefault().toZoneId())
         .withLocale(Locale.US);

     private static Map<Long, String> monthOfYear() {
         HashMap<Long, String> result = new HashMap<>();
         result.put(1L, "Jan");
         result.put(2L, "Feb");
         result.put(3L, "Mar");
         result.put(4L, "Apr");
         result.put(5L, "May");
         result.put(6L, "Jun");
         result.put(7L, "Jul");
         result.put(8L, "Aug");
         result.put(9L, "Sep");
         result.put(10L, "Oct");
         result.put(11L, "Nov");
         result.put(12L, "Dec");
         return result;
     }

     private static Map<Long, String> dayOfWeek() {
         HashMap<Long, String> result = new HashMap<>();
         result.put(1L, "Mon");
         result.put(2L, "Tue");
         result.put(3L, "Wed");
         result.put(4L, "Thu");
         result.put(5L, "Fri");
         result.put(6L, "Sat");
         result.put(7L, "Sun");
         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.util;

	import static java.time.temporal.ChronoField.DAY_OF_MONTH;
	import static java.time.temporal.ChronoField.DAY_OF_WEEK;
	import static java.time.temporal.ChronoField.HOUR_OF_DAY;
	import static java.time.temporal.ChronoField.MILLI_OF_SECOND;
	import static java.time.temporal.ChronoField.MINUTE_OF_HOUR;
	import static java.time.temporal.ChronoField.MONTH_OF_YEAR;
	import static java.time.temporal.ChronoField.OFFSET_SECONDS;
	import static java.time.temporal.ChronoField.SECOND_OF_MINUTE;
	import static java.time.temporal.ChronoField.YEAR;

	import java.text.DateFormat;
	import java.text.FieldPosition;
	import java.text.SimpleDateFormat;
	import java.time.ZoneId;
	import java.time.format.DateTimeFormatter;
	import java.time.format.DateTimeFormatterBuilder;
	import java.time.format.ResolverStyle;
	import java.time.format.SignStyle;
	import java.util.Date;
	import java.util.GregorianCalendar;
	import java.util.HashMap;
	import java.util.Locale;
	import java.util.Map;
	import java.util.Random;
	import java.util.TimeZone;

	import org.apache.james.mime4j.codec.DecodeMonitor;
	import org.apache.james.mime4j.codec.DecoderUtil;

	/**
	* A utility class, which provides some MIME related application logic.
	*/
	public final class MimeUtil {

	/**
	* The <code>quoted-printable</code> encoding.
	*/
	public static final String ENC_QUOTED_PRINTABLE = "quoted-printable";
	/**
	* The <code>binary</code> encoding.
	*/
	public static final String ENC_BINARY = "binary";
	/**
	* The <code>base64</code> encoding.
	*/
	public static final String ENC_BASE64 = "base64";
	/**
	* The <code>8bit</code> encoding.
	*/
	public static final String ENC_8BIT = "8bit";
	/**
	* The <code>7bit</code> encoding.
	*/
	public static final String ENC_7BIT = "7bit";

	// used to create unique ids
	private static final Random random = new Random();

	// used to create unique ids
	private static int counter = 0;

	private MimeUtil() {
	// this is an utility class to be used statically.
	// this constructor protect from instantiation.
	}

	/**
	* Returns, whether the given two MIME types are identical.
	*/
	public static boolean isSameMimeType(String pType1, String pType2) {
	return pType1 != null && pType2 != null && pType1.equalsIgnoreCase(pType2);
	}

	/**
	* Returns true, if the given MIME type is that of a message.
	*/
	public static boolean isMessage(String pMimeType) {
	return pMimeType != null && pMimeType.equalsIgnoreCase("message/rfc822");
	}

	/**
	* Return true, if the given MIME type indicates a multipart entity.
	*/
	public static boolean isMultipart(String pMimeType) {
	return pMimeType != null && pMimeType.toLowerCase().startsWith("multipart/");
	}

	/**
	* Returns, whether the given transfer-encoding is "base64".
	*/
	public static boolean isBase64Encoding(String pTransferEncoding) {
	return ENC_BASE64.equalsIgnoreCase(pTransferEncoding);
	}

	/**
	* Returns, whether the given transfer-encoding is "quoted-printable".
	*/
	public static boolean isQuotedPrintableEncoded(String pTransferEncoding) {
	return ENC_QUOTED_PRINTABLE.equalsIgnoreCase(pTransferEncoding);
	}

	/**
	* Creates a new unique message boundary string that can be used as boundary
	* parameter for the Content-Type header field of a message.
	*
	* @return a new unique message boundary string.
	*/
	/* TODO - From rfc2045:
	* Since the hyphen character ("-") may be represented as itself in the
	* Quoted-Printable encoding, care must be taken, when encapsulating a
	* quoted-printable encoded body inside one or more multipart entities,
	* to ensure that the boundary delimiter does not appear anywhere in the
	* encoded body. (A good strategy is to choose a boundary that includes
	* a character sequence such as "=_" which can never appear in a
	* quoted-printable body. See the definition of multipart messages in
	* RFC 2046.)
	*/
	public static String createUniqueBoundary() {
	StringBuilder sb = new StringBuilder();
	sb.append("-=Part.");
	sb.append(Integer.toHexString(nextCounterValue()));
	sb.append('.');
	sb.append(Long.toHexString(random.nextLong()));
	sb.append('.');
	sb.append(Long.toHexString(System.currentTimeMillis()));
	sb.append('.');
	sb.append(Long.toHexString(random.nextLong()));
	sb.append("=-");
	return sb.toString();
	}

	/**
	* Creates a new unique message identifier that can be used in message
	* header field such as Message-ID or In-Reply-To. If the given host name is
	* not <code>null</code> it will be used as suffix for the message ID
	* (following an at sign).
	*
	* The resulting string is enclosed in angle brackets (< and >);
	*
	* @param hostName host name to be included in the message ID or
	* <code>null</code> if no host name should be included.
	* @return a new unique message identifier.
	*/
	public static String createUniqueMessageId(String hostName) {
	StringBuilder sb = new StringBuilder("<Mime4j.");
	sb.append(Integer.toHexString(nextCounterValue()));
	sb.append('.');
	sb.append(Long.toHexString(random.nextLong()));
	sb.append('.');
	sb.append(Long.toHexString(System.currentTimeMillis()));
	if (hostName != null) {
	sb.append('@');
	sb.append(hostName);
	}
	sb.append('>');
	return sb.toString();
	}

	/**
	* Formats the specified date into a RFC 822 date-time string.
	*
	* @param date
	* date to be formatted into a string.
	* @param zone
	* the time zone to use or <code>null</code> to use the default
	* time zone.
	* @return the formatted time string.
	*/
	public static String formatDate(Date date, TimeZone zone) {
	return RFC822_DATE_FORMAT
	.withZone(zone(zone))
	.format(date.toInstant());
	}

	private static ZoneId zone(TimeZone zone) {
	if (zone == null) {
	return TimeZone.getDefault().toZoneId();
	} else {
	return zone.toZoneId();
	}
	}

	/**
	* Splits the specified string into a multiple-line representation with
	* lines no longer than 76 characters (because the line might contain
	* encoded words; see <a href='http://www.faqs.org/rfcs/rfc2047.html'>RFC
	* 2047</a> section 2). If the string contains non-whitespace sequences
	* longer than 76 characters a line break is inserted at the whitespace
	* character following the sequence resulting in a line longer than 76
	* characters.
	*
	* @param s
	* string to split.
	* @param usedCharacters
	* number of characters already used up. Usually the number of
	* characters for header field name plus colon and one space.
	* @return a multiple-line representation of the given string.
	*/
	public static String fold(String s, int usedCharacters) {
	final int maxCharacters = 76;

	final int length = s.length();
	if (usedCharacters + length <= maxCharacters)
	return s;

	StringBuilder sb = new StringBuilder();

	int lastLineBreak = -usedCharacters;
	int wspIdx = indexOfWsp(s, 0);
	while (true) {
	if (wspIdx == length) {
	sb.append(s.substring(Math.max(0, lastLineBreak)));
	return sb.toString();
	}

	int nextWspIdx = indexOfWsp(s, wspIdx + 1);

	if (nextWspIdx - lastLineBreak > maxCharacters) {
	sb.append(s, Math.max(0, lastLineBreak), wspIdx);
	sb.append("\r\n");
	lastLineBreak = wspIdx;
	}

	wspIdx = nextWspIdx;
	}
	}

	/**
	* Unfold a multiple-line representation into a single line.
	*
	* @param s
	* string to unfold.
	* @return unfolded string.
	*/
	public static String unfold(String s) {
	final int length = s.length();
	for (int idx = 0; idx < length; idx++) {
	char c = s.charAt(idx);
	if (c == '\r' \|\| c == '\n') {
	return unfold0(s, idx);
	}
	}

	return s;
	}

	/**
	Unfold and decode header value
	*/
	public static String unscrambleHeaderValue(String headerValue) {
	return DecoderUtil.decodeEncodedWords(
	MimeUtil.unfold(headerValue),
	DecodeMonitor.SILENT);
	}

	private static String unfold0(String s, int crlfIdx) {
	final int length = s.length();
	StringBuilder sb = new StringBuilder(length);

	if (crlfIdx > 0) {
	sb.append(s, 0, crlfIdx);
	}

	int lastLineBreak = crlfIdx;
	for (int idx = crlfIdx + 1; idx < length; idx++) {
	char c = s.charAt(idx);
	if (c == '\r' \|\| c == '\n') {
	if (idx > lastLineBreak + 1) {
	sb.append(s, lastLineBreak + 1, idx);
	}
	lastLineBreak = idx;
	}
	}
	if (lastLineBreak < s.length() - 1 && s.length() > 0) {
	sb.append(s, lastLineBreak + 1, s.length());
	}

	return sb.toString();
	}

	private static int indexOfWsp(String s, int fromIndex) {
	final int len = s.length();
	for (int index = fromIndex; index < len; index++) {
	char c = s.charAt(index);
	if (c == ' ' \|\| c == '\t')
	return index;
	}
	return len;
	}

	private static synchronized int nextCounterValue() {
	return counter++;
	}

	private static final int INITIAL_YEAR = 1970;
	public static final DateTimeFormatter RFC822_DATE_FORMAT = new DateTimeFormatterBuilder()
	.parseCaseInsensitive()
	.parseLenient()
	.appendText(DAY_OF_WEEK, dayOfWeek())
	.appendLiteral(", ")
	.appendValue(DAY_OF_MONTH, 1, 2, SignStyle.NOT_NEGATIVE)
	.appendLiteral(' ')
	.appendText(MONTH_OF_YEAR, monthOfYear())
	.appendLiteral(' ')
	.appendValueReduced(YEAR, 4, 4, INITIAL_YEAR)
	.appendLiteral(' ')
	.appendValue(HOUR_OF_DAY, 2)
	.appendLiteral(':')
	.appendValue(MINUTE_OF_HOUR, 2)
	.appendLiteral(':')
	.appendValue(SECOND_OF_MINUTE, 2)
	.appendLiteral(' ')
	.appendOffset("+HHMM", "+0000")
	.toFormatter()
	.withZone(TimeZone.getDefault().toZoneId())
	.withLocale(Locale.US);

	private static Map<Long, String> monthOfYear() {
	HashMap<Long, String> result = new HashMap<>();
	result.put(1L, "Jan");
	result.put(2L, "Feb");
	result.put(3L, "Mar");
	result.put(4L, "Apr");
	result.put(5L, "May");
	result.put(6L, "Jun");
	result.put(7L, "Jul");
	result.put(8L, "Aug");
	result.put(9L, "Sep");
	result.put(10L, "Oct");
	result.put(11L, "Nov");
	result.put(12L, "Dec");
	return result;
	}

	private static Map<Long, String> dayOfWeek() {
	HashMap<Long, String> result = new HashMap<>();
	result.put(1L, "Mon");
	result.put(2L, "Tue");
	result.put(3L, "Wed");
	result.put(4L, "Thu");
	result.put(5L, "Fri");
	result.put(6L, "Sat");
	result.put(7L, "Sun");
	return result;
	}
	}