Java tutorial
/**************************************************************** * 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 java.util.HashMap; import java.util.Map; import java.util.Random; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; /** * A utility class, which provides some MIME related application logic. */ public final class MimeUtil { private static final Log log = LogFactory.getLog(MimeUtil.class); /** * 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"; /** <code>MIME-Version</code> header name (lowercase) */ public static final String MIME_HEADER_MIME_VERSION = "mime-version"; /** <code>Content-ID</code> header name (lowercase) */ public static final String MIME_HEADER_CONTENT_ID = "content-id"; /** <code>Content-Description</code> header name (lowercase) */ public static final String MIME_HEADER_CONTENT_DESCRIPTION = "content-description"; /** * <code>Content-Disposition</code> header name (lowercase). * See <a href='http://www.faqs.org/rfcs/rfc2183.html'>RFC2183</a>. */ public static final String MIME_HEADER_CONTENT_DISPOSITION = "content-disposition"; /** * <code>Content-Disposition</code> filename parameter (lowercase). * See <a href='http://www.faqs.org/rfcs/rfc2183.html'>RFC2183</a>. */ public static final String PARAM_FILENAME = "filename"; /** * <code>Content-Disposition</code> modification-date parameter (lowercase). * See <a href='http://www.faqs.org/rfcs/rfc2183.html'>RFC2183</a>. */ public static final String PARAM_MODIFICATION_DATE = "modification-date"; /** * <code>Content-Disposition</code> creation-date parameter (lowercase). * See <a href='http://www.faqs.org/rfcs/rfc2183.html'>RFC2183</a>. */ public static final String PARAM_CREATION_DATE = "creation-date"; /** * <code>Content-Disposition</code> read-date parameter (lowercase). * See <a href='http://www.faqs.org/rfcs/rfc2183.html'>RFC2183</a>. */ public static final String PARAM_READ_DATE = "read-date"; /** * <code>Content-Disposition</code> size parameter (lowercase). * See <a href='http://www.faqs.org/rfcs/rfc2183.html'>RFC2183</a>. */ public static final String PARAM_SIZE = "size"; /** * <code>Content-Langauge</code> header (lower case). * See <a href='http://www.faqs.org/rfcs/rfc4646.html'>RFC4646</a>. */ public static final String MIME_HEADER_LANGAUGE = "content-language"; /** * <code>Content-Location</code> header (lower case). * See <a href='http://www.faqs.org/rfcs/rfc2557.html'>RFC2557</a>. */ public static final String MIME_HEADER_LOCATION = "content-location"; /** * <code>Content-MD5</code> header (lower case). * See <a href='http://www.faqs.org/rfcs/rfc1864.html'>RFC1864</a>. */ public static final String MIME_HEADER_MD5 = "content-md5"; // 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.equals(pTransferEncoding); } /** * <p>Parses a complex field value into a map of key/value pairs. You may * use this, for example, to parse a definition like * <pre> * text/plain; charset=UTF-8; boundary=foobar * </pre> * The above example would return a map with the keys "", "charset", * and "boundary", and the values "text/plain", "UTF-8", and "foobar". * </p><p> * Header value will be unfolded and excess white space trimmed. * </p> * @param pValue The field value to parse. * @return The result map; use the key "" to retrieve the first value. */ public static Map getHeaderParams(String pValue) { pValue = pValue.trim(); /* * Unfold Content-Type value */ CharArrayBuffer sb = new CharArrayBuffer(128); for (int i = 0; i < pValue.length(); i++) { char c = pValue.charAt(i); if (c == '\r' || c == '\n') { continue; } sb.append(c); } pValue = sb.toString(); Map result = new HashMap(); // split main value and parameters String main; String rest; if (pValue.indexOf(";") == -1) { main = pValue; rest = null; } else { main = pValue.substring(0, pValue.indexOf(";")); rest = pValue.substring(main.length() + 1); } result.put("", main); if (rest != null) { char[] chars = rest.toCharArray(); CharArrayBuffer paramName = new CharArrayBuffer(64); CharArrayBuffer paramValue = new CharArrayBuffer(64); final byte READY_FOR_NAME = 0; final byte IN_NAME = 1; final byte READY_FOR_VALUE = 2; final byte IN_VALUE = 3; final byte IN_QUOTED_VALUE = 4; final byte VALUE_DONE = 5; final byte ERROR = 99; byte state = READY_FOR_NAME; boolean escaped = false; for (int i = 0; i < chars.length; i++) { char c = chars[i]; switch (state) { case ERROR: if (c == ';') state = READY_FOR_NAME; break; case READY_FOR_NAME: if (c == '=') { log.error("Expected header param name, got '='"); state = ERROR; break; } paramName = new CharArrayBuffer(64); paramValue = new CharArrayBuffer(64); state = IN_NAME; // fall-through case IN_NAME: if (c == '=') { if (paramName.length() == 0) state = ERROR; else state = READY_FOR_VALUE; break; } // not '='... just add to name paramName.append(c); break; case READY_FOR_VALUE: boolean fallThrough = false; switch (c) { case ' ': case '\t': break; // ignore spaces, especially before '"' case '"': state = IN_QUOTED_VALUE; break; default: state = IN_VALUE; fallThrough = true; break; } if (!fallThrough) break; // fall-through case IN_VALUE: fallThrough = false; switch (c) { case ';': case ' ': case '\t': result.put(paramName.toString().trim().toLowerCase(), paramValue.toString().trim()); state = VALUE_DONE; fallThrough = true; break; default: paramValue.append(c); break; } if (!fallThrough) break; case VALUE_DONE: switch (c) { case ';': state = READY_FOR_NAME; break; case ' ': case '\t': break; default: state = ERROR; break; } break; case IN_QUOTED_VALUE: switch (c) { case '"': if (!escaped) { // don't trim quoted strings; the spaces could be intentional. result.put(paramName.toString().trim().toLowerCase(), paramValue.toString()); state = VALUE_DONE; } else { escaped = false; paramValue.append(c); } break; case '\\': if (escaped) { paramValue.append('\\'); } escaped = !escaped; break; default: if (escaped) { paramValue.append('\\'); } escaped = false; paramValue.append(c); break; } break; } } // done looping. check if anything is left over. if (state == IN_VALUE) { result.put(paramName.toString().trim().toLowerCase(), paramValue.toString().trim()); } } return result; } /** * 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. */ public static String createUniqueBoundary() { StringBuffer sb = new StringBuffer(); 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) { StringBuffer sb = new StringBuffer("<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(); } private static synchronized int nextCounterValue() { return counter++; } }