Java tutorial
/** * HeaderFramework * Copyright 2004 by Michael Peter Christen, mc@yacy.net, Frankfurt a. M., Germany * First released 2004 at http://yacy.net * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public License * along with this program in the file lgpl21.txt * If not, see <http://www.gnu.org/licenses/>. */ package net.yacy.cora.protocol; import java.io.BufferedReader; import java.io.File; import java.io.FileOutputStream; import java.io.IOException; import java.text.ParseException; import java.text.SimpleDateFormat; import java.util.Calendar; import java.util.Date; import java.util.Iterator; import java.util.Locale; import java.util.Map; import java.util.TimeZone; import java.util.TreeMap; import java.util.concurrent.ConcurrentHashMap; import net.yacy.cora.document.encoding.ASCII; import net.yacy.cora.document.encoding.UTF8; import net.yacy.cora.util.CommonPattern; import net.yacy.cora.util.ConcurrentLog; /** * this class implements a key-value mapping, as a hashtable * The difference to ordinary hashtable implementations is that the * keys are not compared by the equal() method, but are always * treated as string and compared as * key.uppercase().equal(.uppercase(comparator)) */ public class HeaderFramework extends TreeMap<String, String> implements Map<String, String> { private static final long serialVersionUID = 18L; /* ============================================================= * Constants defining http versions * ============================================================= */ public static final String HTTP_VERSION_0_9 = "HTTP/0.9"; public static final String HTTP_VERSION_1_0 = "HTTP/1.0"; public static final String HTTP_VERSION_1_1 = "HTTP/1.1"; /* ============================================================= * Constants defining http header names * ============================================================= */ public static final String HOST = "Host"; public static final String USER_AGENT = "User-Agent"; public static final String ACCEPT = "Accept"; public static final String ACCEPT_LANGUAGE = "Accept-Language"; public static final String ACCEPT_ENCODING = "Accept-Encoding"; public static final String ACCEPT_CHARSET = "Accept-Charset"; public static final String CONTENT_LENGTH = "Content-Length"; public static final String CONTENT_TYPE = "Content-Type"; public static final String CONTENT_MD5 = "Content-MD5"; public static final String CONTENT_LOCATION = "Content-Location"; public static final String CONTENT_ENCODING = "Content-Encoding"; public static final String TRANSFER_ENCODING = "Transfer-Encoding"; public static final String PRAGMA = "Pragma"; public static final String CACHE_CONTROL = "Cache-Control"; public static final String DATE = "Date"; // time message/response was created, https://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.18 public static final String LAST_MODIFIED = "Last-Modified"; public static final String SERVER = "Server"; public static final String ACCEPT_RANGES = "Accept-Ranges"; public static final String CONTENT_RANGE = "Content-Range"; public static final String RANGE = "Range"; public static final String LOCATION = "Location"; public static final String ETAG = "ETag"; public static final String VIA = "Via"; public static final String X_FORWARDED_FOR = "X-Forwarded-For"; public static final String X_ROBOTS_TAG = "X-Robots-Tag"; // see http://googleblog.blogspot.com/2007/07/robots-exclusion-protocol-now-with-even.html public static final String X_ROBOTS = "X-Robots"; public static final String X_YACY_INDEX_CONTROL = "X-YaCy-Index-Control"; /** Added when generating legacy request header to allow template servlets to know the original request scheme : "http" or "https" */ public static final String X_YACY_REQUEST_SCHEME = "X-YaCy-Request-Scheme"; // TODO: after completing implementation of HttpServletRequest getScheme() should be used and this can be removed public static final String SET_COOKIE = "Set-Cookie"; public static final String SET_COOKIE2 = "Set-Cookie2"; public static final String EXPIRES = "Expires"; public static final String CORS_ALLOW_ORIGIN = "Access-Control-Allow-Origin"; // Cross-Origin Resource Sharing properties (http://www.w3.org/TR/cors/) public static final String RESPONSE_TIME_MILLIS = "ResponseTimeMillis"; /* ============================================================= * Constants for content-encodings * ============================================================= */ public static final String CONTENT_ENCODING_GZIP = "gzip"; /* ============================================================= * Constants defining http methods * ============================================================= */ public static final String METHOD_GET = "GET"; public static final String METHOD_HEAD = "HEAD"; public static final String METHOD_POST = "POST"; public static final String METHOD_CONNECT = "CONNECT"; /* * constanst for metadata which is stored in the ResponseHeader */ public static final String STATUS_CODE = "STATUS_CODE"; /* ============================================================= * defining default http status messages * ============================================================= */ public static final Map<String, String> http1_0 = new ConcurrentHashMap<String, String>(); static { http1_0.put("200", "OK"); http1_0.put("201", "Created"); http1_0.put("202", "Accepted"); http1_0.put("204", "No Content"); http1_0.put("300", "Multiple Choices"); http1_0.put("301", "Moved Permanently"); http1_0.put("302", "Moved Temporarily"); http1_0.put("304", "Not Modified"); http1_0.put("400", "Bad Request"); http1_0.put("401", "Unauthorized"); http1_0.put("403", "Forbidden"); http1_0.put("404", "Not Found"); http1_0.put("500", "Internal Server Error"); http1_0.put("501", "Not Implemented"); http1_0.put("502", "Bad Gateway"); http1_0.put("503", "Service Unavailable"); } public static final Map<String, String> http1_1 = new ConcurrentHashMap<String, String>(); static { http1_1.putAll(http1_0); http1_1.put("100", "Continue"); http1_1.put("101", "Switching Protocols"); http1_1.put("203", "Non-Authoritative Information"); http1_1.put("205", "Reset Content"); http1_1.put("206", "Partial Content"); http1_1.put("300", "Multiple Choices"); http1_1.put("303", "See Other"); http1_1.put("305", "Use Proxy"); http1_1.put("307", "Temporary Redirect"); http1_1.put("402", "Payment Required"); http1_1.put("405", "Method Not Allowed"); http1_1.put("406", "Not Acceptable"); http1_1.put("407", "Proxy Authentication Required"); http1_1.put("408", "Request Time-out"); http1_1.put("409", "Conflict"); http1_1.put("410", "Gone"); http1_1.put("411", "Length Required"); http1_1.put("412", "Precondition Failed"); http1_1.put("413", "Request Entity Too Large"); http1_1.put("414", "Request-URI Too Large"); http1_1.put("415", "Unsupported Media Type"); http1_1.put("416", "Requested range not satisfiable"); http1_1.put("417", "Expectation Failed"); http1_1.put("504", "Gateway Time-out"); http1_1.put("505", "HTTP Version not supported"); } /* PROPERTIES: General properties */ // Properties are used to internally store or remember header values and additional connection information // One of the usages is in proxy operation to prepare header values to be set as header values upon connection // * use of properties as header values is discouraged (e.g. as proxy transmits it as arbitrary headers) [2016-8-21] public static final String CONNECTION_PROP_HTTP_VER = "HTTP"; public static final String CONNECTION_PROP_PROTOCOL = "PROTOCOL"; public static final String CONNECTION_PROP_HOST = "HOST"; public static final String CONNECTION_PROP_USER = "USER"; public static final String CONNECTION_PROP_METHOD = "METHOD"; public static final String CONNECTION_PROP_PATH = "PATH"; public static final String CONNECTION_PROP_EXT = "EXT"; // public static final String CONNECTION_PROP_ARGS = "ARGS"; // use getQueryString() or getParameter() public static final String CONNECTION_PROP_CLIENTIP = "CLIENTIP"; public static final String CONNECTION_PROP_PERSISTENT = "PERSISTENT"; public static final String CONNECTION_PROP_REQUEST_START = "REQUEST_START"; public static final String CONNECTION_PROP_REQUEST_END = "REQUEST_END"; /* PROPERTIES: Client -> Proxy */ public static final String CONNECTION_PROP_DIGESTURL = "URL"; // value DigestURL object public static final String CONNECTION_PROP_CLIENT_HTTPSERVLETREQUEST = "CLIENT_HTTPSERVLETREQUEST"; /* PROPERTIES: Proxy -> Client */ public static final String CONNECTION_PROP_PROXY_RESPOND_CODE = "PROXY_RESPOND_CODE"; public static final String CONNECTION_PROP_PROXY_RESPOND_STATUS = "PROXY_RESPOND_STATUS"; public static final String CONNECTION_PROP_PROXY_RESPOND_HEADER = "PROXY_RESPOND_HEADER"; public static final String CONNECTION_PROP_PROXY_RESPOND_SIZE = "PROXY_REQUEST_SIZE"; public HeaderFramework() { super(ASCII.insensitiveASCIIComparator); } public HeaderFramework(final Map<String, String> othermap) { // creates a case insensitive map from another map super(ASCII.insensitiveASCIIComparator); // load with data if (othermap != null) putAll(othermap); } /** Date formatter/parser for standard compliant HTTP header dates (RFC 1123) */ private static final String PATTERN_RFC1123 = "EEE, dd MMM yyyy HH:mm:ss Z"; // with numeric time zone indicator as defined in RFC5322 private static final String PATTERN_RFC1036 = "EEEE, dd-MMM-yy HH:mm:ss zzz"; private static final String PATTERN_ANSIC = "EEE MMM d HH:mm:ss yyyy"; public static final SimpleDateFormat FORMAT_RFC1123 = new SimpleDateFormat(PATTERN_RFC1123, Locale.US); public static final SimpleDateFormat FORMAT_RFC1036 = new SimpleDateFormat(PATTERN_RFC1036, Locale.US); public static final SimpleDateFormat FORMAT_ANSIC = new SimpleDateFormat(PATTERN_ANSIC, Locale.US); private static final TimeZone TZ_GMT = TimeZone.getTimeZone("GMT"); private static final Calendar CAL_GMT = Calendar.getInstance(TZ_GMT, Locale.US); /** * RFC 2616 requires that HTTP clients are able to parse all 3 different * formats. All times MUST be in GMT/UTC, but ... */ private static final SimpleDateFormat[] FORMATS_HTTP = new SimpleDateFormat[] { // RFC 1123/822 (Standard) "Mon, 12 Nov 2007 10:11:12 GMT" FORMAT_RFC1123, // RFC 1036/850 (old) "Monday, 12-Nov-07 10:11:12 GMT" FORMAT_RFC1036, // ANSI C asctime() "Mon Nov 12 10:11:12 2007" FORMAT_ANSIC, }; private static long lastRFC1123long = 0; private static String lastRFC1123string = ""; public static final String formatRFC1123(final Date date) { if (date == null) return ""; if (Math.abs(date.getTime() - lastRFC1123long) < 1000) { //System.out.println("date cache hit - " + lastRFC1123string); return lastRFC1123string; } synchronized (FORMAT_RFC1123) { final String s = FORMAT_RFC1123.format(date); lastRFC1123long = date.getTime(); lastRFC1123string = s; return s; } } /** Initialization of static formats */ static { // 2-digit dates are automatically parsed by SimpleDateFormat, // we need to detect the real year by adding 1900 or 2000 to // the year value starting with 1970 CAL_GMT.setTimeInMillis(0); for (final SimpleDateFormat format : FORMATS_HTTP) { format.setTimeZone(TZ_GMT); format.set2DigitYearStart(CAL_GMT.getTime()); } } /** * Parse a HTTP string representation of a date into a Date instance. * @param s The date String to parse. * @return The Date instance if successful, <code>null</code> otherwise. */ public static Date parseHTTPDate(String s) { s = s.trim(); if (s == null || s.length() < 9) return null; for (final SimpleDateFormat format : FORMATS_HTTP) synchronized (format) { try { return format.parse(s); } catch (final ParseException e) { } } return null; } // to make the occurrence of multiple keys possible, we add them using a counter public String add(final String key, final String value) { final int c = keyCount(key); if (c == 0) return put(key, value); return put("*" + key + "-" + Integer.toString(c), value); } /** * Count occurence of header keys, look for original header name and a * numbered version of the header *headername-NUMBER , with NUMBER starting at 1 * @param key the raw header name * @return number of headers with same name */ public int keyCount(final String key) { if (!(containsKey(key))) return 0; int c = 1; final String h = "*" + key + "-"; while (containsKey(h + Integer.toString(c))) c++; return c; } // a convenience method to access the map with fail-over defaults public String get(final String key, final String dflt) { final String result = get(key); if (result == null) return dflt; return result; } /** * Get one Header of headers with same name. * The headers are internally numbered * @param key the raw header name * @param count the number of the numbered header name (0 = same as get(key)) * @return value of header with number=count */ public String getSingle(final String key, final int count) { if (count == 0) return get(key); // first look for just the key return get("*" + key + "-" + count); // now for the numbered header names } /** * Get multiple header values with same header name. * The header names are internally numbered (format *key-1) * @param key the raw header name * @return header values */ public String[] getMultiple(final String key) { final int count = keyCount(key); final String[] result = new String[count]; for (int i = 0; i < count; i++) result[i] = getSingle(key, i); return result; } // convenience methods for storing and loading to a file system public void store(final File f) throws IOException { FileOutputStream fos = null; try { fos = new FileOutputStream(f); for (final java.util.Map.Entry<String, String> entry : entrySet()) { fos.write(UTF8.getBytes(entry.getKey() + "=" + entry.getValue() + "\r\n")); } fos.flush(); } finally { if (fos != null) try { fos.close(); } catch (final Exception e) { } } } @Override public String toString() { return super.toString(); } /* * example header Connection=close Content-Encoding=gzip Content-Length=7281 Content-Type=text/html; charset=UTF-8 Date=Mon, 05 Jan 2004 11:55:10 GMT Server=Apache/1.3.26 */ /** * Get mime type from header field content-type * stripps any parameter (denoted by ';' see RFC 2616) * @return mime or on missing header field "application/octet-stream" */ public String mime() { final String tmpstr = this.get(CONTENT_TYPE, "application/octet-stream"); final int pos = tmpstr.indexOf(';'); if (pos > 0) { return tmpstr.substring(0, pos).trim(); } else { return tmpstr; } } /* * (non-Javadoc) * * @see * org.apache.commons.fileupload.RequestContext#getCharacterEncoding() */ public String getCharacterEncoding() { final String mimeType = getContentType(); if (mimeType == null) return null; final String[] parts = CommonPattern.SEMICOLON.split(mimeType); if (parts == null || parts.length <= 1) return null; for (int i = 1; i < parts.length; i++) { final String param = parts[i].trim(); if (param.startsWith("charset=")) { String charset = param.substring("charset=".length()).trim(); if (charset.length() > 0 && (charset.charAt(0) == '\"' || charset.charAt(0) == '\'')) charset = charset.substring(1); if (charset.endsWith("\"") || charset.endsWith("'")) charset = charset.substring(0, charset.length() - 1); return charset.trim(); } } return null; } /* * (non-Javadoc) * * @see org.apache.commons.fileupload.RequestContext#getContentLength() */ public int getContentLength() { if (containsKey(CONTENT_LENGTH)) { try { return (int) Long.parseLong(get(CONTENT_LENGTH)); } catch (final NumberFormatException e) { ConcurrentLog.warn("HeaderFramework", "content-length cannot be parsed: " + get(CONTENT_LENGTH)); return -1; } } return -1; } /* * provide method, which can handle big filelengths (for example from ftp) * because we can't change the interface in apache httpclient * * @see org.apache.commons.fileupload.RequestContext#getContentLength() */ public long getContentLengthLong() { if (containsKey(CONTENT_LENGTH)) { try { return Long.parseLong(get(CONTENT_LENGTH)); } catch (final NumberFormatException e) { return -1; } } return -1; } /** * Get header field content-type (unmodified) * which may include additional parameter (RFC 2616) * see also mime() * @see org.apache.commons.fileupload.RequestContext#getContentType() */ public String getContentType() { return this.get(CONTENT_TYPE); } protected Date headerDate(final String kind) { if (containsKey(kind)) { Date parsedDate = parseHTTPDate(get(kind)); if (parsedDate == null) return null; return parsedDate; } return null; } public StringBuilder toHeaderString(final String httpVersion, final int httpStatusCode, final String httpStatusText) { // creating a new buffer to store the header as string final StringBuilder theHeader = new StringBuilder(180); // generating the header string this.toHeaderString(httpVersion, httpStatusCode, httpStatusText, theHeader); // returning the result return theHeader; } public void toHeaderString(String httpVersion, final int httpStatusCode, String httpStatusText, final StringBuilder theHeader) { if (theHeader == null) throw new IllegalArgumentException(); // setting the http version if it was not already set if (httpVersion == null) httpVersion = HTTP_VERSION_1_0; // setting the status text if it was not already set if ((httpStatusText == null) || (httpStatusText.length() == 0)) { // http1_1 contains all status code text if (HeaderFramework.http1_1.containsKey(Integer.toString(httpStatusCode))) httpStatusText = HeaderFramework.http1_1.get(Integer.toString(httpStatusCode)); else httpStatusText = "Unknown"; } // write status line theHeader.append(httpVersion).append(" ").append(Integer.toString(httpStatusCode)).append(" ") .append(httpStatusText).append("\r\n"); // write header final Iterator<String> i = keySet().iterator(); String key; char tag; int count; while (i.hasNext()) { key = i.next(); tag = key.charAt(0); if ((tag != '*') && (tag != '#')) { // '#' in key is reserved for proxy attributes as artificial header values count = keyCount(key); for (int j = 0; j < count; j++) { theHeader.append(key).append(": ").append(getSingle(key, j)).append("\r\n"); } } } // end header theHeader.append("\r\n"); } /** * Reading http headers from a reader class and building up a httpHeader object * @param reader the {@link BufferedReader} that is used to read the http header lines * @return a {@link HeaderFramework}-Object containing all parsed headers * @throws IOException */ public void readHttpHeader(final BufferedReader reader) throws IOException { // reading all request headers int p; String line; while ((line = reader.readLine()) != null) { if (line.isEmpty()) break; if ((p = line.indexOf(':')) >= 0) { // store a property add(line.substring(0, p).trim(), line.substring(p + 1).trim()); } } } }