maps.java

ZK 基础介绍 功能操作 模块 结合数据库操作

	parse(Map map, String src, char separator, char quote)
	throws IllegalSyntaxException {
		return parse(map, src, separator, quote, false);
	}
	/**
	 * Parses a string into a map.
	 *
	 * <p>If = is omitted, whether it is considered as a key with the null
	 * value or a value with the null key depends on
	 * the asValue argument. If true, it is considered as a value with
	 * the null key.
	 *
	 * <p>For example, if the following string is parsed with asValue=false:<br/>
	 * a12=12,b3,c6=abc=125,x=y
	 *
	 * <p>Then, a map with the following content is returned:<br/>
	 * ("a12", "12"), ("b3", null), ("c6", "abc=125"), ("x", "y")
	 *
	 * <p>Notice: only the first = after separator is meaningful,
	 * so you don't have to escape the following =.
	 * <p>Beside specifying the quote character, you could use back slash
	 * quote a single character (as Java does).
	 *
	 * @param map the map to put parsed results to; null to create a
	 * new hash map
	 * @param src the string to parse
	 * @param separator the separator, e.g., ' ' or ','.
	 * @param quote the quote character to surrounding value, e.g.,
	 * name = 'value'. If (char)0, no quotation is recognized.
	 * Notice: if value is an expression, it is better to specify (char)0
	 * because expression might contain strings.
	 * @param asValue whether to consider the substring without = as
	 * a value (with the null key), or as a key (with the null value)
	 * @return the map being generated
	 *
	 * @exception IllegalSyntaxException if syntax errors
	 * @see CollectionsX#parse
	 * @see #toString(Map, char, char)
	 * @since 2.4.0
	 */
	public static final Map 
	parse(Map map, String src, char separator, char quote, boolean asValue)
	throws IllegalSyntaxException {
		if (separator == (char)0)
			throw new IllegalArgumentException("Separator cannot be 0");
		if (map == null)
			map = new HashMap();
		if (src == null || src.length() == 0)
			return map; //nothing to do

		//prepare delimiters for keys and values.
		final String delimValue, delimKey;
		{	final StringBuffer delimsb =
				new StringBuffer().append(separator);
			if (quote != (char)0)
				delimsb.append(quote);
			delimValue = delimsb.toString();
			delimKey = delimsb.append('=').toString();
		}

		//parase
		for (int j = 0, len = src.length();;) {
			//handle name
			Token tk = next(src, delimKey, j, true);
//			if (D.ON && log.finerable()) log.finer("name: "+tk.token+" "+tk.cc);
			j = tk.next;
			final String name = tk.token;
			switch (tk.cc) {
			case '=':
				if (name.length() == 0)
					throw newIllegalSyntaxException(MCommon.UNEXPECTED_CHARACTER, tk.cc, src);
				++j; //skip =
				break;
			case (char)0:
//				assert tk.next >= len;
				if (name.length() > 0)
					if (asValue) map.put(null, name);
					else map.put(name, null);
				return map;//done
			default:
				//If separator is ' ', tk.cc can be anything; see next()
				if ((separator != ' ' && tk.cc != separator)
				|| name.length() == 0)
					throw newIllegalSyntaxException(MCommon.UNEXPECTED_CHARACTER, tk.cc, src);

				if (asValue) map.put(null, name);
				else map.put(name, null);
				if (tk.cc == separator)
					++j; //skip separator
				continue;
			}

			//handle value
			tk = next(src, delimValue, j, false);
//			if (D.ON && log.finerable()) log.finer("value: "+tk.token+" "+tk.cc);
			j = tk.next;
			final String value = tk.token;
			if (quote != (char)0 && tk.cc == quote) {
				if (value.length() > 0)
					throw newIllegalSyntaxException(MCommon.UNEXPECTED_CHARACTER, tk.cc, src);

				final StringBuffer valsb = new StringBuffer(32);
				for (;;) {
					if (++j == len)
						throw newIllegalSyntaxException(MCommon.EXPECTING_CHARACTER, tk.cc, src);

					final char cc = src.charAt(j);
					if (cc == tk.cc)
						break;
					valsb.append(cc == '\\' ? escape(src, ++j): cc);
				}
				map.put(name, valsb.toString());
				++j; //skip the closing ' or "
			} else {
				map.put(name, value);
			}

			if (separator != ' ') {
				//If not ' ', ensure the following is a separator
				j = Strings.skipWhitespaces(src, j);
				if (j >= len)
					return map;
				if (src.charAt(j) != separator)
					throw newIllegalSyntaxException(MCommon.EXPECTING_CHARACTER, separator, src);
				++j; //skip separator
			}
		}
	}
	private static final IllegalSyntaxException
	newIllegalSyntaxException(int code, char cc, String src) {
		return new IllegalSyntaxException(code, new Object[] {new Character(cc), src});
	}
	private static class Token {
		/** The next position right after token. */
		private final int next;
		/** The character before next. */
		private final char cc;
		/** The token before next. */
		private final String token;
		private Token(int next, char cc, String token) {
			this.next = next;
			this.cc = cc;
			this.token = token;
		}
	}
	private static final Token
	next(String src, String delimiters, int j, boolean whitespaceAware) {
		final StringBuffer tksb = new StringBuffer(64);
		final int len = src.length();
		j = Strings.skipWhitespaces(src, j);
		for (; j < len; ++j) {
			final char cc = src.charAt(j);
			if (cc == '\\') {
				tksb.append(escape(src, ++j));
			} else if (delimiters.indexOf(cc) >= 0) {
				//note: cc might be a separator which might be a whitespace
				j = Strings.skipWhitespaces(src, j);
				break; //done
			} else if (Character.isWhitespace(cc)) {
				final int k = Strings.skipWhitespaces(src, j);
				//done if the following is nothing but whitespace or...
				if (whitespaceAware || k >= len
				|| delimiters.indexOf(src.charAt(k))>=0) {
					j = k;
					break; //done
				}
				if (j > k - 1) { //more than one whitespaces
					tksb.append(src.substring(j, k));
					j = k - 1; //j will increase by one later
				} else {
					tksb.append(cc);
				}
			} else if (cc == (char)0) {
				throw newIllegalSyntaxException(MCommon.UNEXPECTED_CHARACTER, (char)0, src);
			} else {
				tksb.append(cc);
			}
		}
		return new Token(j, j < len ? src.charAt(j): (char)0, tksb.toString());
	}
	private static final char escape(String src, int j) {
		if (j >= src.length())
			throw new IllegalSyntaxException(MCommon.ILLEGAL_CHAR, "\\");
		final char cc = src.charAt(j);
		return cc == 'n' ? '\n': cc == 't' ? '\t': cc;
	}
	/**
	 * Converts a map to a string.
	 *
	 * @param map the map to convert from
	 * @param quote the quotation character; 0 means no quotation surrunding
	 * the value
	 * @param separator the separator between two name=value pairs
	 * @see #parse(Map, String, char, char)
	 */
	public static final String toString(Map map, char quote, char separator) {
		return toStringBuffer(new StringBuffer(64), map, quote, separator)
			.toString();
	}
	/** Converts a map to string and append to a string buffer.
	 * @see #toString
	 */
	public static final StringBuffer
	toStringBuffer(StringBuffer sb, Map map, char quote, char separator) {
		if (separator == (char)0)
			throw new IllegalArgumentException("Separator cannot be 0");
		if (map.isEmpty())
			return sb; //nothing to do

		//prepare characters to escape with backslash.
		final String escKey, escValue;
		{	final StringBuffer escsb = new StringBuffer(12)
				.append(",\\'\" \n\t").append(separator);
			if (quote != (char)0 && quote != '\'' && quote != '"')
				escsb.append(quote);
			escValue = escsb.toString();
			escKey = escsb.append('=').toString();
		}

		//convert one-by-one
		for (final Iterator it = map.entrySet().iterator();
		it.hasNext();) {
			final Map.Entry me = (Map.Entry)it.next();

			final Object key = me.getKey();
			if (key == null)
				throw new IllegalSyntaxException("Unable to encode null key: "+map);
			final String skey = key.toString();
			if (skey == null || skey.length() == 0)
				throw new IllegalSyntaxException(MCommon.EMPTY_NOT_ALLOWED, "key");
			encode(sb, skey, escKey);

			final Object val = me.getValue();
			if (val != null) {
				sb.append('=');
				if (quote != (char)0)
					sb.append(quote);
				encode(sb, val.toString(), escValue);
				if (quote != (char)0)
					sb.append(quote);
			}
			sb.append(separator);
		}
		sb.setLength(sb.length() - 1); //remove the last comma
		return sb;
	}
	private static final void
	encode(StringBuffer sb, String val, String escapes) {
		for (int j = 0, len = val.length();;) {
			final int k = Strings.anyOf(val, escapes, j);
			if (k >= len) {
				sb.append(val.substring(j));
				return;
			}
			sb.append(val.substring(j, k)).append('\\');
			final char cc = val.charAt(k);
			sb.append(cc == '\n' ? 'n': cc == '\t' ? 't': cc);
			j = k + 1;
		}
	}
}