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A driver for Apache Cassandra 1.2+ that works exclusively with the Cassandra Query Language version 3
(CQL3) and Cassandra's binary protocol.
/*
* Copyright DataStax, Inc.
*
* Licensed 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 com.datastax.driver.core;
import java.text.ParseException;
import java.text.ParsePosition;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.TimeZone;
import java.util.concurrent.TimeUnit;
/**
* Simple utility class used to help parsing CQL values (mainly UDT and collection ones).
*/
public abstract class ParseUtils {
/**
* Valid ISO-8601 patterns for CQL timestamp literals.
*/
private static final String[] iso8601Patterns = new String[]{
"yyyy-MM-dd HH:mm",
"yyyy-MM-dd HH:mm:ss",
"yyyy-MM-dd HH:mmZ",
"yyyy-MM-dd HH:mm:ssZ",
"yyyy-MM-dd HH:mm:ss.SSS",
"yyyy-MM-dd HH:mm:ss.SSSZ",
"yyyy-MM-dd'T'HH:mm",
"yyyy-MM-dd'T'HH:mmZ",
"yyyy-MM-dd'T'HH:mm:ss",
"yyyy-MM-dd'T'HH:mm:ssZ",
"yyyy-MM-dd'T'HH:mm:ss.SSS",
"yyyy-MM-dd'T'HH:mm:ss.SSSZ",
"yyyy-MM-dd",
"yyyy-MM-ddZ"
};
/**
* Returns the index of the first character in toParse from idx that is not a "space".
*
* @param toParse the string to skip space on.
* @param idx the index to start skipping space from.
* @return the index of the first character in toParse from idx that is not a "space.
*/
public static int skipSpaces(String toParse, int idx) {
while (isBlank(toParse.charAt(idx)) && idx < toParse.length())
++idx;
return idx;
}
/**
* Assuming that idx points to the beginning of a CQL value in toParse, returns the
* index of the first character after this value.
*
* @param toParse the string to skip a value form.
* @param idx the index to start parsing a value from.
* @return the index ending the CQL value starting at {@code idx}.
* @throws IllegalArgumentException if idx doesn't point to the start of a valid CQL
* value.
*/
public static int skipCQLValue(String toParse, int idx) {
if (idx >= toParse.length())
throw new IllegalArgumentException();
if (isBlank(toParse.charAt(idx)))
throw new IllegalArgumentException();
int cbrackets = 0;
int sbrackets = 0;
int parens = 0;
boolean inString = false;
do {
char c = toParse.charAt(idx);
if (inString) {
if (c == '\'') {
if (idx + 1 < toParse.length() && toParse.charAt(idx + 1) == '\'') {
++idx; // this is an escaped quote, skip it
} else {
inString = false;
if (cbrackets == 0 && sbrackets == 0 && parens == 0)
return idx + 1;
}
}
// Skip any other character
} else if (c == '\'') {
inString = true;
} else if (c == '{') {
++cbrackets;
} else if (c == '[') {
++sbrackets;
} else if (c == '(') {
++parens;
} else if (c == '}') {
if (cbrackets == 0)
return idx;
--cbrackets;
if (cbrackets == 0 && sbrackets == 0 && parens == 0)
return idx + 1;
} else if (c == ']') {
if (sbrackets == 0)
return idx;
--sbrackets;
if (cbrackets == 0 && sbrackets == 0 && parens == 0)
return idx + 1;
} else if (c == ')') {
if (parens == 0)
return idx;
--parens;
if (cbrackets == 0 && sbrackets == 0 && parens == 0)
return idx + 1;
} else if (isBlank(c) || !isIdentifierChar(c)) {
if (cbrackets == 0 && sbrackets == 0 && parens == 0)
return idx;
}
} while (++idx < toParse.length());
if (inString || cbrackets != 0 || sbrackets != 0 || parens != 0)
throw new IllegalArgumentException();
return idx;
}
/**
* Assuming that idx points to the beginning of a CQL identifier in toParse, returns the
* index of the first character after this identifier.
*
* @param toParse the string to skip an identifier from.
* @param idx the index to start parsing an identifier from.
* @return the index ending the CQL identifier starting at {@code idx}.
* @throws IllegalArgumentException if idx doesn't point to the start of a valid CQL
* identifier.
*/
public static int skipCQLId(String toParse, int idx) {
if (idx >= toParse.length())
throw new IllegalArgumentException();
char c = toParse.charAt(idx);
if (isIdentifierChar(c)) {
while (idx < toParse.length() && isIdentifierChar(toParse.charAt(idx)))
idx++;
return idx;
}
if (c != '"')
throw new IllegalArgumentException();
while (++idx < toParse.length()) {
c = toParse.charAt(idx);
if (c != '"')
continue;
if (idx + 1 < toParse.length() && toParse.charAt(idx + 1) == '\"')
++idx; // this is an escaped double quote, skip it
else
return idx + 1;
}
throw new IllegalArgumentException();
}
/**
* Return {@code true} if the given character
* is allowed in a CQL identifier, that is,
* if it is in the range: {@code [0..9a..zA..Z-+._&]}.
*
* @param c The character to inspect.
* @return {@code true} if the given character
* is allowed in a CQL identifier, {@code false} otherwise.
*/
public static boolean isIdentifierChar(int c) {
return (c >= '0' && c <= '9')
|| (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z')
|| c == '-' || c == '+' || c == '.' || c == '_' || c == '&';
}
/**
* Return {@code true} if the given character
* is a valid whitespace character in CQL, that is,
* if it is a regular space, a tabulation sign,
* or a new line sign.
*
* @param c The character to inspect.
* @return {@code true} if the given character
* is a valid whitespace character, {@code false} otherwise.
*/
public static boolean isBlank(int c) {
return c == ' ' || c == '\t' || c == '\n';
}
/**
* Check whether the given string corresponds
* to a valid CQL long literal.
* Long literals are composed solely by digits,
* but can have an optional leading minus sign.
*
* @param str The string to inspect.
* @return {@code true} if the given string corresponds
* to a valid CQL integer literal, {@code false} otherwise.
*/
public static boolean isLongLiteral(String str) {
if (str == null || str.isEmpty())
return false;
char[] chars = str.toCharArray();
for (int i = 0; i < chars.length; i++) {
char c = chars[i];
if ((c < '0' && (i != 0 || c != '-')) || c > '9')
return false;
}
return true;
}
/**
* Return {@code true} if the given string is surrounded
* by single quotes, and {@code false} otherwise.
*
* @param value The string to inspect.
* @return {@code true} if the given string is surrounded
* by single quotes, and {@code false} otherwise.
*/
public static boolean isQuoted(String value) {
return isQuoted(value, '\'');
}
/**
* Quote the given string; single quotes are escaped.
* If the given string is null, this method returns a quoted empty string ({@code ''}).
*
* @param value The value to quote.
* @return The quoted string.
*/
public static String quote(String value) {
return quote(value, '\'');
}
/**
* Unquote the given string if it is quoted; single quotes are unescaped.
* If the given string is not quoted, it is returned without any modification.
*
* @param value The string to unquote.
* @return The unquoted string.
*/
public static String unquote(String value) {
return unquote(value, '\'');
}
/**
* Return {@code true} if the given string is surrounded
* by double quotes, and {@code false} otherwise.
*
* @param value The string to inspect.
* @return {@code true} if the given string is surrounded
* by double quotes, and {@code false} otherwise.
*/
public static boolean isDoubleQuoted(String value) {
return isQuoted(value, '\"');
}
/**
* Double quote the given string; double quotes are escaped.
* If the given string is null, this method returns a quoted empty string ({@code ""}).
*
* @param value The value to double quote.
* @return The double quoted string.
*/
public static String doubleQuote(String value) {
return quote(value, '"');
}
/**
* Unquote the given string if it is double quoted; double quotes are unescaped.
* If the given string is not double quoted, it is returned without any modification.
*
* @param value The string to un-double quote.
* @return The un-double quoted string.
*/
public static String unDoubleQuote(String value) {
return unquote(value, '"');
}
/**
* Parse the given string as a date, using one of the accepted ISO-8601 date patterns.
*
* This method is adapted from Apache Commons {@code DateUtils.parseStrictly()} method (that is used Cassandra side
* to parse date strings)..
*
* @throws ParseException If the given string is not a valid ISO-8601 date.
* @see 'Working with timestamps' section of CQL specification
*/
public static Date parseDate(String str) throws ParseException {
SimpleDateFormat parser = new SimpleDateFormat();
parser.setLenient(false);
// set a default timezone for patterns that do not provide one
parser.setTimeZone(TimeZone.getTimeZone("UTC"));
// Java 6 has very limited support for ISO-8601 time zone formats,
// so we need to transform the string first
// so that accepted patterns are correctly handled,
// such as Z for UTC, or "+00:00" instead of "+0000".
// Note: we cannot use the X letter in the pattern
// because it has been introduced in Java 7.
str = str.replaceAll("(\\+|\\-)(\\d\\d):(\\d\\d)$", "$1$2$3");
str = str.replaceAll("Z$", "+0000");
ParsePosition pos = new ParsePosition(0);
for (String parsePattern : iso8601Patterns) {
parser.applyPattern(parsePattern);
pos.setIndex(0);
Date date = parser.parse(str, pos);
if (date != null && pos.getIndex() == str.length()) {
return date;
}
}
throw new ParseException("Unable to parse the date: " + str, -1);
}
/**
* Parse the given string as a date, using the supplied date pattern.
*
* This method is adapted from Apache Commons {@code DateUtils.parseStrictly()} method (that is used Cassandra side
* to parse date strings)..
*
* @throws ParseException If the given string cannot be parsed with the given pattern.
* @see 'Working with timestamps' section of CQL specification
*/
public static Date parseDate(String str, String pattern) throws ParseException {
SimpleDateFormat parser = new SimpleDateFormat();
parser.setLenient(false);
// set a default timezone for patterns that do not provide one
parser.setTimeZone(TimeZone.getTimeZone("UTC"));
// Java 6 has very limited support for ISO-8601 time zone formats,
// so we need to transform the string first
// so that accepted patterns are correctly handled,
// such as Z for UTC, or "+00:00" instead of "+0000".
// Note: we cannot use the X letter in the pattern
// because it has been introduced in Java 7.
str = str.replaceAll("(\\+|\\-)(\\d\\d):(\\d\\d)$", "$1$2$3");
str = str.replaceAll("Z$", "+0000");
ParsePosition pos = new ParsePosition(0);
parser.applyPattern(pattern);
pos.setIndex(0);
Date date = parser.parse(str, pos);
if (date != null && pos.getIndex() == str.length()) {
return date;
}
throw new ParseException("Unable to parse the date: " + str, -1);
}
/**
* Parse the given string as a time, using the following time pattern: {@code hh:mm:ss[.fffffffff]}.
*
* This method is loosely based on {@code java.sql.Timestamp}.
*
* @param str The string to parse.
* @return A long value representing the number of nanoseconds since midnight.
* @throws ParseException if the string cannot be parsed.
* @see 'Working with time' section of CQL specification
*/
public static long parseTime(String str) throws ParseException {
String nanos_s;
long hour;
long minute;
long second;
long a_nanos = 0;
String formatError = "Timestamp format must be hh:mm:ss[.fffffffff]";
String zeros = "000000000";
if (str == null)
throw new IllegalArgumentException(formatError);
str = str.trim();
// Parse the time
int firstColon = str.indexOf(':');
int secondColon = str.indexOf(':', firstColon + 1);
// Convert the time; default missing nanos
if (firstColon > 0 && secondColon > 0 && secondColon < str.length() - 1) {
int period = str.indexOf('.', secondColon + 1);
hour = Integer.parseInt(str.substring(0, firstColon));
if (hour < 0 || hour >= 24)
throw new IllegalArgumentException("Hour out of bounds.");
minute = Integer.parseInt(str.substring(firstColon + 1, secondColon));
if (minute < 0 || minute >= 60)
throw new IllegalArgumentException("Minute out of bounds.");
if (period > 0 && period < str.length() - 1) {
second = Integer.parseInt(str.substring(secondColon + 1, period));
if (second < 0 || second >= 60)
throw new IllegalArgumentException("Second out of bounds.");
nanos_s = str.substring(period + 1);
if (nanos_s.length() > 9)
throw new IllegalArgumentException(formatError);
if (!Character.isDigit(nanos_s.charAt(0)))
throw new IllegalArgumentException(formatError);
nanos_s = nanos_s + zeros.substring(0, 9 - nanos_s.length());
a_nanos = Integer.parseInt(nanos_s);
} else if (period > 0)
throw new ParseException(formatError, -1);
else {
second = Integer.parseInt(str.substring(secondColon + 1));
if (second < 0 || second >= 60)
throw new ParseException("Second out of bounds.", -1);
}
} else
throw new ParseException(formatError, -1);
long rawTime = 0;
rawTime += TimeUnit.HOURS.toNanos(hour);
rawTime += TimeUnit.MINUTES.toNanos(minute);
rawTime += TimeUnit.SECONDS.toNanos(second);
rawTime += a_nanos;
return rawTime;
}
/**
* Format the given long value as a CQL time literal, using the following time pattern: {@code hh:mm:ss[.fffffffff]}.
*
* @param value A long value representing the number of nanoseconds since midnight.
* @return The formatted value.
* @see 'Working with time' section of CQL specification
*/
public static String formatTime(long value) {
int nano = (int) (value % 1000000000);
value -= nano;
value /= 1000000000;
int seconds = (int) (value % 60);
value -= seconds;
value /= 60;
int minutes = (int) (value % 60);
value -= minutes;
value /= 60;
int hours = (int) (value % 24);
value -= hours;
value /= 24;
assert (value == 0);
StringBuilder sb = new StringBuilder();
leftPadZeros(hours, 2, sb);
sb.append(":");
leftPadZeros(minutes, 2, sb);
sb.append(":");
leftPadZeros(seconds, 2, sb);
sb.append(".");
leftPadZeros(nano, 9, sb);
return sb.toString();
}
/**
* Return {@code true} if the given string is surrounded
* by the quote character given, and {@code false} otherwise.
*
* @param value The string to inspect.
* @return {@code true} if the given string is surrounded
* by the quote character, and {@code false} otherwise.
*/
private static boolean isQuoted(String value, char quoteChar) {
return value != null && value.length() > 1
&& value.charAt(0) == quoteChar && value.charAt(value.length() - 1) == quoteChar;
}
/**
* @param quoteChar " or '
* @return A quoted empty string.
*/
private static String emptyQuoted(char quoteChar) {
// don't handle non quote characters, this is done so that these are interned and don't create
// repeated empty quoted strings.
assert quoteChar == '"' || quoteChar == '\'';
if (quoteChar == '"')
return "\"\"";
else
return "''";
}
/**
* Quotes text and escapes any existing quotes in the text.
* {@code String.replace()} is a bit too inefficient (see JAVA-67, JAVA-1262).
*
* @param text The text.
* @param quoteChar The character to use as a quote.
* @return The text with surrounded in quotes with all existing quotes escaped with (i.e. ' becomes '')
*/
private static String quote(String text, char quoteChar) {
if (text == null || text.isEmpty())
return emptyQuoted(quoteChar);
int nbMatch = 0;
int start = -1;
do {
start = text.indexOf(quoteChar, start + 1);
if (start != -1)
++nbMatch;
} while (start != -1);
// no quotes found that need to be escaped, simply surround in quotes and return.
if (nbMatch == 0)
return quoteChar + text + quoteChar;
// 2 for beginning and end quotes.
// length for original text
// nbMatch for escape characters to add to quotes to be escaped.
int newLength = 2 + text.length() + nbMatch;
char[] result = new char[newLength];
result[0] = quoteChar;
result[newLength - 1] = quoteChar;
int newIdx = 1;
for (int i = 0; i < text.length(); i++) {
char c = text.charAt(i);
if (c == quoteChar) {
// escape quote with another occurrence.
result[newIdx++] = c;
result[newIdx++] = c;
} else {
result[newIdx++] = c;
}
}
return new String(result);
}
/**
* Unquotes text and unescapes non surrounding quotes.
* {@code String.replace()} is a bit too inefficient (see JAVA-67, JAVA-1262).
*
* @param text The text
* @param quoteChar The character to use as a quote.
* @return The text with surrounding quotes removed and non surrounding quotes unescaped (i.e. '' becomes ')
*/
private static String unquote(String text, char quoteChar) {
if (!isQuoted(text, quoteChar))
return text;
if (text.length() == 2)
return "";
String search = emptyQuoted(quoteChar);
int nbMatch = 0;
int start = -1;
do {
start = text.indexOf(search, start + 2);
// ignore the second to last character occurrence, as the last character is a quote.
if (start != -1 && start != text.length() - 2)
++nbMatch;
} while (start != -1);
// no escaped quotes found, simply remove surrounding quotes and return.
if (nbMatch == 0)
return text.substring(1, text.length() - 1);
// length of the new string will be its current length - the number of occurrences.
int newLength = text.length() - nbMatch - 2;
char[] result = new char[newLength];
int newIdx = 0;
// track whenever a quoteChar is encountered and the previous character is not a quoteChar.
boolean firstFound = false;
for (int i = 1; i < text.length() - 1; i++) {
char c = text.charAt(i);
if (c == quoteChar) {
if (firstFound) {
// The previous character was a quoteChar, don't add this to result, this action in
// effect removes consecutive quotes.
firstFound = false;
} else {
// found a quoteChar and the previous character was not a quoteChar, include in result.
firstFound = true;
result[newIdx++] = c;
}
} else {
// non quoteChar encountered, include in result.
result[newIdx++] = c;
firstFound = false;
}
}
return new String(result);
}
private static void leftPadZeros(int value, int digits, StringBuilder sb) {
sb.append(String.format("%0" + digits + "d", value));
}
private ParseUtils() {
}
}