/*
* Copyright 2010-2016 Amazon.com, Inc. or its affiliates. All Rights Reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License").
* You may not use this file except in compliance with the License.
* A copy of the License is located at
*
* http://aws.amazon.com/apache2.0
*
* or in the "license" file accompanying this file. This file 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.amazonaws.services.simpledb.util;
import com.amazonaws.util.DateUtils;
import java.text.ParseException;
import java.util.Collection;
import java.util.Date;
/**
* Provides collection of static functions for conversion of various values into
* strings that may be compared lexicographically.
*/
public class SimpleDBUtils {
/**
* static value hardcoding date format used for conversation of Date into
* String
*/
private static String DATE_FORMAT = "yyyy-MM-dd'T'HH:mm:ss.SSSZ";
/**
* Encodes positive integer value into a string by zero-padding number up to
* the specified number of digits.
*
* @param number positive integer to be encoded
* @param maxNumDigits maximum number of digits in the largest value in the
* data set
* @return string representation of the zero-padded integer
*/
public static String encodeZeroPadding(int number, int maxNumDigits) {
String integerString = Integer.toString(number);
int numZeroes = maxNumDigits - integerString.length();
StringBuffer strBuffer = new StringBuffer(numZeroes + integerString.length());
for (int i = 0; i < numZeroes; i++) {
strBuffer.insert(i, '0');
}
strBuffer.append(integerString);
return strBuffer.toString();
}
/**
* Encodes positive long value into a string by zero-padding the value up to
* the specified number of digits.
*
* @param number positive long to be encoded
* @param maxNumDigits maximum number of digits in the largest value in the
* data set
* @return string representation of the zero-padded long
*/
public static String encodeZeroPadding(long number, int maxNumDigits) {
String longString = Long.toString(number);
int numZeroes = maxNumDigits - longString.length();
StringBuffer strBuffer = new StringBuffer(numZeroes + longString.length());
for (int i = 0; i < numZeroes; i++) {
strBuffer.insert(i, '0');
}
strBuffer.append(longString);
return strBuffer.toString();
}
/**
* Encodes positive float value into a string by zero-padding number up to
* the specified number of digits
*
* @param number positive float value to be encoded
* @param maxNumDigits maximum number of digits preceding the decimal point
* in the largest value in the data set
* @return string representation of the zero-padded float value
*/
public static String encodeZeroPadding(float number, int maxNumDigits) {
String floatString = Float.toString(number);
int numBeforeDecimal = floatString.indexOf('.');
numBeforeDecimal = (numBeforeDecimal >= 0 ? numBeforeDecimal : floatString.length());
int numZeroes = maxNumDigits - numBeforeDecimal;
StringBuffer strBuffer = new StringBuffer(numZeroes + floatString.length());
for (int i = 0; i < numZeroes; i++) {
strBuffer.insert(i, '0');
}
strBuffer.append(floatString);
return strBuffer.toString();
}
/**
* Decodes zero-padded positive integer value from the string representation
*
* @param value zero-padded string representation of the integer
* @return original integer value
*/
public static int decodeZeroPaddingInt(String value) {
return Integer.parseInt(value, 10);
}
/**
* Decodes a zero-padded positive long value from the string representation
*
* @param value zero-padded string representation of the long
* @return original long value
*/
public static long decodeZeroPaddingLong(String value) {
return Long.parseLong(value, 10);
}
/**
* Decodes zero-padded positive float value from the string representation
*
* @param value zero-padded string representation of the float value
* @return original float value
*/
public static float decodeZeroPaddingFloat(String value) {
return Float.valueOf(value).floatValue();
}
/**
* Encodes real integer value into a string by offsetting and zero-padding
* number up to the specified number of digits. Use this encoding method if
* the data range set includes both positive and negative values.
*
* @param number integer to be encoded
* @param maxNumDigits maximum number of digits in the largest absolute
* value in the data set
* @param offsetValue offset value, has to be greater than absolute value of
* any negative number in the data set.
* @return string representation of the integer
*/
public static String encodeRealNumberRange(int number, int maxNumDigits,
int offsetValue) {
long offsetNumber = number + offsetValue;
String longString = Long.toString(offsetNumber);
int numZeroes = maxNumDigits - longString.length();
StringBuffer strBuffer = new StringBuffer(numZeroes + longString.length());
for (int i = 0; i < numZeroes; i++) {
strBuffer.insert(i, '0');
}
strBuffer.append(longString);
return strBuffer.toString();
}
/**
* Encodes a positive or negative long value into a string by offsetting and
* zero-padding the number up to the specified number of digits. Use this
* encoding method if the data set includes both positive and negative
* values.
*
* @param number positive or negative long value to be encoded
* @param maxNumDigits maximum number of digits in the largest absolute
* value in the data set
* @param offsetValue offset value, has to be greater than absolute value of
* any negative number in the data set.
* @return string representation of the long
*/
public static String encodeRealNumberRange(long number, int maxNumDigits,
long offsetValue) {
long offsetNumber = number + offsetValue;
String longString = Long.toString(offsetNumber);
int numZeroes = maxNumDigits - longString.length();
StringBuffer strBuffer = new StringBuffer(numZeroes + longString.length());
for (int i = 0; i < numZeroes; i++) {
strBuffer.insert(i, '0');
}
strBuffer.append(longString);
return strBuffer.toString();
}
/**
* Encodes real float value into a string by offsetting and zero-padding
* number up to the specified number of digits. Use this encoding method if
* the data range set includes both positive and negative values.
*
* @param number float to be encoded
* @param maxDigitsLeft maximum number of digits left of the decimal point
* in the largest absolute value in the data set
* @param maxDigitsRight maximum number of digits right of the decimal point
* in the largest absolute value in the data set, i.e. precision
* @param offsetValue offset value, has to be greater than absolute value of
* any negative number in the data set.
* @return string representation of the integer
*/
public static String encodeRealNumberRange(float number, int maxDigitsLeft,
int maxDigitsRight, int offsetValue) {
int shiftMultiplier = (int) Math.pow(10, maxDigitsRight);
long shiftedNumber = Math.round((double) number * shiftMultiplier);
long shiftedOffset = offsetValue * shiftMultiplier;
long offsetNumber = shiftedNumber + shiftedOffset;
if (offsetNumber < 0)
{
throw new IllegalArgumentException("OffsetNumber[" + offsetNumber
+ "] is negative - Number[" + number + "], maxDigitsLeft[" + maxDigitsLeft
+ "], maxDigitsRight[" + maxDigitsRight + "], offsetValue[" + offsetValue + "]");
}
String longString = Long.toString(offsetNumber);
int numBeforeDecimal = longString.length();
int numZeroes = maxDigitsLeft + maxDigitsRight - numBeforeDecimal;
if (numZeroes < 0)
{
throw new IllegalArgumentException("Number[" + number
+ "] has too many digits - maxDigitsLeft[" + maxDigitsLeft
+ "], maxDigitsRight[" + maxDigitsRight + "], offsetValue[" + offsetValue + "]");
}
StringBuffer strBuffer = new StringBuffer(numZeroes + longString.length());
for (int i = 0; i < numZeroes; i++) {
strBuffer.insert(i, '0');
}
strBuffer.append(longString);
return strBuffer.toString();
}
/**
* Decodes integer value from the string representation that was created by
* using encodeRealNumberRange(..) function.
*
* @param value string representation of the integer value
* @param offsetValue offset value that was used in the original encoding
* @return original integer value
*/
public static int decodeRealNumberRangeInt(String value, int offsetValue) {
long offsetNumber = Long.parseLong(value, 10);
return (int) (offsetNumber - offsetValue);
}
/**
* Decodes a long value from the string representation that was created by
* using encodeRealNumberRange(..) function.
*
* @param value string representation of the long value
* @param offsetValue offset value that was used in the original encoding
* @return original long value
*/
public static long decodeRealNumberRangeLong(String value, long offsetValue) {
long offsetNumber = Long.parseLong(value, 10);
return offsetNumber - offsetValue;
}
/**
* Decodes float value from the string representation that was created by
* using encodeRealNumberRange(..) function.
*
* @param value string representation of the integer value
* @param maxDigitsRight maximum number of digits left of the decimal point
* in the largest absolute value in the data set (must be the
* same as the one used for encoding).
* @param offsetValue offset value that was used in the original encoding
* @return original float value
*/
public static float decodeRealNumberRangeFloat(String value,
int maxDigitsRight, int offsetValue) {
long offsetNumber = Long.parseLong(value, 10);
int shiftMultiplier = (int) Math.pow(10, maxDigitsRight);
double tempVal = offsetNumber - offsetValue * shiftMultiplier;
return (float) (tempVal / (shiftMultiplier));
}
/**
* Encodes date value into string format that can be compared
* lexicographically
*
* @param date date value to be encoded
* @return string representation of the date value
*/
public static String encodeDate(Date date) {
/* Java doesn't handle ISO8601 nicely: need to add ':' manually */
String result = DateUtils.format(DATE_FORMAT, date);
return result.substring(0, result.length() - 2) + ":"
+ result.substring(result.length() - 2);
}
/**
* Decodes date value from the string representation created using
* encodeDate(..) function.
*
* @param value string representation of the date value
* @return original date value
*/
public static Date decodeDate(String value) throws ParseException {
String javaValue = value.substring(0, value.length() - 3)
+ value.substring(value.length() - 2);
return DateUtils.parse(DATE_FORMAT, javaValue);
}
/**
* Quotes and escapes a list of values so that they can be used in a
* SimpleDB query.
*
* @param values The collection of attribute values that will be quoted,
* escaped, and included in the returned string list.
* @return A string representation of the list of specified values, with
* individual values properly quoted and escaped.
*/
public static String quoteValues(Collection<String> values) {
StringBuilder sb = new StringBuilder();
boolean first = true;
for (String s : values) {
if (!first)
sb.append(",");
first = false;
sb.append(quoteValue(s));
}
return sb.toString();
}
/**
* Quotes and escapes an attribute value by wrapping it with single quotes
* and escaping any single quotes inside the value.
*
* @param value The attribute value to quote and escape.
* @return The properly quoted and escaped attribute value, ready to be used
* in a SimpleDB select query.
*/
public static String quoteValue(String value) {
return "'" + replaceChar(value, "'", "''") + "'";
}
/**
* Quotes and escapes an attribute name or domain name by wrapping it with
* backticks and escaping any backticks inside the name.
*
* @param name The attribute name or domain name to quote and escape.
* @return The properly quoted and escaped attribute name or domain name,
* ready to be used in a SimpleDB select query.
*/
public static String quoteName(String name) {
return "`" + replaceChar(name, "`", "``") + "`";
}
protected static String replaceChar(String value, String termToFind, String replacementTerm) {
StringBuilder buffer = new StringBuilder(value);
int searchIndex = 0;
while (searchIndex < buffer.length()) {
searchIndex = buffer.indexOf(termToFind, searchIndex);
if (searchIndex == -1) {
break;
}
else {
buffer.replace(searchIndex, searchIndex + termToFind.length(), replacementTerm);
searchIndex += replacementTerm.length();
}
}
return buffer.toString();
}
}