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Common Java functionality for core functionality
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/**
*
* jerry - Common Java Functionality
* Copyright (c) 2012-2017, Sandeep Gupta
*
* http://sangupta.com/projects/jerry-core
*
* 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.sangupta.jerry.util;
import java.nio.charset.Charset;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* Utility functions around {@link String} objects.
*
* @author sangupta
*
*/
public abstract class StringUtils {
/**
* Logger instance
*/
public static final Logger LOGGER = LoggerFactory.getLogger(StringUtils.class);
/**
* UTF-8 charset object
*/
public static final Charset CHARSET_UTF8 = Charset.forName("UTF8");
/**
* Platform specific charset
*/
public static final Charset DEFAULT_CHARSET = Charset.defaultCharset();
/**
* An empty string object containing nothing.
*/
public static final String EMPTY_STRING = "";
/**
* A blank string containing one blank white-space character.
*/
public static final String BLANK_STRING = " ";
/**
* A String[] array that is empty and contains no elements
*/
public static final String[] EMPTY_STRING_LIST = new String[] { };
/**
* Defines the platform dependent line encoding
*/
public static final String SYSTEM_NEW_LINE = System.getProperty("line.separator");
/**
* Comma as a separator character
*/
public static final String COMMA_SEPARATOR_CHAR = ",";
/**
* Function to give a HEX representation of the byte array in small-case.
*
* @param bytes
* the source byte array
*
* @return the HEX coded string representing the byte array
*/
public static String asHex(byte bytes[]) {
if(bytes == null) {
return null;
}
if(bytes.length == 0) {
return StringUtils.EMPTY_STRING;
}
StringBuilder builder = new StringBuilder();
for (int i = 0; i < bytes.length; ++i) {
builder.append(Integer.toHexString((bytes[i] & 0xFF) | 0x100).substring(1, 3));
}
return builder.toString();
}
/**
* Function to return a HEX representation of the given byte in small-case.
*
* @param b
* the byte value
*
* @return the hex representation
*
*/
public static String asHex(byte b) {
return Integer.toHexString((b & 0xFF) | 0x100).substring(1, 3);
}
/**
* Return the {@link String} representation of the byte array. A
* null byte array is converted back to null, an
* empty array to an empty string or the bytes to the actual string based on
* platform encoding.
*
* @param bytes
* the byte array
*
* @return its string representation
*/
public static String asString(byte[] bytes) {
if(bytes == null) {
return null;
}
if(bytes.length == 0) {
return EMPTY_STRING;
}
return new String(bytes);
}
/**
* Return the {@link String} representation of the byte array. A
* null byte array is converted back to null, an
* empty array to an empty string or the bytes to the actual string in UTF-8
* encoding.
*
* @param bytes
* the byte array
*
* @return its string representation
*/
public static String asStringUTF8(byte[] bytes) {
if(bytes == null) {
return null;
}
if(bytes.length == 0) {
return EMPTY_STRING;
}
return new String(bytes, CHARSET_UTF8);
}
/**
* Return the actual array that this hex string represents.
*
* @param hex
* the hex string
*
* @return the actual byte array for the hex string
*/
public static byte[] fromHex(String hex) {
if(AssertUtils.isEmpty(hex)) {
return null;
}
int len = hex.length();
byte[] data = new byte[len / 2];
for (int i = 0; i < len; i += 2) {
data[i / 2] = (byte) ((Character.digit(hex.charAt(i), 16) << 4) + Character.digit(hex.charAt(i+1), 16));
}
return data;
}
/**
* Return true if the string is equal to "true" or "yes" otherwise return
* false.
*
* @param boolString
* string whose content is checked for true or false
*
* @return boolean flag indicating whether the input was true or false
*/
public static boolean getBoolean(String boolString) {
return getBoolean(boolString, false);
}
/**
* Parse the string and return the boolean value for the same. Text such as
* yes and true is treated as {@link Boolean#TRUE}
* . If the string parsing fails, the default value is returned.
*
* @param boolString
* the string to be parsed
*
* @param defaultValue
* the value to be returned, if the string does not match
*
* @return the boolean value as read by parsing the string
*/
public static boolean getBoolean(String boolString, boolean defaultValue) {
if (AssertUtils.isNotEmpty(boolString)) {
boolString = boolString.toLowerCase();
if ("yes".equals(boolString) || "true".equals(boolString) || "on".equals(boolString)) {
return true;
}
if ("no".equals(boolString) || "false".equals(boolString) || "off".equals(boolString)) {
return false;
}
}
return defaultValue;
}
public static byte getByteValue(String string, byte defaultValue) {
try {
if(AssertUtils.isNotEmpty(string)) {
return Byte.parseByte(string);
}
} catch(NumberFormatException e) {
LOGGER.debug("error getting byte from string: " + string, e);
}
return defaultValue;
}
public static char getCharValue(String string, char defaultValue) {
if(AssertUtils.isNotEmpty(string)) {
return string.charAt(0);
}
return defaultValue;
}
/**
* Parse and return the short value of the given string. If the string cannot
* be parsed, returns the default value provided
*
* @param string
* the string to be parsed
*
* @param defaultValue
* the value to be returned if parsing string fails
*
* @return the 32-bit value of the string
*/
public static short getShortValue(String string, short defaultValue) {
try {
if(AssertUtils.isNotEmpty(string)) {
return Short.parseShort(string);
}
} catch(NumberFormatException e) {
LOGGER.debug("error getting short from string: " + string, e);
}
return defaultValue;
}
/**
* Parse and return the int value of the given string. If the string cannot
* be parsed, returns the default value provided
*
* @param string
* the string to be parsed
*
* @param defaultValue
* the value to be returned if parsing string fails
*
* @return the 32-bit value of the string
*/
public static int getIntValue(String string, int defaultValue) {
try {
if(AssertUtils.isNotEmpty(string)) {
return Integer.parseInt(string);
}
} catch(NumberFormatException e) {
LOGGER.debug("error getting integer from string: " + string, e);
}
return defaultValue;
}
/**
* Parse and return the long value of the given string. If the string cannot
* be parsed, returns the default value provided
*
* @param string
* the string to be parsed
*
* @param defaultValue
* the value to be returned if parsing string fails
*
* @return the 64-bit value of the string
*/
public static long getLongValue(String string, long defaultValue) {
try {
if(AssertUtils.isNotEmpty(string)) {
return Long.parseLong(string);
}
} catch(NumberFormatException e) {
LOGGER.debug("error getting long from string: " + string, e);
}
return defaultValue;
}
/**
* Parse and return the float value of the given string. If the string cannot
* be parsed, returns the default value provided
*
* @param string
* the string to be parsed
*
* @param defaultValue
* the value to be returned if parsing string fails
*
* @return the float value of the string
*/
public static float getFloatValue(String string, float defaultValue) {
try {
if(AssertUtils.isNotEmpty(string)) {
return Float.parseFloat(string);
}
} catch(NumberFormatException e) {
LOGGER.debug("error getting long from string: " + string, e);
}
return defaultValue;
}
/**
* Parse and return the double value of the given string. If the string cannot
* be parsed, returns the default value provided
*
* @param string
* the string to be parsed
*
* @param defaultValue
* the value to be returned if parsing string fails
*
* @return the double value of the string
*/
public static double getDoubleValue(String string, double defaultValue) {
try {
if(AssertUtils.isNotEmpty(string)) {
return Double.parseDouble(string);
}
} catch(NumberFormatException e) {
LOGGER.debug("error getting long from string: " + string, e);
}
return defaultValue;
}
/**
* Generate a given appender delimited string of all items in the list. If
* the list has no elements, an empty string is returned back.
*
* @param list
* the list containing objects to be joined
*
* @param appender
* the appender to be used
*
* @param
* the type of instances contained in the collection
*
* @return the string representation of list using appender as the delimiter
*/
public static String listToString(List list, String appender) {
if(AssertUtils.isEmpty(list)) {
return EMPTY_STRING;
}
final boolean hasAppender = AssertUtils.isNotEmpty(appender);
StringBuilder builder = new StringBuilder();
for(int index = 0; index < list.size(); index++) {
if(hasAppender && index > 0) {
builder.append(appender);
}
builder.append(list.get(index));
}
return builder.toString();
}
/**
* Check if a value is contained in the list.
*
* @param list
* the list of values
*
* @param value
* the value that needs to be checked for presence in list
*
* @return true if the value exists in list, false
* otherwise.
*
*/
public static boolean contains(String[] list, String value) {
if(list == null) {
return false;
}
if(list.length == 0) {
return false;
}
for(String item : list) {
if(item.equals(value)) {
return true;
}
}
return false;
}
/**
* Return a subset of string from the location where the given 'from' word
* exists.
*
* @param string
* the string from which substring needs to be extracted
*
* @param from
* the string to be looked
*
* @param searchIndex
* the index from which the string needs to be searched
*
* @return the substring after the word is found inside the main string
*/
public static String substringAfter(String string, String from, int searchIndex) {
if(AssertUtils.isEmpty(string)) {
return EMPTY_STRING;
}
if(AssertUtils.isEmpty(from)) {
return string;
}
int index = string.indexOf(from, searchIndex);
if(index == -1) {
return EMPTY_STRING;
}
return string.substring(index + from.length());
}
/**
* Find the substring between the given prefix and suffix.
*
* @param string
* the string which needs to be sub-string'ed
*
* @param prefix
* the string before
*
* @param suffix
* the string after
*
* @return the sub-string between the prefix and suffix
*
*/
public static String substringBetween(String string, String prefix, String suffix) {
return StringUtils.substringBetween(string, prefix, suffix, 0);
}
/**
* Find the substring between the given prefix and suffix.
*
* @param string
* the string which needs to be sub-string'ed
*
* @param prefix
* the string before
*
* @param suffix
* the string after
*
* @param startSearch
* the index to start searching the prefix from
*
* @return the sub-string between the prefix and suffix
*
*/
public static String substringBetween(String string, String prefix, String suffix, int startSearch) {
if(AssertUtils.isEmpty(string)) {
return EMPTY_STRING;
}
int begin = 0, end = string.length();
if(AssertUtils.isNotBlank(prefix)) {
begin = string.indexOf(prefix, startSearch);
if(begin != -1) {
begin += prefix.length();
} else {
begin = 0;
}
}
if(AssertUtils.isNotEmpty(suffix)) {
end = string.indexOf(suffix, begin);
if(end == -1) {
end = string.length();
}
}
return string.substring(begin, end);
}
/**
* Find the last index of searchString inside string, where searchString
* occurs before the suffix in the string.
*
* @param string
* the string in which the search will be performed
*
* @param searchString
* the string that needs to be searched
*
* @param suffix
* the string that decides the end location of the search
*
* @return the index of searchString inside string, terminated at point
* where suffix occurs
*
*/
public static int lastIndexBefore(String string, String searchString, String suffix) {
if(AssertUtils.isEmpty(string)) {
return -1;
}
if(AssertUtils.isEmpty(searchString)) {
return -1;
}
int index = string.indexOf(suffix);
if(index != -1) {
string = string.substring(0, index);
}
return string.lastIndexOf(searchString);
}
public static int lastIndexBefore(String string, String searchString, int maxSuffix) {
if(AssertUtils.isEmpty(string)) {
return -1;
}
if(AssertUtils.isEmpty(searchString)) {
return -1;
}
if(maxSuffix == -1) {
return string.lastIndexOf(searchString);
}
maxSuffix = maxSuffix - searchString.length() + 1;
int start = -2;
int index = -1;
do {
index = string.indexOf(searchString, start + 1);
if(index == -1) {
break;
}
if(index >= maxSuffix) {
index = start;
break;
}
start = index;
} while(true);
if(start < 0) {
return -1;
}
return start;
}
/**
* Find the nth index of a string-part inside another string.
*
* @param string
* the string in which the search will be performed
*
* @param searchString
* the string that needs to be searched
*
* @param n
* the occurrence number that we are looking for
*
* @return the index of nth occurrence of searchString inside string
*/
public static int nthIndexOf(String string, String searchString, int n) {
if(n <= 0) {
throw new IllegalArgumentException("n cannot be less than, or equal to zero");
}
if(n == 1) {
return string.indexOf(searchString);
}
int count = 0;
int index = -1;
do {
index = string.indexOf(searchString, index + 1);
if(index == -1) {
return -1;
}
count++;
if(count == n) {
return index;
}
} while(true);
}
/**
* Check if the given string starts with the given prefix, ignoring case.
*
* @param text
* the string to search in
*
* @param prefix
* the prefix to search for
*
* @return true if the string starts with prefix,
* false otherwise
*/
public static boolean startsWithIgnoreCase(String text, String prefix) {
if(AssertUtils.isEmpty(text)) {
return false;
}
if(AssertUtils.isEmpty(prefix)) {
return false;
}
if(text == prefix) {
return true; // same string
}
if(prefix.length() > text.length()) {
return false;
}
if(text.substring(0, prefix.length()).equalsIgnoreCase(prefix)) {
return true;
}
return false;
}
/**
* Check if the given string ends with the given suffix, ignoring case.
*
* @param text
* the string to search in
*
* @param suffix
* the suffix to search for
*
* @return true if the string ends with suffix,
* false otherwise
*/
public static boolean endsWithIgnoreCase(String text, String suffix) {
if(AssertUtils.isEmpty(text)) {
return false;
}
if(AssertUtils.isEmpty(suffix)) {
return false;
}
if(text == suffix) {
return true; // same string
}
int start = text.length() - suffix.length();
if(start < 0) {
return false;
}
if(text.substring(start).equalsIgnoreCase(suffix)) {
return true;
}
return false;
}
/**
* Merge the items into a single string separated by the given delimiter
*
* @param items
* Items to be merged into a string
*
* @param delimiter
* the character delimiter to be used
*
* @return the merged string
*/
public static String merge(String[] items, char delimiter) {
if(AssertUtils.isEmpty(items)) {
return StringUtils.EMPTY_STRING;
}
StringBuilder builder = new StringBuilder(1024);
for(int index = 0; index < items.length; index++) {
if(index > 0) {
builder.append(delimiter);
}
builder.append(items[index]);
}
return builder.toString();
}
/**
* Merge the items into a single string separated by the given delimiter
*
* @param items
* Items to be merged into a string
*
* @param delimiter
* the string delimiter to be used
*
* @return the merged string
*/
public static String merge(String[] items, String delimiter) {
if(AssertUtils.isEmpty(items)) {
return StringUtils.EMPTY_STRING;
}
boolean addDelimiter = AssertUtils.isNotEmpty(delimiter);
StringBuilder builder = new StringBuilder(1024);
for(int index = 0; index < items.length; index++) {
if(addDelimiter) {
if(index > 0) {
builder.append(delimiter);
}
}
builder.append(items[index]);
}
return builder.toString();
}
/**
* Return a string containing the same character the given number of times.
*
* @param ch
* the character to repeat
*
* @param times
* the number of times to use
*
* @return the {@link String} instance thus created
*
* @throws IllegalArgumentException
* if the number of times to repeat is less than or equal to
* ZERO
*/
public static String repeat(char ch, int times) {
if(times <= 0) {
throw new IllegalArgumentException("Length cannot be less than or equal to zero");
}
if(times == 1) {
return String.valueOf(ch);
}
char[] array = new char[times];
Arrays.fill(array, ch);
return new String(array);
}
/**
* Convert the property name to JSON valid property name. Convert all
* illegal characters to underscore.
*
* @param name
* the property name to convert
*
* @return the converted property name
*/
public static String convertToJsonPropertyName(String name) {
char[] chars = name.toCharArray();
for(int index = 0; index < chars.length; index++) {
char c = chars[index];
if(!(('a' <= c && c <= 'z') || ('A' <= c && c <= 'Z') || ('0' <= c && c <= '9') || (c == '_') || (c == '-'))) {
chars[index] = '_';
}
}
return new String(chars);
}
/**
* Convert the property name to XML valid property name. Convert all illegal
* characters to hyphen.
*
* @param name
* the property name to convert
*
* @return the converted property name
*/
public static String convertToXmlPropertyName(String name) {
char[] chars = name.toCharArray();
for(int index = 0; index < chars.length; index++) {
char c = chars[index];
if(!(('a' <= c && c <= 'z') || ('A' <= c && c <= 'Z') || ('0' <= c && c <= '9') || (c == '_') || (c == '-'))) {
chars[index] = '-';
}
}
return new String(chars);
}
/**
* Returns a {@link String} filled with random characters of given length.
*
* @param length
* the number of characters to create. If value is less than or equal
* to zero, an {@link IllegalArgumentException} is thrown
*
* @return the randomly generated string
*
* @throws IllegalArgumentException
* if length is less than or equal to zero
*/
public static String getRandomString(int length) {
if(length <= 0) {
throw new IllegalArgumentException("Length cannot be less than or equal to zero");
}
byte[] bytes = ByteArrayUtils.getRandomBytes(length);
return new String(bytes);
}
/**
* Stringify the array by joining elements taking comma as a separator.
*
* @param array
* the array to be stringified
*
* @return the {@link String} representation or null
*/
public static String stringifyArray(Object[] array) {
if(AssertUtils.isEmpty(array)) {
return null;
}
// compute space requirement
int size = 0;
if(array instanceof String[]) {
String[] strArray = (String[]) array;
for(String str : strArray) {
if(str != null) {
size += str.length();
}
}
// add additional space for separators
size = size + (2 * array.length);
}
final StringBuilder builder;
if(size > 0) {
builder = new StringBuilder(size);
} else {
builder = new StringBuilder();
}
boolean first = true;
for(int index = 0; index < array.length; index++) {
Object object = array[index];
if(!first) {
builder.append(COMMA_SEPARATOR_CHAR);
}
if(object == null) {
continue;
}
builder.append(object.toString());
first = false;
}
return builder.toString();
}
/**
* Stringify an integer-array.
*
* @param array
* the int[] array to be stringified
*
* @return the {@link String} representation or null
*/
public static String stringifyArray(int[] array) {
if(AssertUtils.isEmpty(array)) {
return null;
}
StringBuilder builder = new StringBuilder(11 * array.length);
boolean first = true;
for(int integer : array) {
if(!first) {
builder.append(COMMA_SEPARATOR_CHAR);
}
builder.append(String.valueOf(integer));
// set first to false
first = false;
}
return builder.toString();
}
/**
* Stringify a short-array.
*
* @param array
* the short[] array to be stringified
*
* @return the {@link String} representation or null
*/
public static String stringifyArray(short[] array) {
if(AssertUtils.isEmpty(array)) {
return null;
}
StringBuilder builder = new StringBuilder(7 * array.length);
boolean first = true;
for(short value : array) {
if(!first) {
builder.append(COMMA_SEPARATOR_CHAR);
}
builder.append(String.valueOf(value));
// set first to false
first = false;
}
return builder.toString();
}
/**
* Stringify a long-array.
*
* @param array
* the long[] array to be stringified
*
* @return the {@link String} representation or null
*/
public static String stringifyArray(long[] array) {
if(AssertUtils.isEmpty(array)) {
return null;
}
StringBuilder builder = new StringBuilder(15 * array.length);
boolean first = true;
for(long value : array) {
if(!first) {
builder.append(COMMA_SEPARATOR_CHAR);
}
builder.append(String.valueOf(value));
// set first to false
first = false;
}
return builder.toString();
}
/**
* Stringify a char-array.
*
* @param array
* the char[] array to be stringified
*
* @return the {@link String} representation or null
*/
public static String stringifyArray(char[] array) {
if(AssertUtils.isEmpty(array)) {
return null;
}
StringBuilder builder = new StringBuilder(2 * array.length);
boolean first = true;
for(char value : array) {
if(!first) {
builder.append(COMMA_SEPARATOR_CHAR);
}
builder.append(String.valueOf(value));
// set first to false
first = false;
}
return builder.toString();
}
/**
* Stringify a float-array.
*
* @param array
* the float[] array to be stringified
*
* @return the {@link String} representation or null
*/
public static String stringifyArray(float[] array) {
if(AssertUtils.isEmpty(array)) {
return null;
}
StringBuilder builder = new StringBuilder(15 * array.length);
boolean first = true;
for(float value : array) {
if(!first) {
builder.append(COMMA_SEPARATOR_CHAR);
}
builder.append(String.valueOf(value));
// set first to false
first = false;
}
return builder.toString();
}
/**
* Stringify a double-array.
*
* @param array
* the double[] array to be stringified
*
* @return the {@link String} representation or null
*/
public static String stringifyArray(double[] array) {
if(AssertUtils.isEmpty(array)) {
return null;
}
StringBuilder builder = new StringBuilder(15 * array.length);
boolean first = true;
for(double value : array) {
if(!first) {
builder.append(COMMA_SEPARATOR_CHAR);
}
builder.append(String.valueOf(value));
// set first to false
first = false;
}
return builder.toString();
}
/**
* Stringify a byte-array.
*
* @param array
* the byte[] array to be stringified
*
* @return the {@link String} representation or null
*/
public static String stringifyArray(byte[] array) {
if(AssertUtils.isEmpty(array)) {
return null;
}
StringBuilder builder = new StringBuilder(5 * array.length);
boolean first = true;
for(byte value : array) {
if(!first) {
builder.append(COMMA_SEPARATOR_CHAR);
}
builder.append(String.valueOf(value));
// set first to false
first = false;
}
return builder.toString();
}
/**
* Stringify a boolean-array.
*
* @param array
* the boolean[] array to be stringified
*
* @return the {@link String} representation or null
*/
public static String stringifyArray(boolean[] array) {
if(AssertUtils.isEmpty(array)) {
return null;
}
StringBuilder builder = new StringBuilder(5 * array.length);
boolean first = true;
for(boolean value : array) {
if(!first) {
builder.append(COMMA_SEPARATOR_CHAR);
}
builder.append(String.valueOf(value));
// set first to false
first = false;
}
return builder.toString();
}
/**
* Construct back a byte-array from its stringified representation.
*
* @param value
* the {@link String} representation
*
* @return the byte[] thus constructed, or null
*
* @throws NumberFormatException
* if any of the value cannot be parsed
*/
public static byte[] deStringifyByteArray(String value) {
if(AssertUtils.isEmpty(value)) {
return null;
}
String[] tokens = value.split(COMMA_SEPARATOR_CHAR);
byte[] array = new byte[tokens.length];
for(int index = 0; index < tokens.length; index++) {
array[index] = Byte.parseByte(tokens[index]);
}
return array;
}
/**
* Construct back a char-array from its stringified representation.
*
* @param value
* the {@link String} representation
*
* @return the char[] thus constructed, or null
*
* @throws NumberFormatException
* if any of the value cannot be parsed
*/
public static char[] deStringifyCharArray(String value) {
if(AssertUtils.isEmpty(value)) {
return null;
}
String[] tokens = value.split(COMMA_SEPARATOR_CHAR);
char[] array = new char[tokens.length];
for(int index = 0; index < tokens.length; index++) {
array[index] = tokens[index].charAt(0);
}
return array;
}
/**
* Construct back a short-array from its stringified representation.
*
* @param value
* the {@link String} representation
*
* @return the short[] thus constructed, or null
*
* @throws NumberFormatException
* if any of the value cannot be parsed
*/
public static short[] deStringifyShortArray(String value) {
if(AssertUtils.isEmpty(value)) {
return null;
}
String[] tokens = value.split(COMMA_SEPARATOR_CHAR);
short[] array = new short[tokens.length];
for(int index = 0; index < tokens.length; index++) {
array[index] = Short.valueOf(tokens[index]);
}
return array;
}
/**
* Construct back a boolean-array from its stringified representation.
*
* @param value
* the {@link String} representation
*
* @return the boolean[] thus constructed, or null
*
* @throws NumberFormatException
* if any of the value cannot be parsed
*/
public static boolean[] deStringifyBooleanArray(String value) {
if(AssertUtils.isEmpty(value)) {
return null;
}
String[] tokens = value.split(COMMA_SEPARATOR_CHAR);
boolean[] array = new boolean[tokens.length];
for(int index = 0; index < tokens.length; index++) {
array[index] = getBoolean(tokens[index]);
}
return array;
}
/**
* Construct back a int-array from its stringified representation.
*
* @param value
* the {@link String} representation
*
* @return the int[] thus constructed, or null
*
* @throws NumberFormatException
* if any of the value cannot be parsed
*/
public static int[] deStringifyIntArray(String value) {
if(AssertUtils.isEmpty(value)) {
return null;
}
String[] tokens = value.split(COMMA_SEPARATOR_CHAR);
int[] array = new int[tokens.length];
for(int index = 0; index < tokens.length; index++) {
array[index] = Integer.parseInt(tokens[index]);
}
return array;
}
/**
* Construct back a long-array from its stringified representation.
*
* @param value
* the {@link String} representation
*
* @return the long[] thus constructed, or null
*
* @throws NumberFormatException
* if any of the value cannot be parsed
*/
public static long[] deStringifyLongArray(String value) {
if(AssertUtils.isEmpty(value)) {
return null;
}
String[] tokens = value.split(COMMA_SEPARATOR_CHAR);
long[] array = new long[tokens.length];
for(int index = 0; index < tokens.length; index++) {
array[index] = Long.valueOf(tokens[index]);
}
return array;
}
/**
* Construct back a float-array from its stringified representation.
*
* @param value
* the {@link String} representation
*
* @return the float[] thus constructed, or null
*
* @throws NumberFormatException
* if any of the value cannot be parsed
*/
public static float[] deStringifyFloatArray(String value) {
if(AssertUtils.isEmpty(value)) {
return null;
}
String[] tokens = value.split(COMMA_SEPARATOR_CHAR);
float[] array = new float[tokens.length];
for(int index = 0; index < tokens.length; index++) {
array[index] = Float.valueOf(tokens[index]);
}
return array;
}
/**
* Construct back a double-array from its stringified representation.
*
* @param value
* the {@link String} representation
*
* @return the double[] thus constructed, or null
*
* @throws NumberFormatException
* if any of the value cannot be parsed
*/
public static double[] deStringifyDoubleArray(String value) {
if(AssertUtils.isEmpty(value)) {
return null;
}
String[] tokens = value.split(COMMA_SEPARATOR_CHAR);
double[] array = new double[tokens.length];
for(int index = 0; index < tokens.length; index++) {
array[index] = Double.valueOf(tokens[index]);
}
return array;
}
public static boolean wildcardMatch(String string, String pattern) {
int i = 0;
int j = 0;
int starIndex = -1;
int iIndex = -1;
while (i < string.length()) {
if (j < pattern.length() && (pattern.charAt(j) == '?' || pattern.charAt(j) == string.charAt(i))) {
++i;
++j;
} else if (j < pattern.length() && pattern.charAt(j) == '*') {
starIndex = j;
iIndex = i;
j++;
} else if (starIndex != -1) {
j = starIndex + 1;
i = iIndex+1;
iIndex++;
} else {
return false;
}
}
while (j < pattern.length() && pattern.charAt(j) == '*') {
++j;
}
return j == pattern.length();
}
/**
* Count the occurrences of the given character in the given string.
*
* @param string
* the string to look in for
*
* @param chr
* the character being looked
*
* @return the number of occurrences
*/
public static int count(String string, char chr) {
if(AssertUtils.isEmpty(string)) {
return 0;
}
int count = 0;
char[] array = string.toCharArray();
for(char c : array) {
if(c == chr) {
count++;
}
}
return count;
}
/**
* Remove all occurrences of a {@link String} from another {@link String}
*
* @param str
* the {@link String} to remove portions from
*
* @param toRemove
* the {@link String} to be removed
*
* @return the final constructued {@link String}
*/
public static String removeAll(String str, String toRemove) {
if(AssertUtils.isEmpty(str)) {
return str;
}
if(AssertUtils.isEmpty(toRemove)) {
return str;
}
char[] array = str.toCharArray();
StringBuilder builder = new StringBuilder(array.length);
for(char c : array) {
if(toRemove.contains(String.valueOf(c))) {
continue;
}
builder.append(c);
}
return builder.toString();
}
/**
* Remove white-spaces from the start of the given string. If given string
* is null, an empty {@link String} is returned.
*
* @param str
* the string to be cleaned up
*
* @return the cleaned {@link String}
*/
public static String ltrim(String str) {
if(AssertUtils.isEmpty(str)) {
return "";
}
int i = 0;
while (i < str.length() && Character.isWhitespace(str.charAt(i))) {
i++;
}
return str.substring(i);
}
/**
* Remove white-spaces from the end of the given string. If given string is
* null, an empty {@link String} is returned.
*
* @param str
* the string to be cleaned up
*
* @return the cleaned {@link String}
*/
public static String rtrim(String str) {
if(AssertUtils.isEmpty(str)) {
return "";
}
int i = str.length() - 1;
while (i >= 0 && Character.isWhitespace(str.charAt(i))) {
i--;
}
return str.substring(0,i+1);
}
public static String[] split(final String str, final String separatorChars) {
return splitWorker(str, separatorChars, -1, false);
}
private static String[] splitWorker(final String str, final String separatorChars, final int max, final boolean preserveAllTokens) {
// Performance tuned for 2.0 (JDK1.4)
// Direct code is quicker than StringTokenizer.
// Also, StringTokenizer uses isSpace() not isWhitespace()
if (str == null) {
return null;
}
final int len = str.length();
if (len == 0) {
return StringUtils.EMPTY_STRING_LIST;
}
final List list = new ArrayList<>();
int sizePlus1 = 1;
int i = 0, start = 0;
boolean match = false;
boolean lastMatch = false;
if (separatorChars == null) {
// Null separator means use whitespace
while (i < len) {
if (Character.isWhitespace(str.charAt(i))) {
if (match || preserveAllTokens) {
lastMatch = true;
if (sizePlus1++ == max) {
i = len;
lastMatch = false;
}
list.add(str.substring(start, i));
match = false;
}
start = ++i;
continue;
}
lastMatch = false;
match = true;
i++;
}
} else if (separatorChars.length() == 1) {
// Optimise 1 character case
final char sep = separatorChars.charAt(0);
while (i < len) {
if (str.charAt(i) == sep) {
if (match || preserveAllTokens) {
lastMatch = true;
if (sizePlus1++ == max) {
i = len;
lastMatch = false;
}
list.add(str.substring(start, i));
match = false;
}
start = ++i;
continue;
}
lastMatch = false;
match = true;
i++;
}
} else {
// standard case
while (i < len) {
if (separatorChars.indexOf(str.charAt(i)) >= 0) {
if (match || preserveAllTokens) {
lastMatch = true;
if (sizePlus1++ == max) {
i = len;
lastMatch = false;
}
list.add(str.substring(start, i));
match = false;
}
start = ++i;
continue;
}
lastMatch = false;
match = true;
i++;
}
}
if (match || preserveAllTokens && lastMatch) {
list.add(str.substring(start, i));
}
return list.toArray(new String[list.size()]);
}
}
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