org.datavec.api.util.StringUtils Maven / Gradle / Ivy
/*-
* * Copyright 2016 Skymind, 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 org.datavec.api.util;
import java.io.PrintWriter;
import java.io.StringWriter;
import java.net.InetAddress;
import java.net.URI;
import java.net.URISyntaxException;
import java.net.UnknownHostException;
import java.text.DateFormat;
import java.text.DecimalFormat;
import java.text.NumberFormat;
import java.util.*;
/**
* General string utils
*/
public class StringUtils {
private static final DecimalFormat decimalFormat;
static {
NumberFormat numberFormat = NumberFormat.getNumberInstance(Locale.ENGLISH);
decimalFormat = (DecimalFormat) numberFormat;
decimalFormat.applyPattern("#.##");
}
/**
* Make a string representation of the exception.
* @param e The exception to stringify
* @return A string with exception name and call stack.
*/
public static String stringifyException(Throwable e) {
StringWriter stm = new StringWriter();
PrintWriter wrt = new PrintWriter(stm);
e.printStackTrace(wrt);
wrt.close();
return stm.toString();
}
/**
* Given a full hostname, return the word upto the first dot.
* @param fullHostname the full hostname
* @return the hostname to the first dot
*/
public static String simpleHostname(String fullHostname) {
int offset = fullHostname.indexOf('.');
if (offset != -1) {
return fullHostname.substring(0, offset);
}
return fullHostname;
}
private static DecimalFormat oneDecimal = new DecimalFormat("0.0");
/**
* Given an integer, return a string that is in an approximate, but human
* readable format.
* It uses the bases 'k', 'm', and 'g' for 1024, 1024**2, and 1024**3.
* @param number the number to format
* @return a human readable form of the integer
*/
public static String humanReadableInt(long number) {
long absNumber = Math.abs(number);
double result = number;
String suffix = "";
if (absNumber < 1024) {
// do nothing
} else if (absNumber < 1024 * 1024) {
result = number / 1024.0;
suffix = "k";
} else if (absNumber < 1024 * 1024 * 1024) {
result = number / (1024.0 * 1024);
suffix = "m";
} else {
result = number / (1024.0 * 1024 * 1024);
suffix = "g";
}
return oneDecimal.format(result) + suffix;
}
/**
* Format a percentage for presentation to the user.
* @param done the percentage to format (0.0 to 1.0)
* @param digits the number of digits past the decimal point
* @return a string representation of the percentage
*/
public static String formatPercent(double done, int digits) {
DecimalFormat percentFormat = new DecimalFormat("0.00%");
double scale = Math.pow(10.0, digits + 2);
double rounded = Math.floor(done * scale);
percentFormat.setDecimalSeparatorAlwaysShown(false);
percentFormat.setMinimumFractionDigits(digits);
percentFormat.setMaximumFractionDigits(digits);
return percentFormat.format(rounded / scale);
}
/**
* Given an array of strings, return a comma-separated list of its elements.
* @param strs Array of strings
* @return Empty string if strs.length is 0, comma separated list of strings
* otherwise
*/
public static String arrayToString(String[] strs) {
if (strs.length == 0) {
return "";
}
StringBuilder sbuf = new StringBuilder();
sbuf.append(strs[0]);
for (int idx = 1; idx < strs.length; idx++) {
sbuf.append(",");
sbuf.append(strs[idx]);
}
return sbuf.toString();
}
/**
* Given an array of bytes it will convert the bytes to a hex string
* representation of the bytes
* @param bytes
* @param start start index, inclusively
* @param end end index, exclusively
* @return hex string representation of the byte array
*/
public static String byteToHexString(byte[] bytes, int start, int end) {
if (bytes == null) {
throw new IllegalArgumentException("bytes == null");
}
StringBuilder s = new StringBuilder();
for (int i = start; i < end; i++) {
s.append(String.format("%02x", bytes[i]));
}
return s.toString();
}
/** Same as byteToHexString(bytes, 0, bytes.length). */
public static String byteToHexString(byte bytes[]) {
return byteToHexString(bytes, 0, bytes.length);
}
/**
* Given a hexstring this will return the byte array corresponding to the
* string
* @param hex the hex String array
* @return a byte array that is a hex string representation of the given
* string. The size of the byte array is therefore hex.length/2
*/
public static byte[] hexStringToByte(String hex) {
byte[] bts = new byte[hex.length() / 2];
for (int i = 0; i < bts.length; i++) {
bts[i] = (byte) Integer.parseInt(hex.substring(2 * i, 2 * i + 2), 16);
}
return bts;
}
/**
*
* @param uris
*/
public static String uriToString(URI[] uris) {
if (uris == null) {
return null;
}
StringBuilder ret = new StringBuilder(uris[0].toString());
for (int i = 1; i < uris.length; i++) {
ret.append(",");
ret.append(uris[i].toString());
}
return ret.toString();
}
/**
*
* @param str
*/
public static URI[] stringToURI(String[] str) {
if (str == null)
return null;
URI[] uris = new URI[str.length];
for (int i = 0; i < str.length; i++) {
try {
uris[i] = new URI(str[i]);
} catch (URISyntaxException ur) {
System.out.println("Exception in specified URI's " + StringUtils.stringifyException(ur));
//making sure its assigned to null in case of an error
uris[i] = null;
}
}
return uris;
}
/**
*
* Given a finish and start time in long milliseconds, returns a
* String in the format Xhrs, Ymins, Z sec, for the time difference between two times.
* If finish time comes before start time then negative valeus of X, Y and Z wil return.
*
* @param finishTime finish time
* @param startTime start time
*/
public static String formatTimeDiff(long finishTime, long startTime) {
long timeDiff = finishTime - startTime;
return formatTime(timeDiff);
}
/**
*
* Given the time in long milliseconds, returns a
* String in the format Xhrs, Ymins, Z sec.
*
* @param timeDiff The time difference to format
*/
public static String formatTime(long timeDiff) {
StringBuilder buf = new StringBuilder();
long hours = timeDiff / (60 * 60 * 1000);
long rem = (timeDiff % (60 * 60 * 1000));
long minutes = rem / (60 * 1000);
rem = rem % (60 * 1000);
long seconds = rem / 1000;
if (hours != 0) {
buf.append(hours);
buf.append("hrs, ");
}
if (minutes != 0) {
buf.append(minutes);
buf.append("mins, ");
}
// return "0sec if no difference
buf.append(seconds);
buf.append("sec");
return buf.toString();
}
/**
* Formats time in ms and appends difference (finishTime - startTime)
* as returned by formatTimeDiff().
* If finish time is 0, empty string is returned, if start time is 0
* then difference is not appended to return value.
* @param dateFormat date format to use
* @param finishTime fnish time
* @param startTime start time
* @return formatted value.
*/
public static String getFormattedTimeWithDiff(DateFormat dateFormat, long finishTime, long startTime) {
StringBuilder buf = new StringBuilder();
if (0 != finishTime) {
buf.append(dateFormat.format(new Date(finishTime)));
if (0 != startTime) {
buf.append(" (" + formatTimeDiff(finishTime, startTime) + ")");
}
}
return buf.toString();
}
/**
* Returns an arraylist of strings.
* @param str the comma seperated string values
* @return the arraylist of the comma seperated string values
*/
public static String[] getStrings(String str) {
Collection values = getStringCollection(str);
if (values.size() == 0) {
return null;
}
return values.toArray(new String[values.size()]);
}
/**
* Returns a collection of strings.
* @param str comma seperated string values
* @return an ArrayList of string values
*/
public static Collection getStringCollection(String str) {
List values = new ArrayList<>();
if (str == null)
return values;
StringTokenizer tokenizer = new StringTokenizer(str, ",");
values = new ArrayList<>();
while (tokenizer.hasMoreTokens()) {
values.add(tokenizer.nextToken());
}
return values;
}
/**
* Splits a comma separated value String, trimming leading and trailing whitespace on each value.
* @param str a comma separated with values
* @return a Collection of String values
*/
public static Collection getTrimmedStringCollection(String str) {
return Arrays.asList(getTrimmedStrings(str));
}
/**
* Splits a comma separated value String, trimming leading and trailing whitespace on each value.
* @param str a comma separated with values
* @return an array of String values
*/
public static String[] getTrimmedStrings(String str) {
if (null == str || "".equals(str.trim())) {
return emptyStringArray;
}
return str.trim().split("\\s*,\\s*");
}
final public static String[] emptyStringArray = {};
final public static char COMMA = ',';
final public static char ESCAPE_CHAR = '\\';
/**
* Split a string using the default separator
* @param str a string that may have escaped separator
* @return an array of strings
*/
public static String[] split(String str) {
return split(str, ESCAPE_CHAR, COMMA);
}
/**
* Split a string using the given separator
* @param str a string that may have escaped separator
* @param escapeChar a char that be used to escape the separator
* @param separator a separator char
* @return an array of strings
*/
public static String[] split(String str, char escapeChar, char separator) {
if (str == null) {
return null;
}
List strList = new ArrayList<>();
StringBuilder split = new StringBuilder();
int index = 0;
while ((index = findNext(str, separator, escapeChar, index, split)) >= 0) {
++index; // move over the separator for next search
strList.add(split.toString());
split.setLength(0); // reset the buffer
}
strList.add(split.toString());
// remove trailing empty split(s)
int last = strList.size(); // last split
while (--last >= 0 && "".equals(strList.get(last))) {
strList.remove(last);
}
return strList.toArray(new String[strList.size()]);
}
/**
* Finds the first occurrence of the separator character ignoring the escaped
* separators starting from the index. Note the substring between the index
* and the position of the separator is passed.
* @param str the source string
* @param separator the character to find
* @param escapeChar character used to escape
* @param start from where to search
* @param split used to pass back the extracted string
*/
public static int findNext(String str, char separator, char escapeChar, int start, StringBuilder split) {
int numPreEscapes = 0;
for (int i = start; i < str.length(); i++) {
char curChar = str.charAt(i);
if (numPreEscapes == 0 && curChar == separator) { // separator
return i;
} else {
split.append(curChar);
numPreEscapes = (curChar == escapeChar) ? (++numPreEscapes) % 2 : 0;
}
}
return -1;
}
/**
* Escape commas in the string using the default escape char
* @param str a string
* @return an escaped string
*/
public static String escapeString(String str) {
return escapeString(str, ESCAPE_CHAR, COMMA);
}
/**
* Escape charToEscape in the string
* with the escape char escapeChar
*
* @param str string
* @param escapeChar escape char
* @param charToEscape the char to be escaped
* @return an escaped string
*/
public static String escapeString(String str, char escapeChar, char charToEscape) {
return escapeString(str, escapeChar, new char[] {charToEscape});
}
// check if the character array has the character
private static boolean hasChar(char[] chars, char character) {
for (char target : chars) {
if (character == target) {
return true;
}
}
return false;
}
/**
* @param charsToEscape array of characters to be escaped
*/
public static String escapeString(String str, char escapeChar, char[] charsToEscape) {
if (str == null) {
return null;
}
StringBuilder result = new StringBuilder();
for (int i = 0; i < str.length(); i++) {
char curChar = str.charAt(i);
if (curChar == escapeChar || hasChar(charsToEscape, curChar)) {
// special char
result.append(escapeChar);
}
result.append(curChar);
}
return result.toString();
}
/**
* Unescape commas in the string using the default escape char
* @param str a string
* @return an unescaped string
*/
public static String unEscapeString(String str) {
return unEscapeString(str, ESCAPE_CHAR, COMMA);
}
/**
* Unescape charToEscape in the string
* with the escape char escapeChar
*
* @param str string
* @param escapeChar escape char
* @param charToEscape the escaped char
* @return an unescaped string
*/
public static String unEscapeString(String str, char escapeChar, char charToEscape) {
return unEscapeString(str, escapeChar, new char[] {charToEscape});
}
/**
* @param charsToEscape array of characters to unescape
*/
public static String unEscapeString(String str, char escapeChar, char[] charsToEscape) {
if (str == null) {
return null;
}
StringBuilder result = new StringBuilder(str.length());
boolean hasPreEscape = false;
for (int i = 0; i < str.length(); i++) {
char curChar = str.charAt(i);
if (hasPreEscape) {
if (curChar != escapeChar && !hasChar(charsToEscape, curChar)) {
// no special char
throw new IllegalArgumentException(
"Illegal escaped string " + str + " unescaped " + escapeChar + " at " + (i - 1));
}
// otherwise discard the escape char
result.append(curChar);
hasPreEscape = false;
} else {
if (hasChar(charsToEscape, curChar)) {
throw new IllegalArgumentException(
"Illegal escaped string " + str + " unescaped " + curChar + " at " + i);
} else if (curChar == escapeChar) {
hasPreEscape = true;
} else {
result.append(curChar);
}
}
}
if (hasPreEscape) {
throw new IllegalArgumentException(
"Illegal escaped string " + str + ", not expecting " + escapeChar + " in the end.");
}
return result.toString();
}
/**
* Return hostname without throwing exception.
* @return hostname
*/
public static String getHostname() {
try {
return "" + InetAddress.getLocalHost();
} catch (UnknownHostException uhe) {
return "" + uhe;
}
}
/**
* Return a message for logging.
* @param prefix prefix keyword for the message
* @param msg content of the message
* @return a message for logging
*/
private static String toStartupShutdownString(String prefix, String[] msg) {
StringBuilder b = new StringBuilder(prefix);
b.append("\n/************************************************************");
for (String s : msg)
b.append("\n" + prefix + s);
b.append("\n************************************************************/");
return b.toString();
}
/**
* The traditional binary prefixes, kilo, mega, ..., exa,
* which can be represented by a 64-bit integer.
* TraditionalBinaryPrefix symbol are case insensitive.
*/
public static enum TraditionalBinaryPrefix {
KILO(1024), MEGA(KILO.value << 10), GIGA(MEGA.value << 10), TERA(GIGA.value << 10), PETA(TERA.value << 10), EXA(
PETA.value << 10);
public final long value;
public final char symbol;
TraditionalBinaryPrefix(long value) {
this.value = value;
this.symbol = toString().charAt(0);
}
/**
* @return The TraditionalBinaryPrefix object corresponding to the symbol.
*/
public static TraditionalBinaryPrefix valueOf(char symbol) {
symbol = Character.toUpperCase(symbol);
for (TraditionalBinaryPrefix prefix : TraditionalBinaryPrefix.values()) {
if (symbol == prefix.symbol) {
return prefix;
}
}
throw new IllegalArgumentException("Unknown symbol '" + symbol + "'");
}
/**
* Convert a string to long.
* The input string is first be trimmed
* and then it is parsed with traditional binary prefix.
*
* For example,
* "-1230k" will be converted to -1230 * 1024 = -1259520;
* "891g" will be converted to 891 * 1024^3 = 956703965184;
*
* @param s input string
* @return a long value represented by the input string.
*/
public static long string2long(String s) {
s = s.trim();
final int lastpos = s.length() - 1;
final char lastchar = s.charAt(lastpos);
if (Character.isDigit(lastchar))
return Long.parseLong(s);
else {
long prefix = TraditionalBinaryPrefix.valueOf(lastchar).value;
long num = Long.parseLong(s.substring(0, lastpos));
if (num > (Long.MAX_VALUE / prefix) || num < (Long.MIN_VALUE / prefix)) {
throw new IllegalArgumentException(s + " does not fit in a Long");
}
return num * prefix;
}
}
}
/**
* Escapes HTML Special characters present in the string.
* @param string
* @return HTML Escaped String representation
*/
public static String escapeHTML(String string) {
if (string == null) {
return null;
}
StringBuilder sb = new StringBuilder();
boolean lastCharacterWasSpace = false;
char[] chars = string.toCharArray();
for (char c : chars) {
if (c == ' ') {
if (lastCharacterWasSpace) {
lastCharacterWasSpace = false;
sb.append(" ");
} else {
lastCharacterWasSpace = true;
sb.append(" ");
}
} else {
lastCharacterWasSpace = false;
switch (c) {
case '<':
sb.append("<");
break;
case '>':
sb.append(">");
break;
case '&':
sb.append("&");
break;
case '"':
sb.append(""");
break;
default:
sb.append(c);
break;
}
}
}
return sb.toString();
}
/**
* Return an abbreviated English-language desc of the byte length
*/
public static String byteDesc(long len) {
double val;
String ending;
if (len < 1024 * 1024) {
val = (1.0 * len) / 1024;
ending = " KB";
} else if (len < 1024 * 1024 * 1024) {
val = (1.0 * len) / (1024 * 1024);
ending = " MB";
} else if (len < 1024L * 1024 * 1024 * 1024) {
val = (1.0 * len) / (1024 * 1024 * 1024);
ending = " GB";
} else if (len < 1024L * 1024 * 1024 * 1024 * 1024) {
val = (1.0 * len) / (1024L * 1024 * 1024 * 1024);
ending = " TB";
} else {
val = (1.0 * len) / (1024L * 1024 * 1024 * 1024 * 1024);
ending = " PB";
}
return limitDecimalTo2(val) + ending;
}
public static synchronized String limitDecimalTo2(double d) {
return decimalFormat.format(d);
}
/**
* Concatenates strings, using a separator.
*
* @param separator Separator to join with.
* @param strings Strings to join.
*/
public static String join(CharSequence separator, Iterable strings) {
StringBuilder sb = new StringBuilder();
boolean first = true;
for (String s : strings) {
if (first) {
first = false;
} else {
sb.append(separator);
}
sb.append(s);
}
return sb.toString();
}
/**
* Concatenates stringified objects, using a separator.
*
* @param separator Separator to join with.
* @param objects Objects to join.
*/
public static String joinObjects(CharSequence separator, Iterable objects) {
StringBuilder sb = new StringBuilder();
boolean first = true;
for (Object o : objects) {
if (first) {
first = false;
} else {
sb.append(separator);
}
sb.append(String.valueOf(o));
}
return sb.toString();
}
}
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