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// ***************************************************************************************************************************
// * Licensed to the Apache Software Foundation (ASF) under one or more contributor license agreements. See the NOTICE file *
// * distributed with this work for additional information regarding copyright ownership. The ASF licenses this file *
// * to you 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.apache.juneau.common.internal;
import static org.apache.juneau.common.internal.ArgUtils.*;
import static org.apache.juneau.common.internal.IOUtils.*;
import static org.apache.juneau.common.internal.ThrowableUtils.*;
import java.io.*;
import java.lang.reflect.*;
import java.math.*;
import java.net.*;
import java.nio.*;
import java.nio.charset.*;
import java.text.*;
import java.util.*;
import java.util.concurrent.*;
import java.util.concurrent.atomic.*;
import java.util.function.*;
import java.util.regex.*;
import java.util.stream.*;
import java.util.zip.*;
import javax.xml.bind.*;
/**
* Reusable string utility methods.
*/
public final class StringUtils {
/**
* Predicate check to filter out null and empty strings.
*/
public static final Predicate NOT_EMPTY = StringUtils::isNotEmpty;
private static final AsciiSet numberChars = AsciiSet.create("-xX.+-#pP0123456789abcdefABCDEF");
private static final AsciiSet firstNumberChars =AsciiSet.create("+-.#0123456789");
private static final AsciiSet octChars = AsciiSet.create("01234567");
private static final AsciiSet decChars = AsciiSet.create("0123456789");
private static final AsciiSet hexChars = AsciiSet.create("0123456789abcdefABCDEF");
// Maps 6-bit nibbles to BASE64 characters.
private static final char[] base64m1 = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/".toCharArray();
// Characters that do not need to be URL-encoded
private static final AsciiSet unencodedChars = AsciiSet.create().ranges("a-z","A-Z","0-9").chars("-_.!~*'()\\").build();
// Characters that really do not need to be URL-encoded
private static final AsciiSet unencodedCharsLax = unencodedChars.copy()
.chars(":@$,") // reserved, but can't be confused in a query parameter.
.chars("{}|\\^[]`") // unwise characters.
.build();
// Valid HTTP header characters (including quoted strings and comments).
private static final AsciiSet httpHeaderChars = AsciiSet
.create()
.chars("\t -")
.ranges("!-[","]-}")
.build();
// Maps BASE64 characters to 6-bit nibbles.
private static final byte[] base64m2 = new byte[128];
static {
for (int i = 0; i < 64; i++)
base64m2[base64m1[i]] = (byte)i;
}
/**
* Parses a number from the specified string.
*
* @param s The string to parse the number from.
* @param type
* The number type to created.
* Can be any of the following:
*
* - Integer
*
- Double
*
- Float
*
- Long
*
- Short
*
- Byte
*
- BigInteger
*
- BigDecimal
*
* If null or Number , uses the best guess.
* @return The parsed number, or null if the string was null.
*/
public static Number parseNumber(String s, Class extends Number> type) {
if (s == null)
return null;
if (s.isEmpty())
s = "0";
if (type == null)
type = Number.class;
// Determine the data type if it wasn't specified.
boolean isAutoDetect = (type == Number.class);
boolean isDecimal = false;
if (isAutoDetect) {
// If we're auto-detecting, then we use either an Integer, Long, or Double depending on how
// long the string is.
// An integer range is -2,147,483,648 to 2,147,483,647
// An long range is -9,223,372,036,854,775,808 to +9,223,372,036,854,775,807
isDecimal = isDecimal(s);
if (isDecimal) {
if (s.length() > 20)
type = Double.class;
else if (s.length() >= 10)
type = Long.class;
else
type = Integer.class;
}
else if (isFloat(s))
type = Double.class;
else
throw new NumberFormatException(s);
}
if (type == Double.class || type == Double.TYPE) {
Double d = Double.valueOf(s);
Float f = Float.valueOf(s);
if (isAutoDetect && (!isDecimal) && d.toString().equals(f.toString()))
return f;
return d;
}
if (type == Float.class || type == Float.TYPE)
return Float.valueOf(s);
if (type == BigDecimal.class)
return new BigDecimal(s);
if (type == Long.class || type == Long.TYPE || type == AtomicLong.class) {
try {
Long l = Long.decode(s);
if (type == AtomicLong.class)
return new AtomicLong(l);
if (isAutoDetect && l >= Integer.MIN_VALUE && l <= Integer.MAX_VALUE) {
// This occurs if the string is 10 characters long but is still a valid integer value.
return l.intValue();
}
return l;
} catch (NumberFormatException e) {
if (isAutoDetect) {
// This occurs if the string is 20 characters long but still falls outside the range of a valid long.
return Double.valueOf(s);
}
throw e;
}
}
if (type == Integer.class || type == Integer.TYPE)
return Integer.decode(s);
if (type == Short.class || type == Short.TYPE)
return Short.decode(s);
if (type == Byte.class || type == Byte.TYPE)
return Byte.decode(s);
if (type == BigInteger.class)
return new BigInteger(s);
if (type == AtomicInteger.class)
return new AtomicInteger(Integer.decode(s));
throw new NumberFormatException("Unsupported Number type: "+type.getName());
}
private static final Pattern fpRegex = Pattern.compile(
"[+-]?(NaN|Infinity|((((\\p{Digit}+)(\\.)?((\\p{Digit}+)?)([eE][+-]?(\\p{Digit}+))?)|(\\.((\\p{Digit}+))([eE][+-]?(\\p{Digit}+))?)|(((0[xX](\\p{XDigit}+)(\\.)?)|(0[xX](\\p{XDigit}+)?(\\.)(\\p{XDigit}+)))[pP][+-]?(\\p{Digit}+)))[fFdD]?))[\\x00-\\x20]*"
);
/**
* Converts a String to a Character
*
* @param o The string to convert.
* @return The first character of the string if the string is of length 0, or null if the string is null or empty.
*/
public static Character parseCharacter(Object o) {
if (o == null)
return null;
String s = o.toString();
if (s.isEmpty())
return null;
if (s.length() == 1)
return s.charAt(0);
throw new IllegalArgumentException("Invalid character: '" + s + "'");
}
/**
* Returns true if this string can be parsed by {@link #parseNumber(String, Class)}.
*
* @param s The string to check.
* @return true if this string can be parsed without causing an exception.
*/
public static boolean isNumeric(String s) {
if (s == null || s.isEmpty() || ! isFirstNumberChar(s.charAt(0)))
return false;
return isDecimal(s) || isFloat(s);
}
/**
* Returns true if the specified character is a valid first character for a number.
*
* @param c The character to test.
* @return true if the specified character is a valid first character for a number.
*/
public static boolean isFirstNumberChar(char c) {
return firstNumberChars.contains(c);
}
/**
* Returns true if the specified string is a floating point number.
*
* @param s The string to check.
* @return true if the specified string is a floating point number.
*/
public static boolean isFloat(String s) {
if (s == null || s.isEmpty())
return false;
if (! firstNumberChars.contains(s.charAt(0)))
return (s.equals("NaN") || s.equals("Infinity"));
int i = 0;
int length = s.length();
char c = s.charAt(0);
if (c == '+' || c == '-')
i++;
if (i == length)
return false;
c = s.charAt(i++);
if (c == '.' || decChars.contains(c)) {
return fpRegex.matcher(s).matches();
}
return false;
}
/**
* Returns true if the specified string is numeric.
*
* @param s The string to check.
* @return true if the specified string is numeric.
*/
public static boolean isDecimal(String s) {
if (s == null || s.isEmpty() || ! firstNumberChars.contains(s.charAt(0)))
return false;
int i = 0;
int length = s.length();
char c = s.charAt(0);
boolean isPrefixed = false;
if (c == '+' || c == '-') {
isPrefixed = true;
i++;
}
if (i == length)
return false;
c = s.charAt(i++);
if (c == '0' && length > (isPrefixed ? 2 : 1)) {
c = s.charAt(i++);
if (c == 'x' || c == 'X') {
for (int j = i; j < length; j++) {
if (! hexChars.contains(s.charAt(j)))
return false;
}
} else if (octChars.contains(c)) {
for (int j = i; j < length; j++)
if (! octChars.contains(s.charAt(j)))
return false;
} else {
return false;
}
} else if (c == '#') {
for (int j = i; j < length; j++) {
if (! hexChars.contains(s.charAt(j)))
return false;
}
} else if (decChars.contains(c)) {
for (int j = i; j < length; j++)
if (! decChars.contains(s.charAt(j)))
return false;
} else {
return false;
}
return true;
}
/**
* Join the specified tokens into a delimited string.
*
* @param tokens The tokens to join.
* @param separator The delimiter.
* @return The delimited string. If tokens is null , returns null .
*/
public static String join(Object[] tokens, String separator) {
if (tokens == null)
return null;
StringBuilder sb = new StringBuilder();
for (int i = 0; i < tokens.length; i++) {
if (i > 0)
sb.append(separator);
sb.append(tokens[i]);
}
return sb.toString();
}
/**
* Join the specified tokens into a delimited string.
*
* @param tokens The tokens to join.
* @param d The delimiter.
* @return The delimited string. If tokens is null , returns null .
*/
public static String join(Collection> tokens, String d) {
if (tokens == null)
return null;
return join(tokens, d, new StringBuilder()).toString();
}
/**
* Join the specified tokens into a delimited string.
*
* @param tokens The tokens to join.
* @param d The delimiter.
* @return The delimited string. If tokens is null , returns null .
*/
public static String join(List> tokens, String d) {
if (tokens == null)
return null;
return join(tokens, d, new StringBuilder()).toString();
}
/**
* Joins the specified tokens into a delimited string and writes the output to the specified string builder.
*
* @param tokens The tokens to join.
* @param d The delimiter.
* @param sb The string builder to append the response to.
* @return The same string builder passed in as sb .
*/
public static StringBuilder join(Collection> tokens, String d, StringBuilder sb) {
if (tokens == null)
return sb;
for (Iterator> iter = tokens.iterator(); iter.hasNext();) {
sb.append(iter.next());
if (iter.hasNext())
sb.append(d);
}
return sb;
}
/**
* Joins the specified tokens into a delimited string and writes the output to the specified string builder.
*
* @param tokens The tokens to join.
* @param d The delimiter.
* @param sb The string builder to append the response to.
* @return The same string builder passed in as sb .
*/
public static StringBuilder join(List> tokens, String d, StringBuilder sb) {
if (tokens == null)
return sb;
for (int i = 0, j = tokens.size(); i < j; i++) {
if (i > 0)
sb.append(d);
sb.append(tokens.get(i));
}
return sb;
}
/**
* Joins the specified tokens into a delimited string.
*
* @param tokens The tokens to join.
* @param d The delimiter.
* @return The delimited string. If tokens is null , returns null .
*/
public static String join(Object[] tokens, char d) {
if (tokens == null)
return null;
if (tokens.length == 1)
return emptyIfNull(stringify(tokens[0]));
return join(tokens, d, new StringBuilder()).toString();
}
private static AsciiSet getEscapeSet(char c) {
AsciiSet s = ESCAPE_SETS.get(c);
if (s == null) {
s = AsciiSet.create().chars(c, '\\').build();
ESCAPE_SETS.put(c, s);
}
return s;
}
static Map ESCAPE_SETS = new ConcurrentHashMap<>();
/**
* Join the specified tokens into a delimited string and writes the output to the specified string builder.
*
* @param tokens The tokens to join.
* @param d The delimiter.
* @param sb The string builder to append the response to.
* @return The same string builder passed in as sb .
*/
public static StringBuilder join(Object[] tokens, char d, StringBuilder sb) {
if (tokens == null)
return sb;
for (int i = 0; i < tokens.length; i++) {
if (i > 0)
sb.append(d);
sb.append(tokens[i]);
}
return sb;
}
/**
* Join the specified tokens into a delimited string.
*
* @param tokens The tokens to join.
* @param d The delimiter.
* @return The delimited string. If tokens is null , returns null .
*/
public static String join(int[] tokens, char d) {
if (tokens == null)
return null;
StringBuilder sb = new StringBuilder();
for (int i = 0; i < tokens.length; i++) {
if (i > 0)
sb.append(d);
sb.append(tokens[i]);
}
return sb.toString();
}
/**
* Join the specified tokens into a delimited string.
*
* @param tokens The tokens to join.
* @param d The delimiter.
* @return The delimited string. If tokens is null , returns null .
*/
public static String join(Collection> tokens, char d) {
if (tokens == null)
return null;
StringBuilder sb = new StringBuilder();
for (Iterator> iter = tokens.iterator(); iter.hasNext();) {
sb.append(iter.next());
if (iter.hasNext())
sb.append(d);
}
return sb.toString();
}
/**
* Join the specified tokens into a delimited string.
*
* @param tokens The tokens to join.
* @param d The delimiter.
* @return The delimited string. If tokens is null , returns null .
*/
public static String join(List> tokens, char d) {
if (tokens == null)
return null;
StringBuilder sb = new StringBuilder();
for (int i = 0, j = tokens.size(); i < j; i++) {
if (i > 0)
sb.append(d);
sb.append(tokens.get(i));
}
return sb.toString();
}
/**
* Same as {@link #join(Collection, char)} but escapes the delimiter if found in the tokens.
*
* @param tokens The tokens to join.
* @param d The delimiter.
* @return The delimited string. If tokens is null , returns null .
*/
public static String joine(List> tokens, char d) {
if (tokens == null)
return null;
AsciiSet as = getEscapeSet(d);
StringBuilder sb = new StringBuilder();
for (int i = 0, j = tokens.size(); i < j; i++) {
if (i > 0)
sb.append(d);
sb.append(escapeChars(stringify(tokens.get(i)), as));
}
return sb.toString();
}
/**
* Joins tokens with newlines.
*
* @param tokens The tokens to concatenate.
* @return A string with the specified tokens contatenated with newlines.
*/
public static String joinnl(Object[] tokens) {
return join(tokens, '\n');
}
/**
* Shortcut for calling split(s, ',' )
*
* @param s The string to split. Can be null .
* @return The tokens, or null if the string was null.
*/
public static String[] split(String s) {
return split(s, ',');
}
/**
* Same as {@link #split(String)} but consumes the tokens instead of creating an array.
*
* @param s The string to split.
* @param consumer The consumer of the tokens.
*/
public static void split(String s, Consumer consumer) {
split(s, ',', consumer);
}
/**
* Splits a character-delimited string into a string array.
*
*
* Does not split on escaped-delimiters (e.g. "\,");
* Resulting tokens are trimmed of whitespace.
*
*
* NOTE: This behavior is different than the Jakarta equivalent.
* split("a,b,c",',') -> {"a","b","c"}
* split("a, b ,c ",',') -> {"a","b","c"}
* split("a,,c",',') -> {"a","","c"}
* split(",,",',') -> {"","",""}
* split("",',') -> {}
* split(null,',') -> null
* split("a,b\,c,d", ',', false) -> {"a","b\,c","d"}
* split("a,b\\,c,d", ',', false) -> {"a","b\","c","d"}
* split("a,b\,c,d", ',', true) -> {"a","b,c","d"}
*
* @param s The string to split. Can be null .
* @param c The character to split on.
* @return The tokens, or null if the string was null.
*/
public static String[] split(String s, char c) {
return split(s, c, Integer.MAX_VALUE);
}
/**
* Same as {@link #split(String,char)} but consumes the tokens instead of creating an array.
*
* @param s The string to split.
* @param c The character to split on.
* @param consumer The consumer of the tokens.
*/
public static void split(String s, char c, Consumer consumer) {
AsciiSet escapeChars = getEscapeSet(c);
if (isEmpty(s))
return;
if (s.indexOf(c) == -1) {
consumer.accept(s);
return;
}
int x1 = 0, escapeCount = 0;
for (int i = 0; i < s.length(); i++) {
if (s.charAt(i) == '\\')
escapeCount++;
else if (s.charAt(i)==c && escapeCount % 2 == 0) {
String s2 = s.substring(x1, i);
String s3 = unEscapeChars(s2, escapeChars);
consumer.accept(s3.trim());
x1 = i+1;
}
if (s.charAt(i) != '\\')
escapeCount = 0;
}
String s2 = s.substring(x1);
String s3 = unEscapeChars(s2, escapeChars);
consumer.accept(s3.trim());
}
/**
* Same as {@link #split(String, char)} but limits the number of tokens returned.
*
* @param s The string to split. Can be null .
* @param c The character to split on.
* @param limit The maximum number of tokens to return.
* @return The tokens, or null if the string was null.
*/
public static String[] split(String s, char c, int limit) {
AsciiSet escapeChars = getEscapeSet(c);
if (s == null)
return null;
if (isEmpty(s))
return new String[0];
if (s.indexOf(c) == -1)
return new String[]{s};
List l = new LinkedList<>();
char[] sArray = s.toCharArray();
int x1 = 0, escapeCount = 0;
limit--;
for (int i = 0; i < sArray.length && limit > 0; i++) {
if (sArray[i] == '\\')
escapeCount++;
else if (sArray[i]==c && escapeCount % 2 == 0) {
String s2 = new String(sArray, x1, i-x1);
String s3 = unEscapeChars(s2, escapeChars);
l.add(s3.trim());
limit--;
x1 = i+1;
}
if (sArray[i] != '\\')
escapeCount = 0;
}
String s2 = new String(sArray, x1, sArray.length-x1);
String s3 = unEscapeChars(s2, escapeChars);
l.add(s3.trim());
return l.toArray(new String[l.size()]);
}
/**
* Same as {@link #split(String, char)} except splits all strings in the input and returns a single result.
*
* @param s The string to split. Can be null .
* @param c The character to split on.
* @return The tokens.
*/
public static String[] split(String[] s, char c) {
if (s == null)
return null;
List l = new LinkedList<>();
for (String ss : s) {
if (ss == null || ss.indexOf(c) == -1)
l.add(ss);
else
Collections.addAll(l, split(ss, c));
}
return l.toArray(new String[l.size()]);
}
/**
* Splits a list of key-value pairs into an ordered map.
*
*
* Example:
*
* String in = "foo=1;bar=2" ;
* Map map = StringUtils.splitMap (in, ';' , '=' , true );
*
*
* @param s The string to split.
* @param trim Trim strings after parsing.
* @return The parsed map. Never null .
*/
public static Map splitMap(String s, boolean trim) {
if (s == null)
return null;
if (isEmpty(s))
return Collections.emptyMap();
Map m = new LinkedHashMap<>();
int
S1 = 1, // Found start of key, looking for equals.
S2 = 2; // Found equals, looking for delimiter (or end).
int state = S1;
char[] sArray = s.toCharArray();
int x1 = 0, escapeCount = 0;
String key = null;
for (int i = 0; i < sArray.length + 1; i++) {
char c = i == sArray.length ? ',' : sArray[i];
if (c == '\\')
escapeCount++;
if (escapeCount % 2 == 0) {
if (state == S1) {
if (c == '=') {
key = s.substring(x1, i);
if (trim)
key = trim(key);
key = unEscapeChars(key, MAP_ESCAPE_SET);
state = S2;
x1 = i+1;
} else if (c == ',') {
key = s.substring(x1, i);
if (trim)
key = trim(key);
key = unEscapeChars(key, MAP_ESCAPE_SET);
m.put(key, "");
state = S1;
x1 = i+1;
}
} else if (state == S2) {
if (c == ',') {
String val = s.substring(x1, i);
if (trim)
val = trim(val);
val = unEscapeChars(val, MAP_ESCAPE_SET);
m.put(key, val);
key = null;
x1 = i+1;
state = S1;
}
}
}
if (c != '\\')
escapeCount = 0;
}
return m;
}
private static final AsciiSet MAP_ESCAPE_SET = AsciiSet.create(",=\\");
/**
* Returns true if the specified string contains any of the specified characters.
*
* @param s The string to test.
* @param chars The characters to look for.
* @return
* true if the specified string contains any of the specified characters.
*
false if the string is null .
*/
public static boolean containsAny(String s, char...chars) {
if (s == null)
return false;
for (int i = 0, j = s.length(); i < j; i++) {
char c = s.charAt(i);
for (char c2 : chars)
if (c == c2)
return true;
}
return false;
}
/**
* Splits a space-delimited string with optionally quoted arguments.
*
*
* Examples:
*
* "foo" => ["foo"]
* " foo " => ["foo"]
* "foo bar baz" => ["foo","bar","baz"]
* "foo 'bar baz'" => ["foo","bar baz"]
* "foo \"bar baz\"" => ["foo","bar baz"]
* "foo 'bar\'baz'" => ["foo","bar'baz"]
*
*
* @param s The input string.
* @return
* The results, or null if the input was null .
*
An empty string results in an empty array.
*/
public static String[] splitQuoted(String s) {
return splitQuoted(s, false);
}
/**
* Same as {@link #splitQuoted(String)} but allows you to optionally keep the quote characters.
*
* @param s The input string.
* @param keepQuotes If true , quote characters are kept on the tokens.
* @return
* The results, or null if the input was null .
*
An empty string results in an empty array.
*/
public static String[] splitQuoted(String s, boolean keepQuotes) {
if (s == null)
return null;
s = s.trim();
if (isEmpty(s))
return new String[0];
if (! containsAny(s, ' ', '\t', '\'', '"'))
return new String[]{s};
int
S1 = 1, // Looking for start of token.
S2 = 2, // Found ', looking for end '
S3 = 3, // Found ", looking for end "
S4 = 4; // Found non-whitespace, looking for end whitespace.
int state = S1;
boolean isInEscape = false, needsUnescape = false;
int mark = 0;
List l = new ArrayList<>();
for (int i = 0; i < s.length(); i++) {
char c = s.charAt(i);
if (state == S1) {
if (c == '\'') {
state = S2;
mark = keepQuotes ? i : i+1;
} else if (c == '"') {
state = S3;
mark = keepQuotes ? i : i+1;
} else if (c != ' ' && c != '\t') {
state = S4;
mark = i;
}
} else if (state == S2 || state == S3) {
if (c == '\\') {
isInEscape = ! isInEscape;
needsUnescape = ! keepQuotes;
} else if (! isInEscape) {
if (c == (state == S2 ? '\'' : '"')) {
String s2 = s.substring(mark, keepQuotes ? i+1 : i);
if (needsUnescape)
s2 = unEscapeChars(s2, QUOTE_ESCAPE_SET);
l.add(s2);
state = S1;
isInEscape = needsUnescape = false;
}
} else {
isInEscape = false;
}
} else if (state == S4) {
if (c == ' ' || c == '\t') {
l.add(s.substring(mark, i));
state = S1;
}
}
}
if (state == S4)
l.add(s.substring(mark));
else if (state == S2 || state == S3)
throw new IllegalArgumentException("Unmatched string quotes: " + s);
return l.toArray(new String[l.size()]);
}
private static final AsciiSet QUOTE_ESCAPE_SET = AsciiSet.create("\"'\\");
/**
* Returns true if specified string is null or empty.
*
* @param s The string to check.
* @return true if specified string is null or empty.
*/
public static boolean isEmpty(String s) {
return s == null || s.isEmpty();
}
/**
* Returns true if specified charsequence is null or empty.
*
* @param s The string to check.
* @return true if specified charsequence is null or empty.
*/
public static boolean isEmpty(CharSequence s) {
return s == null || s.length() == 0;
}
/**
* Returns true if specified string is null or empty or consists of only blanks.
*
* @param s The string to check.
* @return true if specified string is null or emptyor consists of only blanks.
*/
public static boolean isEmptyOrBlank(String s) {
return s == null || s.trim().isEmpty();
}
/**
* Returns true if specified string is not null or empty.
*
* @param s The string to check.
* @return true if specified string is not null or empty.
*/
public static boolean isNotEmpty(String s) {
return ! isEmpty(s);
}
/**
* Returns true if either of the specified strings are not null or empty.
*
* @param s1 The string to check.
* @param s2 The string to check.
* @return true if either of the specified strings are not null or empty.
*/
public static boolean isNotEmpty(String s1, String s2) {
return isNotEmpty(s1) || isNotEmpty(s2);
}
/**
* Returns null if the specified string is null or empty.
*
* @param s The string to check.
* @return null if the specified string is null or empty, or the same string if not.
*/
public static String nullIfEmpty(String s) {
if (s == null || s.isEmpty())
return null;
return s;
}
/**
* Returns an empty string if the specified string is null .
*
* @param s The string to check.
* @return An empty string if the specified string is null , or the same string otherwise.
*/
public static String emptyIfNull(String s) {
if (s == null)
return "";
return s;
}
/**
* Returns an empty string if the specified object is null .
*
* @param o The object to check.
* @return An empty string if the specified object is null , or the object converted to a string using {@link String#toString()}.
*/
public static String emptyIfNull(Object o) {
if (o == null)
return "";
return o.toString();
}
/**
* Removes escape characters from the specified characters.
*
* @param s The string to remove escape characters from.
* @param escaped The characters escaped.
* @return A new string if characters were removed, or the same string if not or if the input was null .
*/
public static String unEscapeChars(String s, AsciiSet escaped) {
if (s == null || s.isEmpty())
return s;
int count = 0;
for (int i = 0; i < s.length(); i++)
if (escaped.contains(s.charAt(i)))
count++;
if (count == 0)
return s;
StringBuffer sb = new StringBuffer(s.length()-count);
for (int i = 0; i < s.length(); i++) {
char c = s.charAt(i);
if (c == '\\') {
if (i+1 != s.length()) {
char c2 = s.charAt(i+1);
if (escaped.contains(c2)) {
i++;
} else if (c2 == '\\') {
sb.append('\\');
i++;
}
}
}
sb.append(s.charAt(i));
}
return sb.toString();
}
/**
* Escapes the specified characters in the string.
*
* @param s The string with characters to escape.
* @param escaped The characters to escape.
* @return The string with characters escaped, or the same string if no escapable characters were found.
*/
public static String escapeChars(String s, AsciiSet escaped) {
if (s == null || s.length() == 0)
return s;
int count = 0;
for (int i = 0; i < s.length(); i++)
if (escaped.contains(s.charAt(i)))
count++;
if (count == 0)
return s;
StringBuffer sb = new StringBuffer(s.length() + count);
for (int i = 0; i < s.length(); i++) {
char c = s.charAt(i);
if (escaped.contains(c))
sb.append('\\');
sb.append(c);
}
return sb.toString();
}
/**
* Debug method for rendering non-ASCII character sequences.
*
* @param s The string to decode.
* @return A string with non-ASCII characters converted to "[hex]" sequences.
*/
public static String decodeHex(String s) {
if (s == null)
return null;
StringBuilder sb = new StringBuilder();
for (char c : s.toCharArray()) {
if (c < ' ' || c > '~')
sb.append("["+Integer.toHexString(c)+"]");
else
sb.append(c);
}
return sb.toString();
}
/**
* An efficient method for checking if a string starts with a character.
*
* @param s The string to check. Can be null .
* @param c The character to check for.
* @return true if the specified string is not null and starts with the specified character.
*/
public static boolean startsWith(String s, char c) {
if (s != null) {
int i = s.length();
if (i > 0)
return s.charAt(0) == c;
}
return false;
}
/**
* An efficient method for checking if a string ends with a character.
*
* @param s The string to check. Can be null .
* @param c The character to check for.
* @return true if the specified string is not null and ends with the specified character.
*/
public static boolean endsWith(String s, char c) {
if (s != null) {
int i = s.length();
if (i > 0)
return s.charAt(i-1) == c;
}
return false;
}
/**
* Same as {@link #endsWith(String, char)} except check for multiple characters.
*
* @param s The string to check. Can be null .
* @param c The characters to check for.
* @return true if the specified string is not null and ends with the specified character.
*/
public static boolean endsWith(String s, char...c) {
if (s != null) {
int i = s.length();
if (i > 0) {
char c2 = s.charAt(i-1);
for (char cc : c)
if (c2 == cc)
return true;
}
}
return false;
}
/**
* Converts the specified number into a 2 hexadecimal characters.
*
* @param num The number to convert to hex.
* @return A char [2]
containing the specified characters.
*/
public static char[] toHex2(int num) {
if (num < 0 || num > 255)
throw new NumberFormatException("toHex2 can only be used on numbers between 0 and 255");
char[] n = new char[2];
int a = num%16;
n[1] = (char)(a > 9 ? 'A'+a-10 : '0'+a);
a = (num/16)%16;
n[0] = (char)(a > 9 ? 'A'+a-10 : '0'+a);
return n;
}
private final static char[] hexArray = "0123456789ABCDEF".toCharArray();
/**
* Converts the specified byte into a 2 hexadecimal characters.
*
* @param b The number to convert to hex.
* @return A char [2]
containing the specified characters.
*/
public static String toHex(byte b) {
char[] c = new char[2];
int v = b & 0xFF;
c[0] = hexArray[v >>> 4];
c[1] = hexArray[v & 0x0F];
return new String(c);
}
/**
* Converts the specified bytes into a readable string.
*
* @param b The number to convert to hex.
* @return A char [2]
containing the specified characters.
*/
public static String toReadableBytes(byte[] b) {
StringBuilder sb = new StringBuilder();
for (byte b2 : b)
sb.append((b2 < ' ' || b2 > 'z') ? String.format("[%02X]", b2) : (char)b2 + " ");
sb.append("\n");
for (byte b2 : b)
sb.append(String.format("[%02X]", b2));
return sb.toString();
}
/**
* Converts the specified number into a 4 hexadecimal characters.
*
* @param num The number to convert to hex.
* @return A char [4]
containing the specified characters.
*/
public static char[] toHex4(int num) {
char[] n = new char[4];
int a = num%16;
n[3] = (char)(a > 9 ? 'A'+a-10 : '0'+a);
int base = 16;
for (int i = 1; i < 4; i++) {
a = (num/base)%16;
base <<= 4;
n[3-i] = (char)(a > 9 ? 'A'+a-10 : '0'+a);
}
return n;
}
/**
* Converts the specified number into a 8 hexadecimal characters.
*
* @param num The number to convert to hex.
* @return A char [8]
containing the specified characters.
*/
public static char[] toHex8(long num) {
char[] n = new char[8];
long a = num%16;
n[7] = (char)(a > 9 ? 'A'+a-10 : '0'+a);
int base = 16;
for (int i = 1; i < 8; i++) {
a = (num/base)%16;
base <<= 4;
n[7-i] = (char)(a > 9 ? 'A'+a-10 : '0'+a);
}
return n;
}
/**
* Tests two strings for equality, but gracefully handles nulls.
*
* @param s1 String 1.
* @param s2 String 2.
* @return true if the strings are equal.
*/
public static boolean eq(String s1, String s2) {
if (s1 == null)
return s2 == null;
if (s2 == null)
return false;
return s1.equals(s2);
}
/**
* Tests two strings for equality, but gracefully handles nulls.
*
* @param caseInsensitive Use case-insensitive matching.
* @param s1 String 1.
* @param s2 String 2.
* @return true if the strings are equal.
*/
public static boolean eq(boolean caseInsensitive, String s1, String s2) {
return caseInsensitive ? eqic(s1, s2) : eq(s1, s2);
}
/**
* Finds the position where the two strings differ.
*
* @param s1 The first string.
* @param s2 The second string.
* @return The position where the two strings differ, or -1 if they're equal.
*/
public static int diffPosition(String s1, String s2) {
s1 = emptyIfNull(s1);
s2 = emptyIfNull(s2);
int i = 0;
int len = Math.min(s1.length(), s2.length());
while (i < len) {
int j = s1.charAt(i) - s2.charAt(i);
if (j != 0)
return i;
i++;
}
if (i == len && s1.length() == s2.length())
return -1;
return i;
}
/**
* Finds the position where the two strings differ ignoring case.
*
* @param s1 The first string.
* @param s2 The second string.
* @return The position where the two strings differ, or -1 if they're equal.
*/
public static int diffPositionIc(String s1, String s2) {
s1 = emptyIfNull(s1);
s2 = emptyIfNull(s2);
int i = 0;
int len = Math.min(s1.length(), s2.length());
while (i < len) {
int j = Character.toLowerCase(s1.charAt(i)) - Character.toLowerCase(s2.charAt(i));
if (j != 0)
return i;
i++;
}
if (i == len && s1.length() == s2.length())
return -1;
return i;
}
/**
* Tests two strings for case-insensitive equality, but gracefully handles nulls.
*
* @param s1 String 1.
* @param s2 String 2.
* @return true if the strings are equal.
*/
public static boolean eqic(String s1, String s2) {
if (s1 == null)
return s2 == null;
if (s2 == null)
return false;
return s1.equalsIgnoreCase(s2);
}
/**
* Tests two strings for non-equality, but gracefully handles nulls.
*
* @param s1 String 1.
* @param s2 String 2.
* @return true if the strings are not equal.
*/
public static boolean ne(String s1, String s2) {
return ! eq(s1, s2);
}
/**
* Tests two strings for non-equality ignoring case, but gracefully handles nulls.
*
* @param s1 String 1.
* @param s2 String 2.
* @return true if the strings are not equal ignoring case.
*/
public static boolean neic(String s1, String s2) {
return ! eqic(s1, s2);
}
/**
* Shortcut for calling base64Encode(in.getBytes("UTF-8" ))
*
* @param in The input string to convert.
* @return The string converted to BASE-64 encoding.
*/
public static String base64EncodeToString(String in) {
if (in == null)
return null;
return base64Encode(in.getBytes(IOUtils.UTF8));
}
/**
* BASE64-encodes the specified byte array.
*
* @param in The input byte array to convert.
* @return The byte array converted to a BASE-64 encoded string.
*/
public static String base64Encode(byte[] in) {
if (in == null)
return null;
int outLength = (in.length * 4 + 2) / 3; // Output length without padding
char[] out = new char[((in.length + 2) / 3) * 4]; // Length includes padding.
int iIn = 0;
int iOut = 0;
while (iIn < in.length) {
int i0 = in[iIn++] & 0xff;
int i1 = iIn < in.length ? in[iIn++] & 0xff : 0;
int i2 = iIn < in.length ? in[iIn++] & 0xff : 0;
int o0 = i0 >>> 2;
int o1 = ((i0 & 3) << 4) | (i1 >>> 4);
int o2 = ((i1 & 0xf) << 2) | (i2 >>> 6);
int o3 = i2 & 0x3F;
out[iOut++] = base64m1[o0];
out[iOut++] = base64m1[o1];
out[iOut] = iOut < outLength ? base64m1[o2] : '=';
iOut++;
out[iOut] = iOut < outLength ? base64m1[o3] : '=';
iOut++;
}
return new String(out);
}
/**
* Shortcut for calling base64Decode(String) and converting the result to a UTF-8 encoded string.
*
* @param in The BASE-64 encoded string to decode.
* @return The decoded string.
*/
public static String base64DecodeToString(String in) {
byte[] b = base64Decode(in);
if (b == null)
return null;
return new String(b, IOUtils.UTF8);
}
/**
* BASE64-decodes the specified string.
*
* @param in The BASE-64 encoded string.
* @return The decoded byte array.
*/
public static byte[] base64Decode(String in) {
if (in == null)
return null;
byte bIn[] = in.getBytes(IOUtils.UTF8);
assertArg(bIn.length % 4 == 0, "Invalid BASE64 string length. Must be multiple of 4.");
// Strip out any trailing '=' filler characters.
int inLength = bIn.length;
while (inLength > 0 && bIn[inLength - 1] == '=')
inLength--;
int outLength = (inLength * 3) / 4;
byte[] out = new byte[outLength];
int iIn = 0;
int iOut = 0;
while (iIn < inLength) {
int i0 = bIn[iIn++];
int i1 = bIn[iIn++];
int i2 = iIn < inLength ? bIn[iIn++] : 'A';
int i3 = iIn < inLength ? bIn[iIn++] : 'A';
int b0 = base64m2[i0];
int b1 = base64m2[i1];
int b2 = base64m2[i2];
int b3 = base64m2[i3];
int o0 = (b0 << 2) | (b1 >>> 4);
int o1 = ((b1 & 0xf) << 4) | (b2 >>> 2);
int o2 = ((b2 & 3) << 6) | b3;
out[iOut++] = (byte)o0;
if (iOut < outLength)
out[iOut++] = (byte)o1;
if (iOut < outLength)
out[iOut++] = (byte)o2;
}
return out;
}
/**
* Generated a random UUID with the specified number of characters.
*
*
* Characters are composed of lower-case ASCII letters and numbers only.
*
*
* This method conforms to the restrictions for hostnames as specified in RFC 952
* Since each character has 36 possible values, the square approximation formula for the number of generated IDs
* that would produce a 50% chance of collision is:
* sqrt(36^N) .
* Dividing this number by 10 gives you an approximation of the number of generated IDs needed to produce a
* <1% chance of collision.
*
*
* For example, given 5 characters, the number of generated IDs need to produce a <1% chance of collision would
* be:
* sqrt(36^5)/10=777
*
* @param numchars The number of characters in the generated UUID.
* @return A new random UUID.
*/
public static String random(int numchars) {
Random r = new Random();
StringBuilder sb = new StringBuilder(numchars);
for (int i = 0; i < numchars; i++) {
int c = r.nextInt(36) + 97;
if (c > 'z')
c -= ('z'-'0'+1);
sb.append((char)c);
}
return sb.toString();
}
/**
* Same as {@link String#trim()} but prevents NullPointerExceptions .
*
* @param s The string to trim.
* @return The trimmed string, or null if the string was null .
*/
public static String trim(String s) {
if (s == null)
return null;
return s.trim();
}
/**
* Strips the first and last character from a string.
*
* @param s The string to strip.
* @return The striped string, or the same string if the input was null or less than length 2.
*/
public static String strip(String s) {
if (s == null || s.length() <= 1)
return s;
return s.substring(1, s.length()-1);
}
/**
* Parses an ISO8601 string into a date.
*
*
* Supports any of the following formats:
*
yyyy, yyyy-MM, yyyy-MM-dd, yyyy-MM-ddThh, yyyy-MM-ddThh:mm, yyyy-MM-ddThh:mm:ss, yyyy-MM-ddThh:mm:ss.SSS
*
* @param date The date string.
* @return The parsed date.
* @throws IllegalArgumentException Value was not a valid date.
*/
public static Date parseIsoDate(String date) throws IllegalArgumentException {
if (isEmpty(date))
return null;
return parseIsoCalendar(date).getTime();
}
/**
* Parses an ISO8601 string into a calendar.
*
*
* Supports any of the following formats:
*
yyyy, yyyy-MM, yyyy-MM-dd, yyyy-MM-ddThh, yyyy-MM-ddThh:mm, yyyy-MM-ddThh:mm:ss, yyyy-MM-ddThh:mm:ss.SSS
*
* @param date The date string.
* @return The parsed calendar.
* @throws IllegalArgumentException Value was not a valid date.
*/
public static Calendar parseIsoCalendar(String date) throws IllegalArgumentException {
if (isEmpty(date))
return null;
date = date.trim().replace(' ', 'T'); // Convert to 'standard' ISO8601
if (date.indexOf(',') != -1) // Trim milliseconds
date = date.substring(0, date.indexOf(','));
if (date.matches("\\d{4}"))
date += "-01-01T00:00:00";
else if (date.matches("\\d{4}\\-\\d{2}"))
date += "-01T00:00:00";
else if (date.matches("\\d{4}\\-\\d{2}\\-\\d{2}"))
date += "T00:00:00";
else if (date.matches("\\d{4}\\-\\d{2}\\-\\d{2}T\\d{2}"))
date += ":00:00";
else if (date.matches("\\d{4}\\-\\d{2}\\-\\d{2}T\\d{2}\\:\\d{2}"))
date += ":00";
return DatatypeConverter.parseDateTime(date);
}
/**
* Converts the specified object to an ISO8601 date string.
*
* @param c The object to convert.
* @return The converted object.
*/
public static String toIsoDate(Calendar c) {
return DatatypeConverter.printDate(c);
}
/**
* Converts the specified object to an ISO8601 date-time string.
*
* @param c The object to convert.
* @return The converted object.
*/
public static String toIsoDateTime(Calendar c) {
return DatatypeConverter.printDateTime(c);
}
/**
* Simple utility for replacing variables of the form "{key}" with values in the specified map.
*
*
* Nested variables are supported in both the input string and map values.
*
*
* If the map does not contain the specified value, the variable is not replaced.
*
*
* null values in the map are treated as blank strings.
*
* @param s The string containing variables to replace.
* @param m The map containing the variable values.
* @return The new string with variables replaced, or the original string if it didn't have variables in it.
*/
public static String replaceVars(String s, Map m) {
if (s == null)
return null;
if (m == null || m.isEmpty() || s.indexOf('{') == -1)
return s;
int S1 = 1; // Not in variable, looking for {
int S2 = 2; // Found {, Looking for }
int state = S1;
boolean hasInternalVar = false;
int x = 0;
int depth = 0;
int length = s.length();
StringBuilder out = new StringBuilder();
for (int i = 0; i < length; i++) {
char c = s.charAt(i);
if (state == S1) {
if (c == '{') {
state = S2;
x = i;
} else {
out.append(c);
}
} else /* state == S2 */ {
if (c == '{') {
depth++;
hasInternalVar = true;
} else if (c == '}') {
if (depth > 0) {
depth--;
} else {
String key = s.substring(x+1, i);
key = (hasInternalVar ? replaceVars(key, m) : key);
hasInternalVar = false;
if (! m.containsKey(key))
out.append('{').append(key).append('}');
else {
Object val = m.get(key);
if (val == null)
val = "";
String v = val.toString();
// If the replacement also contains variables, replace them now.
if (v.indexOf('{') != -1)
v = replaceVars(v, m);
out.append(v);
}
state = 1;
}
}
}
}
return out.toString();
}
/**
* Replaces "\\uXXXX" character sequences with their unicode characters.
*
* @param s The string to replace unicode sequences in.
* @return A string with unicode sequences replaced.
*/
public static String replaceUnicodeSequences(String s) {
if (s.indexOf('\\') == -1)
return s;
Pattern p = Pattern.compile("\\\\u(\\p{XDigit}{4})");
Matcher m = p.matcher(s);
StringBuffer sb = new StringBuffer(s.length());
while (m.find()) {
String ch = String.valueOf((char) Integer.parseInt(m.group(1), 16));
m.appendReplacement(sb, Matcher.quoteReplacement(ch));
}
m.appendTail(sb);
return sb.toString();
}
/**
* Creates an escaped-unicode sequence (e.g. "\\u1234" ) for the specified character.
*
* @param c The character to create a sequence for.
* @return An escaped-unicode sequence.
*/
public static String unicodeSequence(char c) {
StringBuilder sb = new StringBuilder(6);
sb.append('\\').append('u');
for (char cc : toHex4(c))
sb.append(cc);
return sb.toString();
}
/**
* Calls {@link #toString()} on the specified object if it's not null.
*
* @param o The object to convert to a string.
* @return The object converted to a string, or null if the object was null.
*/
public static String stringify(Object o) {
return o == null ? null : o.toString();
}
/**
* Converts the specified array to a string.
*
* @param o The array to convert to a string.
* @return The array converted to a string, or null if the object was null.
*/
public static String stringifyDeep(Object o) {
if (o == null)
return null;
if (! o.getClass().isArray())
return o.toString();
if (o.getClass().getComponentType().isPrimitive())
return PRIMITIVE_ARRAY_STRINGIFIERS.get(o.getClass()).apply(o);
return Arrays.deepToString((Object[])o);
}
private static final Map,Function