StringUtils.java
- /*
- * Copyright (C) 2009-2022, Google Inc. and others
- *
- * This program and the accompanying materials are made available under the
- * terms of the Eclipse Distribution License v. 1.0 which is available at
- * https://www.eclipse.org/org/documents/edl-v10.php.
- *
- * SPDX-License-Identifier: BSD-3-Clause
- */
- package org.eclipse.jgit.util;
- import java.text.MessageFormat;
- import java.util.Collection;
- import org.eclipse.jgit.annotations.NonNull;
- import org.eclipse.jgit.internal.JGitText;
- import org.eclipse.jgit.lib.Constants;
- /**
- * Miscellaneous string comparison utility methods.
- */
- public final class StringUtils {
- private static final long KiB = 1024;
- private static final long MiB = 1024 * KiB;
- private static final long GiB = 1024 * MiB;
- private static final char[] LC;
- static {
- LC = new char['Z' + 1];
- for (char c = 0; c < LC.length; c++)
- LC[c] = c;
- for (char c = 'A'; c <= 'Z'; c++)
- LC[c] = (char) ('a' + (c - 'A'));
- }
- private StringUtils() {
- // Do not create instances
- }
- /**
- * Convert the input to lowercase.
- * <p>
- * This method does not honor the JVM locale, but instead always behaves as
- * though it is in the US-ASCII locale. Only characters in the range 'A'
- * through 'Z' are converted. All other characters are left as-is, even if
- * they otherwise would have a lowercase character equivalent.
- *
- * @param c
- * the input character.
- * @return lowercase version of the input.
- */
- public static char toLowerCase(char c) {
- return c <= 'Z' ? LC[c] : c;
- }
- /**
- * Convert the input string to lower case, according to the "C" locale.
- * <p>
- * This method does not honor the JVM locale, but instead always behaves as
- * though it is in the US-ASCII locale. Only characters in the range 'A'
- * through 'Z' are converted, all other characters are left as-is, even if
- * they otherwise would have a lowercase character equivalent.
- *
- * @param in
- * the input string. Must not be null.
- * @return a copy of the input string, after converting characters in the
- * range 'A'..'Z' to 'a'..'z'.
- */
- public static String toLowerCase(String in) {
- final StringBuilder r = new StringBuilder(in.length());
- for (int i = 0; i < in.length(); i++)
- r.append(toLowerCase(in.charAt(i)));
- return r.toString();
- }
- /**
- * Borrowed from commons-lang <code>StringUtils.capitalize()</code> method.
- *
- * <p>
- * Capitalizes a String changing the first letter to title case as per
- * {@link java.lang.Character#toTitleCase(char)}. No other letters are
- * changed.
- * </p>
- * <p>
- * A <code>null</code> input String returns <code>null</code>.
- * </p>
- *
- * @param str
- * the String to capitalize, may be null
- * @return the capitalized String, <code>null</code> if null String input
- * @since 4.0
- */
- public static String capitalize(String str) {
- int strLen;
- if (str == null || (strLen = str.length()) == 0) {
- return str;
- }
- return new StringBuilder(strLen)
- .append(Character.toTitleCase(str.charAt(0)))
- .append(str.substring(1)).toString();
- }
- /**
- * Test if two strings are equal, ignoring case.
- * <p>
- * This method does not honor the JVM locale, but instead always behaves as
- * though it is in the US-ASCII locale.
- *
- * @param a
- * first string to compare.
- * @param b
- * second string to compare.
- * @return true if a equals b
- */
- public static boolean equalsIgnoreCase(String a, String b) {
- if (References.isSameObject(a, b)) {
- return true;
- }
- if (a.length() != b.length())
- return false;
- for (int i = 0; i < a.length(); i++) {
- if (toLowerCase(a.charAt(i)) != toLowerCase(b.charAt(i)))
- return false;
- }
- return true;
- }
- /**
- * Compare two strings, ignoring case.
- * <p>
- * This method does not honor the JVM locale, but instead always behaves as
- * though it is in the US-ASCII locale.
- *
- * @param a
- * first string to compare.
- * @param b
- * second string to compare.
- * @since 2.0
- * @return an int.
- */
- public static int compareIgnoreCase(String a, String b) {
- for (int i = 0; i < a.length() && i < b.length(); i++) {
- int d = toLowerCase(a.charAt(i)) - toLowerCase(b.charAt(i));
- if (d != 0)
- return d;
- }
- return a.length() - b.length();
- }
- /**
- * Compare two strings, honoring case.
- * <p>
- * This method does not honor the JVM locale, but instead always behaves as
- * though it is in the US-ASCII locale.
- *
- * @param a
- * first string to compare.
- * @param b
- * second string to compare.
- * @since 2.0
- * @return an int.
- */
- public static int compareWithCase(String a, String b) {
- for (int i = 0; i < a.length() && i < b.length(); i++) {
- int d = a.charAt(i) - b.charAt(i);
- if (d != 0)
- return d;
- }
- return a.length() - b.length();
- }
- /**
- * Parse a string as a standard Git boolean value. See
- * {@link #toBooleanOrNull(String)}.
- *
- * @param stringValue
- * the string to parse.
- * @return the boolean interpretation of {@code value}.
- * @throws java.lang.IllegalArgumentException
- * if {@code value} is not recognized as one of the standard
- * boolean names.
- */
- public static boolean toBoolean(String stringValue) {
- if (stringValue == null)
- throw new NullPointerException(JGitText.get().expectedBooleanStringValue);
- final Boolean bool = toBooleanOrNull(stringValue);
- if (bool == null)
- throw new IllegalArgumentException(MessageFormat.format(JGitText.get().notABoolean, stringValue));
- return bool.booleanValue();
- }
- /**
- * Parse a string as a standard Git boolean value.
- * <p>
- * The terms {@code yes}, {@code true}, {@code 1}, {@code on} can all be
- * used to mean {@code true}.
- * <p>
- * The terms {@code no}, {@code false}, {@code 0}, {@code off} can all be
- * used to mean {@code false}.
- * <p>
- * Comparisons ignore case, via {@link #equalsIgnoreCase(String, String)}.
- *
- * @param stringValue
- * the string to parse.
- * @return the boolean interpretation of {@code value} or null in case the
- * string does not represent a boolean value
- */
- public static Boolean toBooleanOrNull(String stringValue) {
- if (stringValue == null)
- return null;
- if (equalsIgnoreCase("yes", stringValue) //$NON-NLS-1$
- || equalsIgnoreCase("true", stringValue) //$NON-NLS-1$
- || equalsIgnoreCase("1", stringValue) //$NON-NLS-1$
- || equalsIgnoreCase("on", stringValue)) //$NON-NLS-1$
- return Boolean.TRUE;
- else if (equalsIgnoreCase("no", stringValue) //$NON-NLS-1$
- || equalsIgnoreCase("false", stringValue) //$NON-NLS-1$
- || equalsIgnoreCase("0", stringValue) //$NON-NLS-1$
- || equalsIgnoreCase("off", stringValue)) //$NON-NLS-1$
- return Boolean.FALSE;
- else
- return null;
- }
- /**
- * Join a collection of Strings together using the specified separator.
- *
- * @param parts
- * Strings to join
- * @param separator
- * used to join
- * @return a String with all the joined parts
- */
- public static String join(Collection<String> parts, String separator) {
- return StringUtils.join(parts, separator, separator);
- }
- /**
- * Join a collection of Strings together using the specified separator and a
- * lastSeparator which is used for joining the second last and the last
- * part.
- *
- * @param parts
- * Strings to join
- * @param separator
- * separator used to join all but the two last elements
- * @param lastSeparator
- * separator to use for joining the last two elements
- * @return a String with all the joined parts
- */
- public static String join(Collection<String> parts, String separator,
- String lastSeparator) {
- StringBuilder sb = new StringBuilder();
- int i = 0;
- int lastIndex = parts.size() - 1;
- for (String part : parts) {
- sb.append(part);
- if (i == lastIndex - 1) {
- sb.append(lastSeparator);
- } else if (i != lastIndex) {
- sb.append(separator);
- }
- i++;
- }
- return sb.toString();
- }
- /**
- * Appends {@link Constants#DOT_GIT_EXT} unless the given name already ends
- * with that suffix.
- *
- * @param name
- * to complete
- * @return the name ending with {@link Constants#DOT_GIT_EXT}
- * @since 6.1
- */
- public static String nameWithDotGit(String name) {
- if (name.endsWith(Constants.DOT_GIT_EXT)) {
- return name;
- }
- return name + Constants.DOT_GIT_EXT;
- }
- /**
- * Test if a string is empty or null.
- *
- * @param stringValue
- * the string to check
- * @return <code>true</code> if the string is <code>null</code> or empty
- */
- public static boolean isEmptyOrNull(String stringValue) {
- return stringValue == null || stringValue.length() == 0;
- }
- /**
- * Replace CRLF, CR or LF with a single space.
- *
- * @param in
- * A string with line breaks
- * @return in without line breaks
- * @since 3.1
- */
- public static String replaceLineBreaksWithSpace(String in) {
- char[] buf = new char[in.length()];
- int o = 0;
- for (int i = 0; i < buf.length; ++i) {
- char ch = in.charAt(i);
- switch (ch) {
- case '\r':
- if (i + 1 < buf.length && in.charAt(i + 1) == '\n') {
- buf[o++] = ' ';
- ++i;
- } else
- buf[o++] = ' ';
- break;
- case '\n':
- buf[o++] = ' ';
- break;
- default:
- buf[o++] = ch;
- break;
- }
- }
- return new String(buf, 0, o);
- }
- /**
- * Parses a number with optional case-insensitive suffix 'k', 'm', or 'g'
- * indicating KiB, MiB, and GiB, respectively. The suffix may follow the
- * number with optional separation by one or more blanks.
- *
- * @param value
- * {@link String} to parse; with leading and trailing whitespace
- * ignored
- * @param positiveOnly
- * {@code true} to only accept positive numbers, {@code false} to
- * allow negative numbers, too
- * @return the value parsed
- * @throws NumberFormatException
- * if the {@value} is not parseable, or beyond the range of
- * {@link Long}
- * @throws StringIndexOutOfBoundsException
- * if the string is empty or contains only whitespace, or
- * contains only the letter 'k', 'm', or 'g'
- * @since 6.0
- */
- public static long parseLongWithSuffix(@NonNull String value,
- boolean positiveOnly)
- throws NumberFormatException, StringIndexOutOfBoundsException {
- String n = value.strip();
- if (n.isEmpty()) {
- throw new StringIndexOutOfBoundsException();
- }
- long mul = 1;
- switch (n.charAt(n.length() - 1)) {
- case 'g':
- case 'G':
- mul = GiB;
- break;
- case 'm':
- case 'M':
- mul = MiB;
- break;
- case 'k':
- case 'K':
- mul = KiB;
- break;
- default:
- break;
- }
- if (mul > 1) {
- n = n.substring(0, n.length() - 1).trim();
- }
- if (n.isEmpty()) {
- throw new StringIndexOutOfBoundsException();
- }
- long number;
- if (positiveOnly) {
- number = Long.parseUnsignedLong(n);
- if (number < 0) {
- throw new NumberFormatException(
- MessageFormat.format(JGitText.get().valueExceedsRange,
- value, Long.class.getSimpleName()));
- }
- } else {
- number = Long.parseLong(n);
- }
- if (mul == 1) {
- return number;
- }
- try {
- return Math.multiplyExact(mul, number);
- } catch (ArithmeticException e) {
- NumberFormatException nfe = new NumberFormatException(
- e.getLocalizedMessage());
- nfe.initCause(e);
- throw nfe;
- }
- }
- /**
- * Parses a number with optional case-insensitive suffix 'k', 'm', or 'g'
- * indicating KiB, MiB, and GiB, respectively. The suffix may follow the
- * number with optional separation by blanks.
- *
- * @param value
- * {@link String} to parse; with leading and trailing whitespace
- * ignored
- * @param positiveOnly
- * {@code true} to only accept positive numbers, {@code false} to
- * allow negative numbers, too
- * @return the value parsed
- * @throws NumberFormatException
- * if the {@value} is not parseable or beyond the range of
- * {@link Integer}
- * @throws StringIndexOutOfBoundsException
- * if the string is empty or contains only whitespace, or
- * contains only the letter 'k', 'm', or 'g'
- * @since 6.0
- */
- public static int parseIntWithSuffix(@NonNull String value,
- boolean positiveOnly)
- throws NumberFormatException, StringIndexOutOfBoundsException {
- try {
- return Math.toIntExact(parseLongWithSuffix(value, positiveOnly));
- } catch (ArithmeticException e) {
- NumberFormatException nfe = new NumberFormatException(
- MessageFormat.format(JGitText.get().valueExceedsRange,
- value, Integer.class.getSimpleName()));
- nfe.initCause(e);
- throw nfe;
- }
- }
- /**
- * Formats an integral value as a decimal number with 'k', 'm', or 'g'
- * suffix if it is an exact multiple of 1024, otherwise returns the value
- * representation as a decimal number without suffix.
- *
- * @param value
- * Value to format
- * @return the value's String representation
- * @since 6.0
- */
- public static String formatWithSuffix(long value) {
- if (value >= GiB && (value % GiB) == 0) {
- return String.valueOf(value / GiB) + 'g';
- }
- if (value >= MiB && (value % MiB) == 0) {
- return String.valueOf(value / MiB) + 'm';
- }
- if (value >= KiB && (value % KiB) == 0) {
- return String.valueOf(value / KiB) + 'k';
- }
- return String.valueOf(value);
- }
- }