/
Utils.java
136 lines (120 loc) · 4.19 KB
/
Utils.java
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/*
* Copyright (C) 2007-2010 Júlio Vilmar Gesser.
* Copyright (C) 2011, 2013-2016 The JavaParser Team.
*
* This file is part of JavaParser.
*
* JavaParser can be used either under the terms of
* a) the GNU Lesser General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
* b) the terms of the Apache License
*
* You should have received a copy of both licenses in LICENCE.LGPL and
* LICENCE.APACHE. Please refer to those files for details.
*
* JavaParser is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*/
package com.github.javaparser.utils;
import java.io.IOException;
import java.io.Reader;
import java.util.*;
import java.util.stream.Collectors;
/**
* Any kind of utility.
*
* @author Federico Tomassetti
*/
public class Utils {
public static final String EOL = System.getProperty("line.separator");
public static <T> List<T> ensureNotNull(List<T> list) {
return list == null ? new ArrayList<>() : list;
}
public static <E> boolean isNullOrEmpty(Collection<E> collection) {
return collection == null || collection.isEmpty();
}
public static <T> T assertNotNull(T o) {
if (o == null) {
throw new AssertionError("A reference was unexpectedly null.");
}
return o;
}
public static String assertNonEmpty(String string) {
if (string == null || string.isEmpty()) {
throw new AssertionError("A string was unexpectedly empty.");
}
return string;
}
/**
* @return string with ASCII characters 10 and 13 replaced by the text "\n" and "\r".
*/
public static String escapeEndOfLines(String string) {
StringBuilder escapedString = new StringBuilder();
for (char c : string.toCharArray()) {
switch (c) {
case '\n':
escapedString.append("\\n");
break;
case '\r':
escapedString.append("\\r");
break;
default:
escapedString.append(c);
}
}
return escapedString.toString();
}
public static String readerToString(Reader reader) throws IOException {
final StringBuilder result = new StringBuilder();
final char[] buffer = new char[8 * 1024];
int numChars;
while ((numChars = reader.read(buffer, 0, buffer.length)) > 0) {
result.append(buffer, 0, numChars);
}
return result.toString();
}
/**
* Puts varargs in a mutable list.
* This does not have the disadvantage of Arrays#asList that it has a static size.
*/
public static <T> List<T> arrayToList(T[] array) {
List<T> list = new LinkedList<>();
Collections.addAll(list, array);
return list;
}
/**
* Transform a string to the camel case conversion.
* <p>
* For example "ABC_DEF" becomes "abcDef"
*/
public static String toCamelCase(String original) {
StringBuilder sb = new StringBuilder();
String[] parts = original.toLowerCase().split("_");
for (int i=0; i< parts.length; i++) {
sb.append(i == 0 ? parts[i] : capitalize(parts[i]));
}
return sb.toString();
}
private static String capitalize(String original) {
if (original.length() < 1) {
throw new IllegalArgumentException("This string is empty");
} else if (original.length() == 1) {
return original.toUpperCase();
} else {
return original.substring(0, 1).toUpperCase() + original.substring(1);
}
}
/**
* Return the next word of the string, in other words it stops when a space is encountered.
*/
public static String nextWord(String string) {
int index = 0;
while (index < string.length() && !Character.isWhitespace(string.charAt(index))) {
index++;
}
return string.substring(0, index);
}
}