io.netty.util.internal.StringUtil Maven / Gradle / Ivy
/*
* Copyright 2012 The Netty Project
*
* The Netty Project 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 io.netty.util.internal;
import java.util.ArrayList;
import java.util.Formatter;
import java.util.List;
/**
* String utility class.
*/
public final class StringUtil {
private StringUtil() {
// Unused.
}
public static final String NEWLINE;
static {
String newLine;
try {
newLine = new Formatter().format("%n").toString();
} catch (Exception e) {
newLine = "\n";
}
NEWLINE = newLine;
}
private static final String EMPTY_STRING = "";
/**
* Splits the specified {@link String} with the specified delimiter. This operation is a simplified and optimized
* version of {@link String#split(String)}.
*/
public static String[] split(String value, char delim) {
final int end = value.length();
final List res = new ArrayList();
int start = 0;
for (int i = 0; i < end; i ++) {
if (value.charAt(i) == delim) {
if (start == i) {
res.add(EMPTY_STRING);
} else {
res.add(value.substring(start, i));
}
start = i + 1;
}
}
if (start == 0) { // If no delimiter was found in the value
res.add(value);
} else {
if (start != end) {
// Add the last element if it's not empty.
res.add(value.substring(start, end));
} else {
// Truncate trailing empty elements.
for (int i = res.size() - 1; i >= 0; i --) {
if (res.get(i).isEmpty()) {
res.remove(i);
} else {
break;
}
}
}
}
return res.toArray(new String[res.size()]);
}
}