io.netty.util.internal.StringUtil Maven / Gradle / Ivy
Go to download
This artifact provides a single jar that contains all classes required to use remote EJB and JMS, including
all dependencies. It is intended for use by those not using maven, maven users should just import the EJB and
JMS BOM's instead (shaded JAR's cause lots of problems with maven, as it is very easy to inadvertently end up
with different versions on classes on the class path).
/*
* 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.io.IOException;
import java.util.ArrayList;
import java.util.Formatter;
import java.util.List;
/**
* String utility class.
*/
public final class StringUtil {
public static final String NEWLINE;
private static final String[] BYTE2HEX_PAD = new String[256];
private static final String[] BYTE2HEX_NOPAD = new String[256];
private static final String EMPTY_STRING = "";
static {
// Determine the newline character of the current platform.
String newLine;
try {
newLine = new Formatter().format("%n").toString();
} catch (Exception e) {
// Should not reach here, but just in case.
newLine = "\n";
}
NEWLINE = newLine;
// Generate the lookup table that converts a byte into a 2-digit hexadecimal integer.
int i;
for (i = 0; i < 10; i ++) {
StringBuilder buf = new StringBuilder(2);
buf.append('0');
buf.append(i);
BYTE2HEX_PAD[i] = buf.toString();
BYTE2HEX_NOPAD[i] = String.valueOf(i);
}
for (; i < 16; i ++) {
StringBuilder buf = new StringBuilder(2);
char c = (char) ('a' + i - 10);
buf.append('0');
buf.append(c);
BYTE2HEX_PAD[i] = buf.toString();
BYTE2HEX_NOPAD[i] = String.valueOf(c);
}
for (; i < BYTE2HEX_PAD.length; i ++) {
StringBuilder buf = new StringBuilder(2);
buf.append(Integer.toHexString(i));
String str = buf.toString();
BYTE2HEX_PAD[i] = str;
BYTE2HEX_NOPAD[i] = str;
}
}
/**
* 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()]);
}
/**
* Splits the specified {@link String} with the specified delimiter in maxParts maximum parts.
* This operation is a simplified and optimized
* version of {@link String#split(String, int)}.
*/
public static String[] split(String value, char delim, int maxParts) {
final int end = value.length();
final List res = new ArrayList();
int start = 0;
int cpt = 1;
for (int i = 0; i < end && cpt < maxParts; i ++) {
if (value.charAt(i) == delim) {
if (start == i) {
res.add(EMPTY_STRING);
} else {
res.add(value.substring(start, i));
}
start = i + 1;
cpt++;
}
}
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()]);
}
/**
* Get the item after one char delim if the delim is found (else null).
* This operation is a simplified and optimized
* version of {@link String#split(String, int)}.
*/
public static String substringAfter(String value, char delim) {
int pos = value.indexOf(delim);
if (pos >= 0) {
return value.substring(pos + 1);
}
return null;
}
/**
* Converts the specified byte value into a 2-digit hexadecimal integer.
*/
public static String byteToHexStringPadded(int value) {
return BYTE2HEX_PAD[value & 0xff];
}
/**
* Converts the specified byte value into a 2-digit hexadecimal integer and appends it to the specified buffer.
*/
public static T byteToHexStringPadded(T buf, int value) {
try {
buf.append(byteToHexStringPadded(value));
} catch (IOException e) {
PlatformDependent.throwException(e);
}
return buf;
}
/**
* Converts the specified byte array into a hexadecimal value.
*/
public static String toHexStringPadded(byte[] src) {
return toHexStringPadded(src, 0, src.length);
}
/**
* Converts the specified byte array into a hexadecimal value.
*/
public static String toHexStringPadded(byte[] src, int offset, int length) {
return toHexStringPadded(new StringBuilder(length << 1), src, offset, length).toString();
}
/**
* Converts the specified byte array into a hexadecimal value and appends it to the specified buffer.
*/
public static T toHexStringPadded(T dst, byte[] src) {
return toHexStringPadded(dst, src, 0, src.length);
}
/**
* Converts the specified byte array into a hexadecimal value and appends it to the specified buffer.
*/
public static T toHexStringPadded(T dst, byte[] src, int offset, int length) {
final int end = offset + length;
for (int i = offset; i < end; i ++) {
byteToHexStringPadded(dst, src[i]);
}
return dst;
}
/**
* Converts the specified byte value into a hexadecimal integer.
*/
public static String byteToHexString(int value) {
return BYTE2HEX_NOPAD[value & 0xff];
}
/**
* Converts the specified byte value into a hexadecimal integer and appends it to the specified buffer.
*/
public static T byteToHexString(T buf, int value) {
try {
buf.append(byteToHexString(value));
} catch (IOException e) {
PlatformDependent.throwException(e);
}
return buf;
}
/**
* Converts the specified byte array into a hexadecimal value.
*/
public static String toHexString(byte[] src) {
return toHexString(src, 0, src.length);
}
/**
* Converts the specified byte array into a hexadecimal value.
*/
public static String toHexString(byte[] src, int offset, int length) {
return toHexString(new StringBuilder(length << 1), src, offset, length).toString();
}
/**
* Converts the specified byte array into a hexadecimal value and appends it to the specified buffer.
*/
public static T toHexString(T dst, byte[] src) {
return toHexString(dst, src, 0, src.length);
}
/**
* Converts the specified byte array into a hexadecimal value and appends it to the specified buffer.
*/
public static T toHexString(T dst, byte[] src, int offset, int length) {
assert length >= 0;
if (length == 0) {
return dst;
}
final int end = offset + length;
final int endMinusOne = end - 1;
int i;
// Skip preceding zeroes.
for (i = offset; i < endMinusOne; i ++) {
if (src[i] != 0) {
break;
}
}
byteToHexString(dst, src[i ++]);
int remaining = end - i;
toHexStringPadded(dst, src, i, remaining);
return dst;
}
/**
* The shortcut to {@link #simpleClassName(Class) simpleClassName(o.getClass())}.
*/
public static String simpleClassName(Object o) {
if (o == null) {
return "null_object";
} else {
return simpleClassName(o.getClass());
}
}
/**
* Generates a simplified name from a {@link Class}. Similar to {@link Class#getSimpleName()}, but it works fine
* with anonymous classes.
*/
public static String simpleClassName(Class clazz) {
if (clazz == null) {
return "null_class";
}
Package pkg = clazz.getPackage();
if (pkg != null) {
return clazz.getName().substring(pkg.getName().length() + 1);
} else {
return clazz.getName();
}
}
private StringUtil() {
// Unused.
}
}