/*
* 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 hivemall.utils.lang;
import java.util.ArrayList;
import java.util.List;
import javax.annotation.Nonnull;
import javax.annotation.Nullable;
public final class StringUtils {
private StringUtils() {}
public static byte[] getBytes(final String s) {
final int len = s.length();
final byte[] b = new byte[len * 2];
for (int i = 0; i < len; i++) {
Primitives.putChar(b, i * 2, s.charAt(i));
}
return b;
}
public static String toString(byte[] b) {
return toString(b, 0, b.length);
}
public static String toString(byte[] b, int off, int len) {
final int clen = len >>> 1;
final char[] c = new char[clen];
for (int i = 0; i < clen; i++) {
final int j = off + (i << 1);
c[i] = (char) ((b[j + 1] & 0xFF) + ((b[j + 0]) << 8));
}
return new String(c);
}
/**
* Checks whether the String a valid Java number. this code is ported from jakarta commons lang.
*
* @link http://jakarta.apache.org/commons/lang/apidocs/org/apache/commons/lang
* /math/NumberUtils.html
*/
public static boolean isNumber(final String str) {
if (str == null || str.length() == 0) {
return false;
}
char[] chars = str.toCharArray();
int sz = chars.length;
boolean hasExp = false;
boolean hasDecPoint = false;
boolean allowSigns = false;
boolean foundDigit = false;
// deal with any possible sign up front
int start = (chars[0] == '-') ? 1 : 0;
if (sz > start + 1) {
if (chars[start] == '0' && chars[start + 1] == 'x') {
int i = start + 2;
if (i == sz) {
return false; // str == "0x"
}
// checking hex (it can't be anything else)
for (; i < chars.length; i++) {
if ((chars[i] < '0' || chars[i] > '9') && (chars[i] < 'a' || chars[i] > 'f')
&& (chars[i] < 'A' || chars[i] > 'F')) {
return false;
}
}
return true;
}
}
sz--; // don't want to loop to the last char, check it afterwords
// for type qualifiers
int i = start;
// loop to the next to last char or to the last char if we need another digit to
// make a valid number (e.g. chars[0..5] = "1234E")
while (i < sz || (i < sz + 1 && allowSigns && !foundDigit)) {
if (chars[i] >= '0' && chars[i] <= '9') {
foundDigit = true;
allowSigns = false;
} else if (chars[i] == '.') {
if (hasDecPoint || hasExp) {
// two decimal points or dec in exponent
return false;
}
hasDecPoint = true;
} else if (chars[i] == 'e' || chars[i] == 'E') {
// we've already taken care of hex.
if (hasExp) {
// two E's
return false;
}
if (!foundDigit) {
return false;
}
hasExp = true;
allowSigns = true;
} else if (chars[i] == '+' || chars[i] == '-') {
if (!allowSigns) {
return false;
}
allowSigns = false;
foundDigit = false; // we need a digit after the E
} else {
return false;
}
i++;
}
if (i < chars.length) {
if (chars[i] >= '0' && chars[i] <= '9') {
// no type qualifier, OK
return true;
}
if (chars[i] == 'e' || chars[i] == 'E') {
// can't have an E at the last byte
return false;
}
if (!allowSigns
&& (chars[i] == 'd' || chars[i] == 'D' || chars[i] == 'f' || chars[i] == 'F')) {
return foundDigit;
}
if (chars[i] == 'l' || chars[i] == 'L') {
// not allowing L with an exponent
return foundDigit && !hasExp;
}
// last character is illegal
return false;
}
// allowSigns is true iff the val ends in 'E'
// found digit it to make sure weird stuff like '.' and '1E-' doesn't pass
return !allowSigns && foundDigit;
}
public static boolean isInt(@Nonnull final String i) {
try {
Integer.parseInt(i);
return true;
} catch (NumberFormatException nfe) {
return false;
}
}
public static boolean isDouble(@Nonnull final String i) {
try {
Double.parseDouble(i);
return true;
} catch (NumberFormatException nfe) {
return false;
}
}
public static void clear(@Nonnull final StringBuilder buf) {
buf.setLength(0);
}
public static String concat(@Nonnull final List<String> list, @Nonnull final String sep) {
final StringBuilder buf = new StringBuilder(128);
for (String s : list) {
if (s == null) {
continue;
}
buf.append(s);
buf.append(sep);
}
return buf.toString();
}
public static String[] split(final String str, final char separatorChar) {
return split(str, separatorChar, false);
}
public static String[] split(final String str, final char separatorChar,
final boolean preserveAllTokens) {
if (str == null) {
return null;
}
final int len = str.length();
if (len == 0) {
return new String[0];
}
final List<String> list = new ArrayList<String>();
int i = 0, start = 0;
boolean match = false;
boolean lastMatch = false;
while (i < len) {
if (str.charAt(i) == separatorChar) {
if (match || preserveAllTokens) {
list.add(str.substring(start, i));
match = false;
lastMatch = true;
}
start = ++i;
continue;
}
lastMatch = false;
match = true;
i++;
}
if (match || preserveAllTokens && lastMatch) {
list.add(str.substring(start, i));
}
return list.toArray(new String[list.size()]);
}
@Nonnull
public static String format(@Nullable String template, @Nullable Object... args) {
template = String.valueOf(template);
StringBuilder builder = new StringBuilder(template.length() + 16 * args.length);
int templateStart = 0;
int i = 0;
while (i < args.length) {
int placeholderStart = template.indexOf("%s", templateStart);
if (placeholderStart == -1) {
break;
}
builder.append(template, templateStart, placeholderStart);
builder.append(args[i++]);
templateStart = placeholderStart + 2;
}
builder.append(template, templateStart, template.length());
if (i < args.length) {
builder.append(" [");
builder.append(args[i++]);
while (i < args.length) {
builder.append(", ");
builder.append(args[i++]);
}
builder.append(']');
}
return builder.toString();
}
}