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The Convert.java Java example source code
/*
* Copyright (c) 1999, 2013, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code 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 General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
package com.sun.tools.javac.util;
/** Utility class for static conversion methods between numbers
* and strings in various formats.
*
* <p>Note regarding UTF-8.
* The JVMS defines its own version of the UTF-8 format so that it
* contains no zero bytes (modified UTF-8). This is not actually the same
* as Charset.forName("UTF-8").
*
* <p>
* See also:
* <ul>
* <li>
* JVMS 4.4.7 </a>
* <li>
java.io.DataInput: Modified UTF-8 </a>
<li>
Modified UTF-8 (wikipedia) </a>
* </ul>
*
* The methods here support modified UTF-8.
*
* <p>This is NOT part of any supported API.
* If you write code that depends on this, you do so at your own risk.
* This code and its internal interfaces are subject to change or
* deletion without notice.</b>
*/
public class Convert {
/** Convert string to integer.
*/
public static int string2int(String s, int radix)
throws NumberFormatException {
if (radix == 10) {
return Integer.parseInt(s, radix);
} else {
char[] cs = s.toCharArray();
int limit = Integer.MAX_VALUE / (radix/2);
int n = 0;
for (int i = 0; i < cs.length; i++) {
int d = Character.digit(cs[i], radix);
if (n < 0 ||
n > limit ||
n * radix > Integer.MAX_VALUE - d)
throw new NumberFormatException();
n = n * radix + d;
}
return n;
}
}
/** Convert string to long integer.
*/
public static long string2long(String s, int radix)
throws NumberFormatException {
if (radix == 10) {
return Long.parseLong(s, radix);
} else {
char[] cs = s.toCharArray();
long limit = Long.MAX_VALUE / (radix/2);
long n = 0;
for (int i = 0; i < cs.length; i++) {
int d = Character.digit(cs[i], radix);
if (n < 0 ||
n > limit ||
n * radix > Long.MAX_VALUE - d)
throw new NumberFormatException();
n = n * radix + d;
}
return n;
}
}
/* Conversion routines between names, strings, and byte arrays in Utf8 format
*/
/** Convert `len' bytes from utf8 to characters.
* Parameters are as in System.arraycopy
* Return first index in `dst' past the last copied char.
* @param src The array holding the bytes to convert.
* @param sindex The start index from which bytes are converted.
* @param dst The array holding the converted characters..
* @param dindex The start index from which converted characters
* are written.
* @param len The maximum number of bytes to convert.
*/
public static int utf2chars(byte[] src, int sindex,
char[] dst, int dindex,
int len) {
int i = sindex;
int j = dindex;
int limit = sindex + len;
while (i < limit) {
int b = src[i++] & 0xFF;
if (b >= 0xE0) {
b = (b & 0x0F) << 12;
b = b | (src[i++] & 0x3F) << 6;
b = b | (src[i++] & 0x3F);
} else if (b >= 0xC0) {
b = (b & 0x1F) << 6;
b = b | (src[i++] & 0x3F);
}
dst[j++] = (char)b;
}
return j;
}
/** Return bytes in Utf8 representation as an array of characters.
* @param src The array holding the bytes.
* @param sindex The start index from which bytes are converted.
* @param len The maximum number of bytes to convert.
*/
public static char[] utf2chars(byte[] src, int sindex, int len) {
char[] dst = new char[len];
int len1 = utf2chars(src, sindex, dst, 0, len);
char[] result = new char[len1];
System.arraycopy(dst, 0, result, 0, len1);
return result;
}
/** Return all bytes of a given array in Utf8 representation
* as an array of characters.
* @param src The array holding the bytes.
*/
public static char[] utf2chars(byte[] src) {
return utf2chars(src, 0, src.length);
}
/** Return bytes in Utf8 representation as a string.
* @param src The array holding the bytes.
* @param sindex The start index from which bytes are converted.
* @param len The maximum number of bytes to convert.
*/
public static String utf2string(byte[] src, int sindex, int len) {
char dst[] = new char[len];
int len1 = utf2chars(src, sindex, dst, 0, len);
return new String(dst, 0, len1);
}
/** Return all bytes of a given array in Utf8 representation
* as a string.
* @param src The array holding the bytes.
*/
public static String utf2string(byte[] src) {
return utf2string(src, 0, src.length);
}
/** Copy characters in source array to bytes in target array,
* converting them to Utf8 representation.
* The target array must be large enough to hold the result.
* returns first index in `dst' past the last copied byte.
* @param src The array holding the characters to convert.
* @param sindex The start index from which characters are converted.
* @param dst The array holding the converted characters..
* @param dindex The start index from which converted bytes
* are written.
* @param len The maximum number of characters to convert.
*/
public static int chars2utf(char[] src, int sindex,
byte[] dst, int dindex,
int len) {
int j = dindex;
int limit = sindex + len;
for (int i = sindex; i < limit; i++) {
char ch = src[i];
if (1 <= ch && ch <= 0x7F) {
dst[j++] = (byte)ch;
} else if (ch <= 0x7FF) {
dst[j++] = (byte)(0xC0 | (ch >> 6));
dst[j++] = (byte)(0x80 | (ch & 0x3F));
} else {
dst[j++] = (byte)(0xE0 | (ch >> 12));
dst[j++] = (byte)(0x80 | ((ch >> 6) & 0x3F));
dst[j++] = (byte)(0x80 | (ch & 0x3F));
}
}
return j;
}
/** Return characters as an array of bytes in Utf8 representation.
* @param src The array holding the characters.
* @param sindex The start index from which characters are converted.
* @param len The maximum number of characters to convert.
*/
public static byte[] chars2utf(char[] src, int sindex, int len) {
byte[] dst = new byte[len * 3];
int len1 = chars2utf(src, sindex, dst, 0, len);
byte[] result = new byte[len1];
System.arraycopy(dst, 0, result, 0, len1);
return result;
}
/** Return all characters in given array as an array of bytes
* in Utf8 representation.
* @param src The array holding the characters.
*/
public static byte[] chars2utf(char[] src) {
return chars2utf(src, 0, src.length);
}
/** Return string as an array of bytes in in Utf8 representation.
*/
public static byte[] string2utf(String s) {
return chars2utf(s.toCharArray());
}
/**
* Escapes each character in a string that has an escape sequence or
* is non-printable ASCII. Leaves non-ASCII characters alone.
*/
public static String quote(String s) {
StringBuilder buf = new StringBuilder();
for (int i = 0; i < s.length(); i++) {
buf.append(quote(s.charAt(i)));
}
return buf.toString();
}
/**
* Escapes a character if it has an escape sequence or is
* non-printable ASCII. Leaves non-ASCII characters alone.
*/
public static String quote(char ch) {
switch (ch) {
case '\b': return "\\b";
case '\f': return "\\f";
case '\n': return "\\n";
case '\r': return "\\r";
case '\t': return "\\t";
case '\'': return "\\'";
case '\"': return "\\\"";
case '\\': return "\\\\";
default:
return (isPrintableAscii(ch))
? String.valueOf(ch)
: String.format("\\u%04x", (int) ch);
}
}
/**
* Is a character printable ASCII?
*/
private static boolean isPrintableAscii(char ch) {
return ch >= ' ' && ch <= '~';
}
/** Escape all unicode characters in string.
*/
public static String escapeUnicode(String s) {
int len = s.length();
int i = 0;
while (i < len) {
char ch = s.charAt(i);
if (ch > 255) {
StringBuilder buf = new StringBuilder();
buf.append(s.substring(0, i));
while (i < len) {
ch = s.charAt(i);
if (ch > 255) {
buf.append("\\u");
buf.append(Character.forDigit((ch >> 12) % 16, 16));
buf.append(Character.forDigit((ch >> 8) % 16, 16));
buf.append(Character.forDigit((ch >> 4) % 16, 16));
buf.append(Character.forDigit((ch ) % 16, 16));
} else {
buf.append(ch);
}
i++;
}
s = buf.toString();
} else {
i++;
}
}
return s;
}
/* Conversion routines for qualified name splitting
*/
/** Return the last part of a class name.
*/
public static Name shortName(Name classname) {
return classname.subName(
classname.lastIndexOf((byte)'.') + 1, classname.getByteLength());
}
public static String shortName(String classname) {
return classname.substring(classname.lastIndexOf('.') + 1);
}
/** Return the package name of a class name, excluding the trailing '.',
* "" if not existent.
*/
public static Name packagePart(Name classname) {
return classname.subName(0, classname.lastIndexOf((byte)'.'));
}
public static String packagePart(String classname) {
int lastDot = classname.lastIndexOf('.');
return (lastDot < 0 ? "" : classname.substring(0, lastDot));
}
public static List<Name> enclosingCandidates(Name name) {
List<Name> names = List.nil();
int index;
while ((index = name.lastIndexOf((byte)'$')) > 0) {
name = name.subName(0, index);
names = names.prepend(name);
}
return names;
}
}
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