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HSQLDB example source code file (StringConverter.java)
The HSQLDB StringConverter.java source code/* * For work developed by the HSQL Development Group: * * Copyright (c) 2001-2010, The HSQL Development Group * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are met: * * Redistributions of source code must retain the above copyright notice, this * list of conditions and the following disclaimer. * * Redistributions in binary form must reproduce the above copyright notice, * this list of conditions and the following disclaimer in the documentation * and/or other materials provided with the distribution. * * Neither the name of the HSQL Development Group nor the names of its * contributors may be used to endorse or promote products derived from this * software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL HSQL DEVELOPMENT GROUP, HSQLDB.ORG, * OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. * * * * For work originally developed by the Hypersonic SQL Group: * * Copyright (c) 1995-2000, The Hypersonic SQL Group. * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are met: * * Redistributions of source code must retain the above copyright notice, this * list of conditions and the following disclaimer. * * Redistributions in binary form must reproduce the above copyright notice, * this list of conditions and the following disclaimer in the documentation * and/or other materials provided with the distribution. * * Neither the name of the Hypersonic SQL Group nor the names of its * contributors may be used to endorse or promote products derived from this * software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE HYPERSONIC SQL GROUP, * OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. * * This software consists of voluntary contributions made by many individuals * on behalf of the Hypersonic SQL Group. */ package org.hsqldb.lib; import java.io.IOException; import java.io.InputStream; import java.io.InputStreamReader; import java.io.StringWriter; import java.io.UTFDataFormatException; /** * Collection of static methods for converting strings between different * formats and to and from byte arrays.<p> * * Includes some methods based on Hypersonic code as indicated. * * @author Thomas Mueller (Hypersonic SQL Group) * @author Fred Toussi (fredt@users dot sourceforge.net) * @version 1.8.1 * @since 1.7.2 */ public class StringConverter { private static final byte[] HEXBYTES = { (byte) '0', (byte) '1', (byte) '2', (byte) '3', (byte) '4', (byte) '5', (byte) '6', (byte) '7', (byte) '8', (byte) '9', (byte) 'a', (byte) 'b', (byte) 'c', (byte) 'd', (byte) 'e', (byte) 'f' }; private static final String HEXINDEX = "0123456789abcdef0123456789ABCDEF"; /** * Converts a String into a byte array by using a big-endian two byte * representation of each char value in the string. */ byte[] stringToFullByteArray(String s) { int length = s.length(); byte[] buffer = new byte[length * 2]; int c; for (int i = 0; i < length; i++) { c = s.charAt(i); buffer[i * 2] = (byte) ((c & 0x0000ff00) >> 8); buffer[i * 2 + 1] = (byte) (c & 0x000000ff); } return buffer; } /** * Converts a hexadecimal string into a byte array * * * @param s hexadecimal string * * @return byte array for the hex string * @throws IOException */ public static byte[] hexToByte(String s) throws IOException { int l = s.length() / 2; byte[] data = new byte[l]; int j = 0; if (s.length() % 2 != 0) { throw new IOException( "hexadecimal string with odd number of characters"); } for (int i = 0; i < l; i++) { char c = s.charAt(j++); int n, b; n = HEXINDEX.indexOf(c); if (n == -1) { throw new IOException( "hexadecimal string contains non hex character"); } b = (n & 0xf) << 4; c = s.charAt(j++); n = HEXINDEX.indexOf(c); b += (n & 0xf); data[i] = (byte) b; } return data; } /** * Converts a byte array into a hexadecimal string * * * @param b byte array * * @return hex string */ public static String byteToHex(byte[] b) { int len = b.length; char[] s = new char[len * 2]; for (int i = 0, j = 0; i < len; i++) { int c = ((int) b[i]) & 0xff; s[j++] = (char) HEXBYTES[c >> 4 & 0xf]; s[j++] = (char) HEXBYTES[c & 0xf]; } return new String(s); } /** * Converts a byte array into hexadecimal characters * which are written as ASCII to the given output stream. * * @param o output stream * @param b byte array */ public static void writeHex(byte[] o, int from, byte[] b) { int len = b.length; for (int i = 0; i < len; i++) { int c = ((int) b[i]) & 0xff; o[from++] = HEXBYTES[c >> 4 & 0xf]; o[from++] = HEXBYTES[c & 0xf]; } } public static String byteToString(byte[] b, String charset) { try { return (charset == null) ? new String(b) : new String(b, charset); } catch (Exception e) {} return null; } /** * Converts a Unicode string into UTF8 then convert into a hex string * * * @param s normal Unicode string * * @return hex string representation of UTF8 encoding of the input */ public static String unicodeToHexString(String s) { HsqlByteArrayOutputStream bout = new HsqlByteArrayOutputStream(); writeUTF(s, bout); return byteToHex(bout.toByteArray()); } // fredt@users 20011120 - patch 450455 by kibu@users - modified // method return type changed to HsqlStringBuffer with spare // space for end-of-line characters -- to reduce String concatenation /** * Hsqldb specific encoding used only for log files. * * The SQL statements that need to be written to the log file (input) are * Java Unicode strings. input is converted into a 7bit escaped ASCII * string (output)with the following transformations. * All characters outside the 0x20-7f range are converted to a * escape sequence and added to output. * If a backslash character is immdediately followed by 'u', the * backslash character is converted to escape sequence and * added to output. * All the remaining characters in input are added to output without * conversion. * * The escape sequence is backslash, letter u, xxxx, where xxxx * is the hex representation of the character code. * (fredt@users) * * Method based on Hypersonic Code * * @param b output stream to wite to * @param s Java Unicode string * * @return number of bytes written out * */ public static int unicodeToAscii(HsqlByteArrayOutputStream b, String s, boolean doubleSingleQuotes) { int count = 0; if ((s == null) || (s.length() == 0)) { return 0; } int len = s.length(); for (int i = 0; i < len; i++) { char c = s.charAt(i); if (c == '\\') { if ((i < len - 1) && (s.charAt(i + 1) == 'u')) { b.write(c); // encode the \ as unicode, so 'u' is ignored b.write('u'); b.write('0'); b.write('0'); b.write('5'); b.write('c'); count += 6; } else { b.write(c); count++; } } else if ((c >= 0x0020) && (c <= 0x007f)) { b.write(c); // this is 99% count++; if (c == '\'' && doubleSingleQuotes) { b.write(c); count++; } } else { b.write('\\'); b.write('u'); b.write(HEXBYTES[(c >> 12) & 0xf]); b.write(HEXBYTES[(c >> 8) & 0xf]); b.write(HEXBYTES[(c >> 4) & 0xf]); b.write(HEXBYTES[c & 0xf]); count += 6; } } return count; } // fredt@users 20020522 - fix for 557510 - backslash bug // this legacy bug resulted from forward reading the input when a backslash // was present and manifested itself when a backslash was followed // immdediately by a character outside the 0x20-7f range in a database field. /** * Hsqldb specific decoding used only for log files. * * This method converts the 7 bit escaped ASCII strings in a log file * back into Java Unicode strings. See unicodeToAccii() above, * * @param s encoded ASCII string in byte array * @param offset position of first byte * @param length number of bytes to use * * @return Java Unicode string */ public static String asciiToUnicode(byte[] s, int offset, int length) { if (length == 0) { return ""; } char[] b = new char[length]; int j = 0; for (int i = 0; i < length; i++) { byte c = s[offset + i]; if (c == '\\' && i < length - 5) { byte c1 = s[offset + i + 1]; if (c1 == 'u') { i++; // 4 characters read should always return 0-15 int k = HEXINDEX.indexOf(s[offset + (++i)]) << 12; k += HEXINDEX.indexOf(s[offset + (++i)]) << 8; k += HEXINDEX.indexOf(s[offset + (++i)]) << 4; k += HEXINDEX.indexOf(s[offset + (++i)]); b[j++] = (char) k; } else { b[j++] = (char) c; } } else { b[j++] = (char) c; } } return new String(b, 0, j); } public static String asciiToUnicode(String s) { if ((s == null) || (s.indexOf("\\u") == -1)) { return s; } int len = s.length(); char[] b = new char[len]; int j = 0; for (int i = 0; i < len; i++) { char c = s.charAt(i); if (c == '\\' && i < len - 5) { char c1 = s.charAt(i + 1); if (c1 == 'u') { i++; // 4 characters read should always return 0-15 int k = HEXINDEX.indexOf(s.charAt(++i)) << 12; k += HEXINDEX.indexOf(s.charAt(++i)) << 8; k += HEXINDEX.indexOf(s.charAt(++i)) << 4; k += HEXINDEX.indexOf(s.charAt(++i)); b[j++] = (char) k; } else { b[j++] = c; } } else { b[j++] = c; } } return new String(b, 0, j); } public static String readUTF(byte[] bytearr, int offset, int length) throws IOException { char[] buf = new char[length]; return readUTF(bytearr, offset, length, buf); } public static String readUTF(byte[] bytearr, int offset, int length, char[] buf) throws IOException { int bcount = 0; int c, char2, char3; int count = 0; while (count < length) { c = (int) bytearr[offset + count]; if (bcount == buf.length) { buf = (char[]) ArrayUtil.resizeArray(buf, length); } if (c > 0) { /* 0xxxxxxx*/ count++; buf[bcount++] = (char) c; continue; } c &= 0xff; switch (c >> 4) { case 12 : case 13 : /* 110x xxxx 10xx xxxx*/ count += 2; if (count > length) { throw new UTFDataFormatException(); } char2 = (int) bytearr[offset + count - 1]; if ((char2 & 0xC0) != 0x80) { throw new UTFDataFormatException(); } buf[bcount++] = (char) (((c & 0x1F) << 6) | (char2 & 0x3F)); break; case 14 : /* 1110 xxxx 10xx xxxx 10xx xxxx */ count += 3; if (count > length) { throw new UTFDataFormatException(); } char2 = (int) bytearr[offset + count - 2]; char3 = (int) bytearr[offset + count - 1]; if (((char2 & 0xC0) != 0x80) || ((char3 & 0xC0) != 0x80)) { throw new UTFDataFormatException(); } buf[bcount++] = (char) (((c & 0x0F) << 12) | ((char2 & 0x3F) << 6) | ((char3 & 0x3F) << 0)); break; default : /* 10xx xxxx, 1111 xxxx */ throw new UTFDataFormatException(); } } // The number of chars produced may be less than length return new String(buf, 0, bcount); } /** * Writes a string to the specified DataOutput using UTF-8 encoding in a * machine-independent manner. * <p> * @param str a string to be written. * @param out destination to write to * @return The number of bytes written out. */ public static int writeUTF(String str, HsqlByteArrayOutputStream out) { int strlen = str.length(); int c, count = 0; if (out.count + strlen + 8 > out.buffer.length) { out.ensureRoom(strlen + 8); } for (int i = 0; i < strlen; i++) { c = str.charAt(i); if (c >= 0x0001 && c <= 0x007F) { out.write(c); count++; } else if (c > 0x07FF) { out.write(0xE0 | ((c >> 12) & 0x0F)); out.write(0x80 | ((c >> 6) & 0x3F)); out.write(0x80 | ((c >> 0) & 0x3F)); count += 3; } else { out.write(0xC0 | ((c >> 6) & 0x1F)); out.write(0x80 | ((c >> 0) & 0x3F)); count += 2; } } return count; } public static int getUTFSize(String s) { int len = (s == null) ? 0 : s.length(); int l = 0; for (int i = 0; i < len; i++) { int c = s.charAt(i); if ((c >= 0x0001) && (c <= 0x007F)) { l++; } else if (c > 0x07FF) { l += 3; } else { l += 2; } } return l; } /** * Using a Reader and a Writer, returns a String from an InputStream. */ public static String inputStreamToString(InputStream x, int length) throws IOException { InputStreamReader in = new InputStreamReader(x); StringWriter writer = new StringWriter(); int blocksize = 8 * 1024; char[] buffer = new char[blocksize]; for (int left = length; left > 0; ) { int read = in.read(buffer, 0, left > blocksize ? blocksize : left); if (read == -1) { break; } writer.write(buffer, 0, read); left -= read; } writer.close(); return writer.toString(); } // fredt@users 20020130 - patch 497872 by Nitin Chauhan - use byte[] of exact size /** * Returns the quoted version of the string using the quotechar argument. * doublequote argument indicates whether each instance of quotechar inside * the string is doubled.<p> * * null string argument returns null. If the caller needs the literal * "NULL" it should created it itself<p> * * @param s Java string * @param quoteChar character used for quoting * @param extraQuote true if quoteChar itself should be repeated * @return String */ public static String toQuotedString(String s, char quoteChar, boolean extraQuote) { if (s == null) { return null; } int count = extraQuote ? count(s, quoteChar) : 0; int len = s.length(); char[] b = new char[2 + count + len]; int i = 0; int j = 0; b[j++] = quoteChar; for (; i < len; i++) { char c = s.charAt(i); b[j++] = c; if (extraQuote && c == quoteChar) { b[j++] = c; } } b[j] = quoteChar; return new String(b); } /** * Counts Character c in String s * * @param s Java string * @param c character to count * @return int count */ static int count(final String s, final char c) { int pos = 0; int count = 0; if (s != null) { while ((pos = s.indexOf(c, pos)) > -1) { count++; pos++; } } return count; } } Other HSQLDB examples (source code examples)Here is a short list of links related to this HSQLDB StringConverter.java source code file: |
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