Java tutorial
/** * * JFreeReport : a free Java reporting library * * * Project Info: http://reporting.pentaho.org/ * * (C) Copyright 2001-2007, by Object Refinery Ltd, Pentaho Corporation and Contributors. * * This library is free software; you can redistribute it and/or modify it under the terms * of the GNU Lesser General Public License as published by the Free Software Foundation; * either version 2.1 of the License, or (at your option) any later version. * * This library 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 Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public License along with this * library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, * Boston, MA 02111-1307, USA. * * [Java is a trademark or registered trademark of Sun Microsystems, Inc. * in the United States and other countries.] * * ------------ * UTFEncodingUtil.java * ------------ * (C) Copyright 2001-2007, by Object Refinery Ltd, Pentaho Corporation and Contributors. */ import java.io.UnsupportedEncodingException; /** * Provides a method to encode any string into a URL-safe form. Non-ASCII characters are first encoded as sequences of * two or three bytes, using the UTF-8 algorithm, before being encoded as %HH escapes. * <p/> * Code is the public example given at http://www.w3.org/International/O-URL-code.html * * @author Bert Bos */ public class UTFEncodingUtil { /** * Private Constructor prevents Object Creation. */ private UTFEncodingUtil() { } /** * A lookup table. */ private static final String[] hex = { "%00", "%01", "%02", "%03", "%04", "%05", "%06", "%07", "%08", "%09", "%0A", "%0B", "%0C", "%0D", "%0E", "%0F", "%10", "%11", "%12", "%13", "%14", "%15", "%16", "%17", "%18", "%19", "%1A", "%1B", "%1C", "%1D", "%1E", "%1F", "%20", "%21", "%22", "%23", "%24", "%25", "%26", "%27", "%28", "%29", "%2A", "%2B", "%2C", "%2D", "%2E", "%2F", "%30", "%31", "%32", "%33", "%34", "%35", "%36", "%37", "%38", "%39", "%3A", "%3B", "%3C", "%3D", "%3E", "%3F", "%40", "%41", "%42", "%43", "%44", "%45", "%46", "%47", "%48", "%49", "%4A", "%4B", "%4C", "%4D", "%4E", "%4F", "%50", "%51", "%52", "%53", "%54", "%55", "%56", "%57", "%58", "%59", "%5A", "%5B", "%5C", "%5D", "%5E", "%5F", "%60", "%61", "%62", "%63", "%64", "%65", "%66", "%67", "%68", "%69", "%6A", "%6B", "%6C", "%6D", "%6E", "%6F", "%70", "%71", "%72", "%73", "%74", "%75", "%76", "%77", "%78", "%79", "%7A", "%7B", "%7C", "%7D", "%7E", "%7F", "%80", "%81", "%82", "%83", "%84", "%85", "%86", "%87", "%88", "%89", "%8A", "%8B", "%8C", "%8D", "%8E", "%8F", "%90", "%91", "%92", "%93", "%94", "%95", "%96", "%97", "%98", "%99", "%9A", "%9B", "%9C", "%9D", "%9E", "%9F", "%A0", "%A1", "%A2", "%A3", "%A4", "%A5", "%A6", "%A7", "%A8", "%A9", "%AA", "%AB", "%AC", "%AD", "%AE", "%AF", "%B0", "%B1", "%B2", "%B3", "%B4", "%B5", "%B6", "%B7", "%B8", "%B9", "%BA", "%BB", "%BC", "%BD", "%BE", "%BF", "%C0", "%C1", "%C2", "%C3", "%C4", "%C5", "%C6", "%C7", "%C8", "%C9", "%CA", "%CB", "%CC", "%CD", "%CE", "%CF", "%D0", "%D1", "%D2", "%D3", "%D4", "%D5", "%D6", "%D7", "%D8", "%D9", "%DA", "%DB", "%DC", "%DD", "%DE", "%DF", "%E0", "%E1", "%E2", "%E3", "%E4", "%E5", "%E6", "%E7", "%E8", "%E9", "%EA", "%EB", "%EC", "%ED", "%EE", "%EF", "%F0", "%F1", "%F2", "%F3", "%F4", "%F5", "%F6", "%F7", "%F8", "%F9", "%FA", "%FB", "%FC", "%FD", "%FE", "%FF" }; /** * Encode a string according to RFC 1738. * <p/> * <quote> "...Only alphanumerics [0-9a-zA-Z], the special characters "$-_.+!*'()," [not including the quotes - ed], * and reserved characters used for their reserved purposes may be used unencoded within a URL."</quote> * <p/> * <ul> <li><p>The ASCII characters 'a' through 'z', 'A' through 'Z', and '0' through '9' remain the same. * <p/> * <li><p>The unreserved characters - _ . ! ~ * ' ( ) remain the same. * <p/> * <li><p>All other ASCII characters are converted into the 3-character string "%xy", where xy is the two-digit * hexadecimal representation of the character code * <p/> * <li><p>All non-ASCII characters are encoded in two steps: first to a sequence of 2 or 3 bytes, using the UTF-8 * algorithm; secondly each of these bytes is encoded as "%xx". </ul> * * @param s The string to be encoded * @return The encoded string */ public static String encodeUTF8(final String s) { final StringBuffer sbuf = new StringBuffer(); final char[] sChars = s.toCharArray(); final int len = sChars.length; for (int i = 0; i < len; i++) { final int ch = sChars[i]; if ('A' <= ch && ch <= 'Z') { // 'A'..'Z' sbuf.append((char) ch); } else if ('a' <= ch && ch <= 'z') { // 'a'..'z' sbuf.append((char) ch); } else if ('0' <= ch && ch <= '9') { // '0'..'9' sbuf.append((char) ch); } else if (ch == '-' || ch == '_' // unreserved || ch == '.' || ch == '!' || ch == '~' || ch == '*' || ch == '\'' || ch == '(' || ch == ')') { sbuf.append((char) ch); } else if (ch <= 0x007f) { // other ASCII sbuf.append(hex[ch]); } else if (ch <= 0x07FF) { // non-ASCII <= 0x7FF sbuf.append(hex[0xc0 | (ch >> 6)]); sbuf.append(hex[0x80 | (ch & 0x3F)]); } else { // 0x7FF < ch <= 0xFFFF sbuf.append(hex[0xe0 | (ch >> 12)]); sbuf.append(hex[0x80 | ((ch >> 6) & 0x3F)]); sbuf.append(hex[0x80 | (ch & 0x3F)]); } } return sbuf.toString(); } /** * Encodes a byte-array. The array is expected to contain ASCII characters, or the result may not be valid. * * @param s the byte array * @return the array as encoded string. */ private static String encodeBytes(final byte[] s) { final StringBuffer sbuf = new StringBuffer(); final int len = s.length; for (int i = 0; i < len; i++) { final int ch = (s[i] & 0xff); if ('A' <= ch && ch <= 'Z') { // 'A'..'Z' sbuf.append((char) ch); } else if ('a' <= ch && ch <= 'z') { // 'a'..'z' sbuf.append((char) ch); } else if ('0' <= ch && ch <= '9') { // '0'..'9' sbuf.append((char) ch); } else if (ch == '-' || ch == '_' // unreserved || ch == '.' || ch == '!' || ch == '~' || ch == '*' || ch == '\'' || ch == '(' || ch == ')') { sbuf.append((char) ch); } else { // other ASCII sbuf.append(hex[ch]); } } return sbuf.toString(); } /** * Encodes thh given string using the provided encoding. The encoding must be a valid Java-encoding. * * @param s the string that should be encoded. * @param encoding the encoding to tranform the string into bytes. * @return the encoded string. * @throws UnsupportedEncodingException if the specified encoding is not recognized. */ public static String encode(final String s, final String encoding) throws UnsupportedEncodingException { if ("utf-8".equalsIgnoreCase(encoding)) { return encodeUTF8(s); } return encodeBytes(s.getBytes(encoding)); } /** * Decodes the given string using the provided encoding. The encoding must be a valid * Java-encoding. * * @param s the string that should be encoded. * @param encoding the encoding to tranform the bytes into a string. * @return the encoded string. * @throws UnsupportedEncodingException if the specified encoding is not recognized. */ public static String decode(final String s, final String encoding) throws UnsupportedEncodingException { if ("utf-8".equalsIgnoreCase(encoding)) { return decodeUTF(s); } // the resulting string will never be greater than the encoded string final byte[] result = new byte[s.length()]; final char[] chars = s.toCharArray(); int position = 0; for (int i = 0; i < chars.length; i++) { final char ch = chars[i]; final int b; switch (ch) { case '%': final char lch = s.charAt(++i); final int hb = (Character.isDigit(lch) ? lch - '0' : 10 + Character.toLowerCase(lch) - 'a') & 0xF; final char hch = s.charAt(++i); final int lb = (Character.isDigit(hch) ? hch - '0' : 10 + Character.toLowerCase(hch) - 'a') & 0xF; b = (hb << 4) | lb; break; case '+': b = ' '; break; default: b = ch; } result[position] = (byte) b; position += 1; } return new String(result, 0, position, encoding); } /** * Decodes the given string using the encoding UTF-8. * * @param s the string that should be encoded. * @return the encoded string. */ public static String decodeUTF(final String s) { final StringBuffer sbuf = new StringBuffer(); final char[] chars = s.toCharArray(); final int l = chars.length; int sumb = 0; for (int i = 0, more = -1; i < l; i++) { /* Get next byte b from URL segment s */ final int ch = chars[i]; final int b; switch (ch) { case '%': final char lch = s.charAt(++i); final int hb = (Character.isDigit(lch) ? lch - '0' : 10 + Character.toLowerCase(lch) - 'a') & 0xF; final char hch = s.charAt(++i); final int lb = (Character.isDigit(hch) ? hch - '0' : 10 + Character.toLowerCase(hch) - 'a') & 0xF; b = (hb << 4) | lb; break; case '+': b = ' '; break; default: b = ch; } /* Decode byte b as UTF-8, sumb collects incomplete chars */ if ((b & 0xc0) == 0x80) { // 10xxxxxx (continuation byte) sumb = (sumb << 6) | (b & 0x3f); // Add 6 bits to sumb if (--more == 0) { sbuf.append((char) sumb); // Add char to sbuf } } else if ((b & 0x80) == 0x00) { // 0xxxxxxx (yields 7 bits) sbuf.append((char) b); // Store in sbuf } else if ((b & 0xe0) == 0xc0) { // 110xxxxx (yields 5 bits) sumb = b & 0x1f; more = 1; // Expect 1 more byte } else if ((b & 0xf0) == 0xe0) { // 1110xxxx (yields 4 bits) sumb = b & 0x0f; more = 2; // Expect 2 more bytes } else if ((b & 0xf8) == 0xf0) { // 11110xxx (yields 3 bits) sumb = b & 0x07; more = 3; // Expect 3 more bytes } else if ((b & 0xfc) == 0xf8) { // 111110xx (yields 2 bits) sumb = b & 0x03; more = 4; // Expect 4 more bytes } else /*if ((b & 0xfe) == 0xfc)*/ { // 1111110x (yields 1 bit) sumb = b & 0x01; more = 5; // Expect 5 more bytes } /* We don't test if the UTF-8 encoding is well-formed */ } return sbuf.toString(); } }