edu.mit.simile.babel.util.Util Maven / Gradle / Ivy
/*
* (c) Copyright The SIMILE Project 2003-2004. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. 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.
*
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
*
*/
package edu.mit.simile.babel.util;
import java.io.*;
import java.util.*;
import java.security.*;
import org.apache.commons.codec.net.URLCodec;
public final class Util {
public static String join(String[] strings, char separator) {
StringBuffer sb = new StringBuffer();
for (int i = 0; i < strings.length; i++) {
if (i > 0) {
sb.append(separator);
}
sb.append(strings[i]);
}
return sb.toString();
}
/**
* Computes the MD5 message digest of an InputStream
* and returns it as a hexidecimal String. The caller is responsible
* for calling the close() method of
* message.
* @return A String that is 32
* characters long consisting of digits and the lower case alphabetic characters a-f.
*/
public static String computeMD5(InputStream message)
throws IOException {
int ch;
ByteArrayOutputStream out = new ByteArrayOutputStream();
while ((ch = message.read()) != -1) {
out.write(ch);
}
out.close();
return computeMD5(out.toByteArray());
}
/**
* Computes the MD5 message digest of a String and
* returns it as a hexidecimal String. Since Java strings are
* Unicode characters, the string is first encoded into UTF-8, which
* defines a unique octet sequence for the string. The returned
* String is 32 characters long and alphabetic
* characters a-f are lower-case.
*/
public static String computeMD5(java.lang.String message) {
try {
return computeMD5(message.getBytes("UTF8"));
} catch (UnsupportedEncodingException e) {
return null;
} // won't happen
}
/**
* Computes the MD5 message digest of a Byte[] and
* returns it as a hexidecimal String. The returned
* String is 32 characters long and alphabetic
* characters a-f are lower-case.
*/
public static String computeMD5(byte[] message) {
try {
MessageDigest md5 = MessageDigest.getInstance("MD5");
md5.reset();
md5.update(message);
byte[] digest = md5.digest();
StringBuffer sb = new StringBuffer();
for (int i = 0; i < digest.length; i++) {
if ((0xff & digest[i]) < 0x10)
sb.append('0');
sb.append(Integer.toHexString(0xff & digest[i]));
}
return (sb.toString());
} catch (NoSuchAlgorithmException e) {
return null;
} // won't happen
}
//////////////////////////////////////////////////////////////////////
/** Converts a string into a canonical form for the purpose
* embedding into URIs. Permissible characters are defined in
* section 2.2 of RFC 2141,
* URN Syntax */
public static String toURI(String input) {
try {
byte[] bytes = input.getBytes("UTF8");
StringBuffer sb = new StringBuffer(2 * input.length());
for (int i = 0; i < bytes.length; i++) {
byte c = bytes[i];
if ((('a' <= c) && (c <= 'z'))
|| (('@' <= c) && (c <= 'Z'))
|| (('0' <= c) && (c <= ';'))
|| (('\'' <= c) && (c <= '.'))
|| (c == '$')
|| (c == '=')
|| (c == '_')
|| (c == '!')) {
sb.append((char) c);
} else {
sb.append(((0xff & bytes[i]) < 0x10) ? "%0" : "%");
sb.append(
Integer.toHexString(0xff & bytes[i]).toUpperCase());
}
}
return sb.toString();
} catch (UnsupportedEncodingException e) {
return null;
} // won't happen
}
//////////////////////////////////////////////////////////////////////
/** Converts a string into a canonical form for the purpose
* embedding into RDF Literals. Permissible characters are valid
* XML characters, which is everything greater than \u0020 in addition
* to: \u0009 or "\t", \u000A or "\n", and \u000D or "\r". */
public static String toLiteral(String input) {
boolean good = true;
int len = input.length();
for (int i = 0; i < len; i++) {
int c = (int) input.charAt(i);
if (c < 0x0020 && c != 0x0009 && c != 0x000a && c != 0x000d)
good = false;
}
if (good)
return input;
// Otherwise, we've got a nasty one.
StringBuffer sb = new StringBuffer(len);
for (int i = 0; i < len; i++) {
char c = input.charAt(i);
if (c >= 0x0020 || c == 0x0009 || c == 0x000a || c == 0x000d)
sb.append(c);
}
return sb.toString();
}
public static String generateUID() {
Random rand = new Random();
StringBuffer sb = new StringBuffer(16);
for (int i = 0; i < 16; i++)
sb.append("0123456789ABCDEF".charAt(rand.nextInt(16)));
return sb.toString();
}
final static String s_urlEncoding = "UTF-8";
final static URLCodec s_codec = new URLCodec();
final static public String decode(String s) {
try {
return s_codec.decode(s, s_urlEncoding);
} catch (Exception e) {
throw new RuntimeException("Exception decoding " + s + " with " + s_urlEncoding + " encoding.");
}
}
final static public String encode(String s) {
try {
return s_codec.encode(s, s_urlEncoding);
} catch (Exception e) {
throw new RuntimeException("Exception decoding " + s + " with " + s_urlEncoding + " encoding.");
}
}
}
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