import java.io.IOException;
import java.security.MessageDigest;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;
import java.util.StringTokenizer;
/**
* String Utility Class This is used to encode passwords programmatically
*
*
*
*
*
* @author Matt Raible
*/
public class StringUtils {
//~ Static fields/initializers
//~ Methods
/**
* Encode a string using algorithm specified in web.xml and return the
* resulting encrypted password. If exception, the plain credentials
* string is returned
*
* @param password Password or other credentials to use in authenticating
* this username
* @param algorithm Algorithm used to do the digest
*
* @return encypted password based on the algorithm.
*/
public static String encodePassword(String password, String algorithm) {
byte[] unencodedPassword = password.getBytes();
MessageDigest md = null;
try {
// first create an instance, given the provider
md = MessageDigest.getInstance(algorithm);
} catch (Exception e) {
System.out.println(e);
return password;
}
md.reset();
// call the update method one or more times
// (useful when you don't know the size of your data, eg. stream)
md.update(unencodedPassword);
// now calculate the hash
byte[] encodedPassword = md.digest();
StringBuffer buf = new StringBuffer();
for (int i = 0; i < encodedPassword.length; i++) {
if ((encodedPassword[i] & 0xff) < 0x10) {
buf.append("0");
}
buf.append(Long.toString(encodedPassword[i] & 0xff, 16));
}
return buf.toString();
}
/**
* Encode a string using Base64 encoding. Used when storing passwords
* as cookies.
*
* This is weak encoding in that anyone can use the decodeString
* routine to reverse the encoding.
*
* @param str
* @return String
*/
public static String encodeString(String str) {
sun.misc.BASE64Encoder encoder = new sun.misc.BASE64Encoder();
return encoder.encodeBuffer(str.getBytes()).trim();
}
/**
* Decode a string using Base64 encoding.
*
* @param str
* @return String
*/
public static String decodeString(String str) {
sun.misc.BASE64Decoder dec = new sun.misc.BASE64Decoder();
try {
return new String(dec.decodeBuffer(str));
} catch (IOException io) {
throw new RuntimeException(io.getMessage(), io.getCause());
}
}
public static String[] tokenizeToStringArray(String str, String delimiters) {
return tokenizeToStringArray(str, delimiters, true, true);
}
public static String[] tokenizeToStringArray(
String str, String delimiters, boolean trimTokens, boolean ignoreEmptyTokens) {
StringTokenizer st = new StringTokenizer(str, delimiters);
List tokens = new ArrayList();
while (st.hasMoreTokens()) {
String token = st.nextToken();
if (trimTokens) {
token = token.trim();
}
if (!ignoreEmptyTokens || token.length() > 0) {
tokens.add(token);
}
}
return toStringArray(tokens);
}
public static String[] toStringArray(Collection collection) {
if (collection == null) {
return null;
}
return (String[]) collection.toArray(new String[collection.size()]);
}
public static boolean isEmpty(String str) {
if (str == null || "".equals(str.trim())) {
return true;
}
return false;
}
public static boolean isNotEmpty(String str) {
return !isEmpty(str);
}
}