liquibase.util.MD5Util Maven / Gradle / Ivy
package liquibase.util;
import liquibase.configuration.GlobalConfiguration;
import liquibase.configuration.LiquibaseConfiguration;
import liquibase.exception.UnexpectedLiquibaseException;
import liquibase.logging.LogService;
import liquibase.logging.LogType;
import java.io.InputStream;
import java.security.DigestInputStream;
import java.security.MessageDigest;
/**
* Generates md5-sums based on a string.
*/
public class MD5Util {
/**
* Used to build output as Hex
*/
private static final char[] DIGITS_LOWER = {
'0', '1', '2', '3', '4', '5', '6', '7',
'8', '9', 'a', 'b', 'c', 'd', 'e', 'f'
};
public static String computeMD5(String input) {
if (input == null) {
return null;
}
MessageDigest digest;
try {
digest = MessageDigest.getInstance("MD5");
digest.update(input.getBytes(LiquibaseConfiguration.getInstance().getConfiguration(GlobalConfiguration.class).getOutputEncoding()));
} catch (Exception e) {
throw new UnexpectedLiquibaseException(e);
}
byte[] digestBytes = digest.digest();
String returnString = new String(encodeHex(digestBytes));
String inputToLog = input;
if (inputToLog.length() > 500) {
inputToLog = inputToLog.substring(0, 500)+"... [truncated in log]";
}
LogService.getLog(MD5Util.class).debug(LogType.LOG, "Computed checksum for "+inputToLog+" as "+returnString);
return returnString;
}
public static String computeMD5(InputStream stream) {
MessageDigest digest;
try {
digest = MessageDigest.getInstance("MD5");
DigestInputStream digestStream = new DigestInputStream(stream, digest);
byte[] buf = new byte[20480];
while (digestStream.read(buf) != -1) {
; //digest is updating
}
} catch (Exception e) {
throw new RuntimeException(e);
}
byte[] digestBytes = digest.digest();
String returnString = new String(encodeHex(digestBytes));
LogService.getLog(MD5Util.class).debug(LogType.LOG, "Computed checksum for inputStream as "+returnString);
return returnString;
}
/**
* Converts an array of bytes into an array of characters representing the hexadecimal values of each byte in order.
* The returned array will be double the length of the passed array, as it takes two characters to represent any
* given byte.
*
* @param data
* a byte[] to convert to Hex characters
* @return A char[] containing hexadecimal characters
*/
private static char[] encodeHex(byte[] data) {
int l = data.length;
char[] out = new char[l << 1];
// two characters form the hex value.
for (int i = 0, j = 0; i < l; i++) {
out[j++] = DIGITS_LOWER[(0xF0 & data[i]) >>> 4];
out[j++] = DIGITS_LOWER[0x0F & data[i]];
}
return out;
}
}