Importing SVN archives - B6M1

legacyworlds-utils/src/main/java/com/deepclone/lw/utils/DigestHelper.java

@@ -0,0 +1,56 @@
+package com.deepclone.lw.utils;
+
+
+import java.io.UnsupportedEncodingException;
+import java.security.MessageDigest;
+import java.security.NoSuchAlgorithmException;
+
+import org.apache.commons.codec.binary.Hex;
+
+
+
+/**
+ * This class provides a static method which simplies computing hex-encoded digests of strings using
+ * some hashing algorithm.
+ * 
+ * @author tseeker
+ */
+public final class DigestHelper
+{
+
+	private DigestHelper( )
+	{
+		// EMPTY
+	}
+
+
+	/**
+	 * This method computes a hex-encoded digest of a string using the specified algorithm.
+	 * 
+	 * @param algo
+	 *            the digest algorithm to use
+	 * @param source
+	 *            the string to digest
+	 * @return the hex-encoded digest
+	 */
+	public static String digest( String algo , String source )
+	{
+		// Create digest
+		MessageDigest digestAlgorithm;
+		try {
+			digestAlgorithm = MessageDigest.getInstance( algo );
+		} catch ( NoSuchAlgorithmException e ) {
+			throw new RuntimeException( "'" + algo + "' digest not supported" );
+		}
+		// Add data
+		try {
+			digestAlgorithm.update( source.getBytes( "UTF-8" ) );
+		} catch ( UnsupportedEncodingException e ) {
+			throw new RuntimeException( "UTF-8 not supported? I must be dreaming." );
+		}
+		// Compute digest and return its hexadecimal encoding
+		byte[] digest = digestAlgorithm.digest( );
+		return Hex.encodeHexString( digest );
+	}
+
+}