Below is the syntax highlighted version of OneWay.java
from §3.4 Hash Tables.
/****************************************************************************** * Compilation: javac OneWay.java * Execution: java OneWay password * Dependencies: StdOut.java * * Comptue the SHA1 of the command line argument. * * * % java OneWay "The quick brown fox jumps over the lazy dog" * 2fd4e1c6 7a2d28fc ed849ee1 bb76e739 1b93eb12 * * % java OneWay test * a94a8fe5 ccb19ba6 1c4c0873 d391e987 982fbbd3 * * % java OneWay "" * da39a3ee 5e6b4b0d 3255bfef 95601890 afd80709 * ******************************************************************************/ import java.security.MessageDigest; public final class OneWay { public static void main(String[] args) { String password = args[0]; // get SHA1 algorithm object and compute SHA1 of password MessageDigest sha1; byte[] bytes; try { sha1 = MessageDigest.getInstance("SHA1"); bytes = sha1.digest(password.getBytes("ISO-8859-1")); } catch (java.security.NoSuchAlgorithmException e) { StdOut.println(e); return; } catch (java.io.UnsupportedEncodingException e) { StdOut.println(e); return; } // convert bytes to hex, careful to handle leading 0s and 2s complement String hex = "0123456789abcdef"; for (int i = 0; i < bytes.length; i++) { if (i % 4 == 0) StdOut.print(" "); StdOut.print(hex.charAt((bytes[i] & 0xF0) >> 4)); StdOut.print(hex.charAt((bytes[i] & 0x0F) >> 0)); } StdOut.println(); } }