这是我用于哈希的:

String pass = "password";

MessageDigest messageDigest = MessageDigest.getInstance("SHA-256");
byte hashBytes[] = messageDigest.digest(pass.getBytes(StandardCharsets.UTF_8));
BigInteger noHash = new BigInteger(1, hashBytes);
String hashStr = noHash.toString(16);

输出:5e884898da28047151d0e56f8dc6292773603d0d6aabbdd62a11ef721d1542d8

在Java 8中

import java.nio.charset.StandardCharsets;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.Scanner;
import javax.xml.bind.DatatypeConverter;


Scanner scanner = new Scanner(System.in);
String password = scanner.nextLine();
scanner.close();

MessageDigest digest = null;
try {
    digest = MessageDigest.getInstance("SHA-256");
} catch (NoSuchAlgorithmException e) {
    // TODO Auto-generated catch block
    e.printStackTrace();
}
byte[] hash = digest.digest(password.getBytes(StandardCharsets.UTF_8));
String encoded = DatatypeConverter.printHexBinary(hash);        
System.out.println(encoded.toLowerCase());

另一个替代方案是Guava，它有一套易于使用的哈希实用程序。例如，使用SHA256作为十六进制字符串来哈希字符串，你可以简单地这样做:

final String hashed = Hashing.sha256()
        .hashString("your input", StandardCharsets.UTF_8)
        .toString();

这是我用于哈希的:

String pass = "password";

MessageDigest messageDigest = MessageDigest.getInstance("SHA-256");
byte hashBytes[] = messageDigest.digest(pass.getBytes(StandardCharsets.UTF_8));
BigInteger noHash = new BigInteger(1, hashBytes);
String hashStr = noHash.toString(16);

输出:5e884898da28047151d0e56f8dc6292773603d0d6aabbdd62a11ef721d1542d8

我认为最简单的解决方案是使用Apache Common Codec:

String sha256hex = org.apache.commons.codec.digest.DigestUtils.sha256Hex(stringText);   

private static String getMessageDigest(String message, String algorithm) {
 MessageDigest digest;
 try {
  digest = MessageDigest.getInstance(algorithm);
  byte data[] = digest.digest(message.getBytes("UTF-8"));
  return convertByteArrayToHexString(data);
 } catch (NoSuchAlgorithmException | UnsupportedEncodingException e) {
  // TODO Auto-generated catch block
  e.printStackTrace();
 }
 return null;
}

你可以像下面这样用不同的算法调用上面的方法。

getMessageDigest(message, "MD5");
getMessageDigest(message, "SHA-256");
getMessageDigest(message, "SHA-1");

您可以参考此链接以获得完整的应用程序。