Date: 2022oct12
Update: 2025oct9
Language: Java
Q. Java: Make a SHA-256 hash (digest)
A. Here is a full example:
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
class Demo {
public static String toHexString(final byte[] ba) {
final StringBuilder sb = new StringBuilder();
for(int i = 0; i < ba.length; i++) {
sb.append(String.format("%02x", ba[i]));
}
return sb.toString();
}
public static String makeSha256(final String thingOne, final String thingTwo) {
MessageDigest md;
try {
md = MessageDigest.getInstance("SHA-256");
}
catch (NoSuchAlgorithmException ex) {
// Every implementation of the Java platform is required to support
// the following standard MessageDigest algorithms: MD5 SHA-1 SHA-256
return "";
}
md.update(thingOne.getBytes());
md.update(thingTwo.getBytes());
final byte byteData[] = md.digest();
return toHexString(byteData);
}
public static final void main(String[] args) {
String sum = makeSha256("hello", "world");
System.out.println("sha256=" + sum);
}
}
Output:
sha256=936a185caaa266bb9cbe981e9e05cb78cd732b0b3280eb944412bb6f8f8f07af