Encoding as Base64 in Java

I need to encode some data in the Base64 encoding in Java. How do I do that? What is the name of the class that provides a Base64 encoder?

I tried to use the sun.misc.BASE64Encoder class, without success. I have the following line of Java 7 code:

wr.write(new sun.misc.BASE64Encoder().encode(buf));

I'm using Eclipse. Eclipse marks this line as an error. I imported the required libraries:

import sun.misc.BASE64Encoder;
import sun.misc.BASE64Decoder;

But again, both of them are shown as errors. I found a similar post here.

I used Apache Commons as the solution suggested by including:

import org.apache.commons.*;

and importing the JAR files downloaded from: http://commons.apache.org/codec/

But the problem still exists. Eclipse still shows the errors previously mentioned. What should I do?

Solution 1:

You need to change the import of your class:

import org.apache.commons.codec.binary.Base64;

And then change your class to use the Base64 class.

Here's some example code:

byte[] encodedBytes = Base64.encodeBase64("Test".getBytes());
System.out.println("encodedBytes " + new String(encodedBytes));
byte[] decodedBytes = Base64.decodeBase64(encodedBytes);
System.out.println("decodedBytes " + new String(decodedBytes));

Then read why you shouldn't use sun.* packages.

Update (2016-12-16)

You can now use java.util.Base64 with Java 8. First, import it as you normally do:

import java.util.Base64;

Then use the Base64 static methods as follows:

byte[] encodedBytes = Base64.getEncoder().encode("Test".getBytes());
System.out.println("encodedBytes " + new String(encodedBytes));
byte[] decodedBytes = Base64.getDecoder().decode(encodedBytes);
System.out.println("decodedBytes " + new String(decodedBytes));

If you directly want to encode string and get the result as encoded string, you can use this:

String encodeBytes = Base64.getEncoder().encodeToString((userName + ":" + password).getBytes());

See Java documentation for Base64 for more.

Solution 2:

Use Java 8's never-too-late-to-join-in-the-fun class: java.util.Base64

new String(Base64.getEncoder().encode(bytes));

Solution 3:

In Java 8 it can be done as: Base64.getEncoder().encodeToString(string.getBytes(StandardCharsets.UTF_8))

Here is a short, self-contained complete example:

import java.nio.charset.StandardCharsets;
import java.util.Base64;

public class Temp {
    public static void main(String... args) throws Exception {
        final String s = "old crow medicine show";
        final byte[] authBytes = s.getBytes(StandardCharsets.UTF_8);
        final String encoded = Base64.getEncoder().encodeToString(authBytes);
        System.out.println(s + " => " + encoded);
    }
}

Output:

old crow medicine show => b2xkIGNyb3cgbWVkaWNpbmUgc2hvdw==