How to Base64 encode a Java object using org.apach

Question

I've been trying to do an object serialization and Base64 encode the result. It works with Sun's lib:

Bean01 bean01 = new Bean01();
bean01.setDefaultValues();
ByteArrayOutputStream baos = new ByteArrayOutputStream();
new ObjectOutputStream( baos ).writeObject( bean01 );
System.out.println(Base64.encode(baos.toByteArray()));

This works fine. However, I would like to do the same using org.apache.commons.codec.binary.base64, but this does not return the same string:

System.out.println(org.apache.commons.codec.binary.Base64.encodeBase64(baos.toByteArray()));

What would be the correct way to achieve the correct Base64 encoding of a byteArray using Apache's encoder?

Answer 1

Actually the commons-codec version and specific Sun internal version you are using do give the same results. I think you thought they were giving different versions because you are implicitly calling toString() on an array when you do:

System.out.println(org.apache.commons.codec.binary.Base64.encodeBase64(baos.toByteArray()));

which is definitely does not print out the array contents. Instead, that will only print out the address of the array reference.

I've written the following program to test the encoders against each other. You'll see from the output below that the give the same results:

import java.util.Random;

public class Base64Stuff
{
    public static void main(String[] args) {
        Random random = new Random();
        byte[] randomBytes = new byte[32];
        random.nextBytes(randomBytes);

        String internalVersion = com.sun.org.apache.xerces.internal.impl.dv.util.Base64.encode(randomBytes);
        byte[] apacheBytes =  org.apache.commons.codec.binary.Base64.encodeBase64(randomBytes);
        String fromApacheBytes = new String(apacheBytes);

        System.out.println("Internal length = " + internalVersion.length());
        System.out.println("Apache bytes len= " + fromApacheBytes.length());
        System.out.println("Internal version = |" + internalVersion + "|");
        System.out.println("Apache bytes     = |" + fromApacheBytes + "|");
        System.out.println("internal equal apache bytes?: " + internalVersion.equals(fromApacheBytes));
    }
}

And here's the output from a run of it:

Internal length = 44
Apache bytes len= 44
Internal version = |Kf0JBpbxCfXutxjveYs8CXMsFpQYgkllcHHzJJsz9+g=|
Apache bytes     = |Kf0JBpbxCfXutxjveYs8CXMsFpQYgkllcHHzJJsz9+g=|
internal equal apache bytes?: true

Answer 2

From commons-codec home page:

Codec was formed as an attempt to focus development effort on one definitive implementation of the Base64 encoder. At the time of Codec's proposal, there were approximately 34 different Java classes that dealt with Base64 encoding spread over the Foundation's CVS repository. Developers in the Jakarta Tomcat project had implemented an original version of the Base64 codec which had been copied by the Commons HttpClient and Apache XML project's XML-RPC subproject. After almost one year, the two forked versions of Base64 had significantly diverged from one another. XML-RPC had applied numerous fixes and patches which were not applied to the Commons HttpClient Base64. Different subprojects had differing implementations at various levels of compliance with the RFC 2045.

I think your problem is the "various level" of compliance.

My advice: choose one base64 encoder/decoder and stick to it