Base64 decode

[Pichdude]

Hi,

I am using these two methods to make a Base64-encoded String from a regular text. First convert it to a byte[] and then to Base64 encoding.

String originalText = "abc123";

String base64Text = toBase64(originalText);

private String toBase64(String s) throws SystemException {
	return new BASE64Encoder().encode(toByteArray(s));
}

private byte[] toByteArray(String s) throws SystemException {
	try {
		return s.getBytes("UTF-8");
	} catch (UnsupportedEncodingException e) {
		SystemException se = new SystemException();
		throw se;
	}
}

My problem is, later on I need to use the original text again. Can anybody help me on how I get back from the Base64-encoded text "YWJjMTIz" to "abc123"?

 

[Diancecht]

new Base64Decoder().decode()?

Cheers,
Dian

 

[Pichdude]

From where do i get that class and method?

Regards

Per

 

[Diancecht]

Where did you get your encoder?

Cheers,
Dian

 

[Pichdude]

Nevermind.

I think my problem is that before I Base64-encode I have to make the String into a byte[], and than later when I decode the Base64-encoded String i receive the byte[]. But then I want to go back from the byte[] to the exact original String ("acb123"). How do I do that?

Regards

Per


Ps. I use:
sun.misc.BASE64Encoder().encode(byte[] arg)
sun.misc.BASE64Decoder().decodeBuffer(String arg)

Method decodeBuffer() returns a byte[]. Can find any methods for encoding and decoding that takes and returns String.

 

[Diancecht]

Ah, I see, I wasn't understanding the question.

You just need the constructor for String object

byte[] myBytes;
String myString = new String(myBytes,0,myBytes.length,"UTF-8");

Cheers,
Dian

 

[Pichdude]

You rule!

Thanks a lot.

 

[Diancecht]

I know

Btw, remember what I told you in the other post abut the standard Java forum.

Cheers,
Dian

 

[Pichdude]

Has any body heard if there is a max size of how long the String can be that is to BASE64 encoded by sun.misc.BASE64Encoder?

 

[sedj]

I don't believe there is a max size per se in the Base64Encoder class.

Some of my code successfully encodes/decodes up to 5/6/7 MBs ...

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[Pichdude]

After about 56 to 57 characters i get "\r\n" inserted to the code. After the next 56-57 characters I get it again, and so on.. Have you any idea why?

Regards

 

[sedj]

Yeah, I get that too, I wouldn't worry about it - it'll make no difference (or shouldn't) to the Decoder, because Base64 does not include control characters such as CRLF.

--------------------------------------------------
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http://www.primrose.org.uk

 

[Pichdude]

Aha, then there is nothing wrong with my code. The problem is that i publish the base64 encoded string on a webpage, and there the \r\n makes a line break and gives me problem. But for now I just replace them characters in the base64 encoded string with nothing, and problem solved.

 

[Pichdude]

It a appears that BASE64 does this to provide nice print outs and it should not effect the code. But since it does for me do anybody know if there is a way to set after which character BAS64 should insert these line breaks? If so, then I could set it to 100 and it would not be a problem for me, since my Strings are not longer than around 80.

Regards

Pichdude

 

[sedj]

Just do :

String base64encoded = Base64.encode...
base64encoded = base64encoded.replaceAll("\r\n", "");

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http://www.primrose.org.uk

 

[Pichdude]

Yes that is what I do. But that is a rather "ugly" solution. If it where possible to control it from the BASE64Encoder it would be more correct.

 

[sedj]

Well that it might my good fellow, but considering that the class BASE64Decoder is neither documented, nor is the source shipped, I don't like your chances.

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http://www.primrose.org.uk