将字节数组转换为base64字符串Java

Question

Trying to convert a byte[] to base64 string using org.apache.commons.codec.binary.Base64 ..For this my java code looks like:

 base64String = Base64.encodeBase64URLSafeString(myByteArray);

But what i see is some invalid characters in the generated base64 string..

Why do I see these ____ lines in my generated base64 String? Is it a valid string? Note the length of the generated string is dividable by four.

Answer 1

have you tried with the encodeBase64String method instead of using encodeBase64URLSafeString ?

encodeBase64URLSafeString:

Encodes binary data using a URL-safe variation of the base64 algorithm but does not chunk the output. The url-safe variation emits - and _ instead of + and / characters.

encodeBase64String:

Encodes binary data using the base64 algorithm but does not chunk the output. NOTE: We changed the behaviour of this method from multi-line chunking (commons-codec-1.4) to single-line non-chunking (commons-codec-1.5).

source : org.apache.commons.codec.binary.Base64 javadoc

Answer 2

This may be helpful

sun.misc.BASE64Encoder encoder = new sun.misc.BASE64Encoder();
encoder.encode(byteArray);

Answer 3

使用

String sCert = javax.xml.bind.DatatypeConverter.printBase64Binary(pk); 

Answer 4

you've got (at least) two flavours of base64, the original one using '+' and '/' in addition to alphanumeric characters, and the "url safe" one, using "-" and "_" so that the content can be enclosed in a URL (or used as a filename, btw).

It looks like you're using a base64 encoder that has been turned into "url-safe mode".

apache's javadoc for URLSafeString()

Oh, and '_' being the last character of the base64 alphabet, seeing strings of "____" means you've been encoding chunks of 0xffffff ... , just like seeing "AAAAAA" means there's a lot of consecutive zeroes.

If you want to be convinced that it's a normal case, just pick your favourite hexadecimal dumper/editor and check what your binary input looked like.

Answer 5

By the below process you can convert byte array to Base64

 // Convert a byte array to base64 string
    byte[] bytearray= new byte[]{0x12, 0x23};
    String s = new sun.misc.BASE64Encoder().encode(bytearray);

    // Convert base64 string to a byte array
    bytearray = new sun.misc.BASE64Decoder().decodeBuffer(s);

Edit:

Please check for guide below link commons apache