Why do I get a larger array when I try to read a 'byte-array' from my web service using the 'createClassFromWsdl' interface in MATLAB 7.12 (R2011a)?

I have a webservice that returns some data in the form of a byte-array in both my Java and C# client interfaces. However, if I read that same data into MATLAB using the 'createClassFromWsdl' interface, I get data whose size is larger than the expected array. Moreover, it consists of different data.

Answer 1

[MathWorks Support Team]

MATLAB returns the base64 encoded byte stream for any data that is sent over the SOAP message. Unlike C# or Java clients which interface to the webservice, MATLAB does not convert this data back to a binary byte array.

Base64 encoding takes every 3 bytes (24 bits) and encodes them into 4 bytes with 6 bits of data per byte. Each of these 4 bytes comes from a 64-byte dictionary of regular characters (e.g. A-Z,a-z, 0-9, / etc).

To get the raw byte data, manually decode this Base64 encoded data.

A small example of how to do this within MATLAB is shown below:

%Import Java

import java.lang.String;

%Import the base64 encoder object

encoder = org.apache.commons.codec.binary.Base64;

% Create a sample Base64 encoded string

bs64data = '7tyg546bf0a2316dhvber345' ; 

% Create Java String 

JavaString = String(bs64data);

% Extract the Bytes from this String

ByteFromString = JavaString.getBytes();

% Perform the Base64 Decoding - Output is int8 data format

DecodedBytes = encoder.decodeBase64(ByteFromString);