From yan...@google.com on March 26, 2012 11:27:03

External references, such as a standards document, or specification? https://code.google.com/apis/discovery/v1/reference.html#type-and-format-summary Java environments (e.g. Java 6, Android 2.3, App Engine, or All)? All Please describe the feature requested. Some Google API services may include a data type that is a base64-encoded string of bytes. It is the data type listed in the above reference link as type value "string" and format value "byte". It is not documented there, but apparently this is the URL-safe alphabet with padding. We should make it easier to parse/serialize that format.

The catch is the lower-level JSON model doesn't have this support built-in. The simplest solution is to still use Java String as the data type of the field, but provide accessors that handle that conversion and work with byte[].

So one option:

public class A {
@key private String data;
public byte[] getData() {
return Base64.decodeBase64(data);
}
public void setData(byte[] data) {
this.data = Base64.encodeBase64URLSafeString(data);
}
}

Another option:

public class A {
@key private String data;
public String getData() {
return data;
}
public void setData(String data) {
this.data = data;
}
public byte[] decodeData() {
return Base64.decodeBase64(data);
}
public void encodeData(byte[] data) {
this.data = Base64.encodeBase64URLSafeString(data);
}
}

(or something along these lines)

Original issue: http://code.google.com/p/google-api-java-client/issues/detail?id=437