scribe-java-bitbucket
These classes makes it possible to use Bitbucket API from Scribe, like this.
OAuthService service = new ServiceBuilder()
                                  .provider(BitbucketApi20.class)
                                  .apiKey(BITBUCKET_API_KEY)
                                  .apiSecret(BITBUCKET_API_SECRET)
                                  .build(); 
See the documentation for Scribe for more usage instructions.
The project is available from Maven Central:
<dependency>
    <groupId>se.mnord.scribe</groupId>
    <artifactId>scribe-java-bitbucket</artifactId>
    <version>1.0.0</version>
</dependency>