Java Web Service (Restlet) Project - Add new features, modify existing

Need to enhance existing project and add more features. Framework is already implemented. Need to build new classes and modify existing. New classes must follow the existing framework and available utilities. Database tables already built.
Tools/Technology:
• JDK 1.6
• Java Web Service using Restlet RESTful web framework
• Spring Hibernate
• MySQL
• Tomcat 5.5
• Eclipse
• XML

Use Cases (only server side implementation)
1. LinkedIn API: Client will send linkedin token after authorization. Service will use the token, calls the linkedin api, fetch user details and save in database. Framework to use linkedin api is already in place. The requirement is to parse the data and save in database. Each record may have 25-30 fields
2. Facebook API: Client will send facebook user/password. Service will call the Facebook graph api, fetch user details and save in database. Framework to use facebook api is already in place. The requirement is to parse the data and save in database. Each record may have 25-30 fields.

3. XML contact processing: Client will send list of records in a proper xml format. Service should parse the xml and save each record in the database. Each record may have 10-15 fields.
4. Merge API: Service should implement a servlet which will read 4 different tables, iterate each record, check some pre-defined rules and update a master table. There will be approx 30-35 simple rules to match (basically if-else statements).
5. Get simple lists: Service should return some processed data in xml format to client. There will be 5 lists. Processing logic will be provided. All lists should be implemented by single service. Client will send input parameters which will be used by the service to process the data and return the lists.
6. Save log: client will send data in xml format. Service will parse the xml and save the data in database. The xml may have multiple records.

Service will be integrated with our existing client side code. There may be integration related issues (server side only) which should be fixed by the developer.