# Using KoLDfish-dam in Java
## Setup
We are using [Apache Maven](http://maven.apache.org) to build koldfish-dam.
The system has been tested under Linux, but should work with other os aswell.
To use it, do the following:
1. Download the source code via github.
2. Execute the following command on your command line: `mvn install`
3. Include the following dependecy to your own maven project.
  ```xml
  <dependency>
    <!-- Maven Data Acquisition Module-->
    <groupId>de.unikoblenz.west.koldfish</groupId>
    <artifactId>koldfish-dam</artifactId>
    <version>alpha1</version>
  </dependency>
  ```

## The Java API
The concept of dam is completely message driven.
Messages are sent between all components to realise
The API consists of the following interfaces:
- Negotiator:
  is responsible to access the LOD cloud by
- Controller:
  requests an action, e.g. do dereference an URI, from a Negotiator and receives the answer.
- Accessor: gets activated by a Negotiator to answer a request and sends the answer back.
- Receiver: listenes to a Negotiator and gets notified if an Accessor returns an answer.

The communication between Controller - Negotiator - Accessor uses futures and the communicaton between Negotiator and Receiver is listener pattern based.