Java Filter For Logstash

You know how there is a ruby filter for Logstash which enables me to write code in Ruby and it is usually included in the config file as follows

```
filter {
ruby {
code => "...."
}
}
```

Now I have two Jar files that I would like to include in my filter so that the input I have can be processed according to the operations I have in these Jar files. However, I cannot (apparently) include the Jar file in the ruby code. I've been looking for a solution. Any help?