StringProcessor.java

import java.util.function.Function;

public class StringProcessor {

    private static final Processor<String> processor = new Processor<String>();

    public static void main(String[] args) {
        String command = args[0];  
        lambdaExec(command);
    }

    public static void lambdaExec(String command){
        processor.process(s->exec(s), command);
    }

    public static String lambdaUnrelated(String command){
        return processor.process(s->s+"not related to anything", command);
    }

    public static String exec(String command){
        try {
            command = processor.process(s->s.trim(), command);
            Runtime.getRuntime().exec(command);
            return "Executed: "+command;
        } catch(Exception e) {
            return null;
        }
    } 
}