SimpleDataBox

package my.util;

import java.util.ArrayList;

public interface DataBox {

public int on(String type, Object value);

public void off(String type, Object value);

public void off(String type, int index);

public void off(String type);

public void off();

public void trigger(String type);

public void trigger(String type, Object value);

public ArrayList<Object> get(String type);

public Object get(String type, Object value);

}

package my.util;

import java.util.ArrayList;

import java.util.HashMap;

public class SimpleDataBox implements DataBox{

protected HashMap<String, ArrayList<Object>> index = new HashMap<>();

@Override

public int on(String type, Object value) {

if(!index.containsKey(type)){

index.put(type, new ArrayList<Object>());

}

index.get(type).add(value);

return index.get(type).size();

}

@Override

public void off(String type, Object value) {

if(!index.containsKey(type)) return;

if(index.get(type).isEmpty()) return;

if(!index.get(type).contains(value)) return;

index.get(type).remove(value);

}

@Override

public void off(String type, int index) {

if(!this.index.containsKey(type)) return;

if(this.index.get(type).isEmpty()) return;

if(index >= this.index.get(type).size()) return;

this.index.get(type).remove(index);

}

@Override

public void off(String type) {

if(!index.containsKey(type)) return;

if(index.get(type).isEmpty()) return;

index.get(type).clear();

}

@Override

public void off() {

index.clear();

}

@Override

public void trigger(String type) {

if(!index.containsKey(type)) return;

for(int i=0, l=index.get(type).size(); i<l; ++i){

System.out.println(index.get(type).get(i).toString());

}

}

@Override

public void trigger(String type, Object value) {

if(!index.containsKey(type)) return;

if(!index.get(type).contains(value)) return;

System.out.println(value);

}

@Override

public ArrayList<Object> get(String type) {

return index.get(type);

}

@Override

public Object get(String type, Object value) {

if(!index.containsKey(type)) return null;

if(!index.get(type).contains(value)) return null;

return value;

}

}