Right way to make my own collection in java -

i'm trying own collection class in java.

i need find data key , able iterate on , element index, decide make encapsulation of hashtable , arraylist.

this code:

public class geocollection <t extends geographic> implements iterable<t>, iterator<t>{  private hashtable<string,t> data_table; private arraylist<t> data; private int cursor = 0;  public geocollection(){     data = new arraylist<>();     data_table = new hashtable<>(); }  public void add(string key,t data){     this.data.add(data);     data_table.put(key,data); }  public t get(int index){     if(index >= data.size())         throw  new indexoutofboundsexception();     return data.get(index); }  public t get(string v){     return data_table.get(v); }  public t next() {     if( cursor == data.size())         throw new nosuchelementexception();     cursor++;     return data.get(cursor-1); }  public t first(){     cursor = 0;     return data.get(cursor); } public boolean hasnext(){     return cursor < data.size(); }  public boolean remove(person p) {     return data.remove(p); }  //se implemeta el iterator @override public iterator<t> iterator() {     cursor = 0;     return this; } 

}

there's need implement list interface or that? because don't know if encapsulating hashtable , arraylist , implementing basic operations in enough call "collection" class.

i thankful advice or correction of code.

thanks.

i think best way implementing collection

implements java.util.collection<e> 

that way have implement every method in collection interface bt making class extending abstractcollection extends abstractcollection more easy since nessessary things , thing have worry iterator() , size()