How to set o real copy of a hashtable inside a array in java?

I'm trying to do a arraylist of a hashtable for that i did:

ArrayList<java.util.Hashtable<Stri开发者_开发技巧ng, String>> info = new ArrayList<java.util.Hashtable<String, String>>();

this did the job but later i needed to add some hashtables inside info using a for cycle:

java.util.Hashtable<String, String> e = new java.util.Hashtable<String, String>();
while(rs.next()){
    e.clear();
    for(String a:dados){
        e.put(a,rs.getString(a));                       
    }
    info.add(e);    
}

The problem is that method add doesnt copy e to info, it only define a pointer to e so when i update e all inserted elements gets the new e values.

Can anyone give some help ?

thx for your time.

This should work:

import java.util.ArrayList;
import java.util.Hashtable;
import java.util.Map;
import java.util.List;

List<Map<String, String>> info = new ArrayList<Map<String, String>>();

while (rs.next()) {
    Map<String, String> e = new Hashtable<String, String>();
    e.clear();
    for (String a : dados) {
        e.put(a, rs.getString(a));
    }
    info.add(e);
}

You should try to avoid declaring collections by their implementation class (declare them as List instead of ArrayList, or Map instead of Hashtable).

Don't need the clear() if you are using new everytime inside the loop.

java.util.Hashtable e = new java.util.Hashtable();

while(rs.next()){ e = new java.util.Hashtable(); for(String a:dados){ e.put(a,rs.getString(a));
} info.add(e);
}