public static ArrayList<Centro> centros_search;

centros_search= new ArrayList<Centro>();


        String myDriver = "com.mysql.jdbc.Driver";
        String myUrl = "jdbc:mysql://[IP]:3306/";
        Connection conn = null;
        try {
            Class.forName(myDriver);
            conn = DriverManager.getConnection(myUrl, "user", "password");
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        } catch (SQLException e) {
            e.printStackTrace();
        }


        String sql = "SELECT * FROM `Centro`";

        // create the java statement

        Statement stmt = null;
        ResultSet rs = null;
        try {
            stmt = conn.createStatement();
            rs = stmt.executeQuery(sql);


            //STEP 5: Extract data from result set
            while(rs.next()){
                //Retrieve by column name
                String id  = rs.getString("centreID");
                String name = rs.getString("centreName");
                String dir = rs.getString("centreDir");
                String number = rs.getString("centreNumber");


               //System.out.println(id+"----"+name+"----"+dir+"----"+number);
               Centro c = new Centro(id,name,dir,number);
               centros_search.add(c);

            }

            rs.close();
            conn.close();
            stmt.close();

        } catch (SQLException e) {
            e.printStackTrace();
        }


            doThat();
    }

for (Centro c: centros_search){
     System.out.println(c.centreID+"----"+c.centreName+"----"+c.centreDir+"----"+c.centreNumber);

}

//UI ELEMENTS
private static RecyclerView rv;
static LinearLayoutManager llm;
Button b1;
public static ArrayList<Centro> centros_search;
static RVAdapter adapter;


Centro c;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_searchable);


    centros_search = new ArrayList<Centro>();
    rv = (RecyclerView)findViewById(R.id.rvSearch);

    llm = new LinearLayoutManager(this.getApplicationContext());

    Centro c = new Centro("lol","lols","cccccc","176378238");
    centros_search.add(c);





    b1 = (Button) findViewById(R.id.button_search);
    b1.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            do_search();
        }
    });
}

private static void do_search() {

    centros_search.clear();
    Centro c1 = new Centro("lol2","lol2","cccccc","176378238");
    centros_search.add(c1);

    try {
    String myDriver = "com.mysql.jdbc.Driver";
    String myUrl = "jdbc:mysql://[IP]:3306/meapuntoapp";
    Connection conn = DriverManager.getConnection(myUrl, "user", "password");
    Class.forName(myDriver);



    String sql = "SELECT * FROM `Centro`";

    // create the java statement

    Statement stmt = null;
    ResultSet rs = null;


        stmt = conn.createStatement();
        rs = stmt.executeQuery(sql);


        //STEP 5: Extract data from result set
        while(rs.next()){
            //Retrieve by column name
            String id  = rs.getString("centreID");
            String name = rs.getString("centreName");
            String dir = rs.getString("centreDir");
            String number = rs.getString("centreNumber");


            System.out.println(id+"----"+name+"----"+dir+"----"+number);
            Centro c = new Centro(id,name,dir,number);
            centros_search.add(0,c);
            nonSense(c);
        }

        rs.close();
        conn.close();
        stmt.close();





    } catch (SQLException e) {
        e.printStackTrace();
    } catch (ClassNotFoundException e) {
        e.printStackTrace();
    }



    Centro c3 = new Centro("lol2","lol3","cccccc","176378238");
    centros_search.add(c3);
    adapter = new RVAdapter(centros_search);
    rv.setAdapter(adapter);
    rv.setLayoutManager(llm);

}

 private static void nonSense(Centro c) {

    centros_search.add(c);

}