Access a method for a DB connection. HELP URGENT thnx

Question

Hi I am trying to create a method in another class to call another method that checks for userid in DB? What is the best way to set this up? I.e. calling method?
//calling method below line
private boolean setuserExist(String username) {
     else return false;
public String getserExist() {
          return userexist;
// Method being called below this line
public boolean userExist(String username){
          boolean exist = false;
          System.out.println("in LoginDBAccess: username is " + username);
          try{
Connection conn = dbc.getConnection();
Statement statement = conn.createStatement();
String query =      "SELECT User.UserID " +
                    "FROM User " +
                    "WHERE User.UserID = '" + username + "'";
ResultSet resultSet = statement.executeQuery(query);
System.out.println("1.1");
ArrayList result = new ArrayList();
while(resultSet.next()){
     //System.out.println("In While:");
ArrayList item = new ArrayList();
item.add(resultSet.getString("UserID"));
result.add(item);
System.out.println("LoginDBAccess Count: " + result.size());
conn.close();
if (result.size() == 1){
     exist = true;
          }catch(Exception e){
     e.printStackTrace();
          return exist;
     }

Answer 1

The better question is I guess,
How do I use this code below to call the 2nd block of code or method?
private boolean setuserExist(String username) {
else return false;
public String getserExist() {
return userexist;
}// 2nd Method being called below this line
public boolean userExist(String username){
boolean exist = false;
System.out.println("in DB: username is " + username);
try{
Connection conn = dbc.getConnection();
Statement statement = conn.createStatement();
String query = "SELECT User.UserID " +
"FROM User " +
"WHERE User.UserID = '" + username + "'";
ResultSet resultSet = statement.executeQuery(query);
System.out.println("1.1");
ArrayList result = new ArrayList();
while(resultSet.next()){
ArrayList item = new ArrayList();
item.add(resultSet.getString("UserID"));
result.add(item);
System.out.println("DB Count: " + result.size());
conn.close();
if (result.size() == 1){
exist = true;
}catch(Exception e){
e.printStackTrace();
return exist;
}