Who can analyze this class ,does it will cause a problem?

Question

package db;
import java.sql.*;
import javax.naming.Context;
import javax.naming.InitialContext;
import javax.sql.DataSource;
public class DbManager
private static Context jdbcContext;
public static Connection getConnect(String dataSource)
throws ClassNotFoundException, SQLException
String s;
Connection conn=null;
if (dataSource==null)
s= "jdbc/hoss";
else
s=dataSource;
if(jdbcContext == null)
try
jdbcContext = new InitialContext();
catch(Exception exception)
System.out.println(exception);
try
conn = ((DataSource)jdbcContext.lookup(s)).getConnection();
catch(Exception exception1)
System.out.println(exception1);
return conn;
public static ResultSet execQuery(String s,Connection conn)
throws SQLException
Statement statement = conn.createStatement();
ResultSet resultset = statement.executeQuery(s);
     //statement.close();
return resultset;
public static ResultSet execQuery(String s,Connection conn,Statement statement)
     throws SQLException
     ResultSet resultset = statement.executeQuery(s);
     return resultset;
public static int execUpdate(String s,Connection conn)
throws SQLException
Statement statement = conn.createStatement();
int i = statement.executeUpdate(s);
     statement.close();
return i;
this is a class writed by me ,but now i have some problem with it
all the problems is focus on the following method:
public static ResultSet execQuery(String s,Connection conn)
throws SQLException
Statement statement = conn.createStatement();
ResultSet resultset = statement.executeQuery(s);
     //statement.close();
return resultset;
if the statement is closed ,the resultset will automatically be close;
if you don't close statement here i have two wonder:
1)after the method return the statement is local variable,it will died
and the resultset will can also do thing?
2)whether it will lock the database after long run

Answer 1

If you don't close the ResultSet and the Statement, I think you may have an SQLException sooner or later, telling you there are no more cursors left.