import java.sql.* ;
import javax.servlet.http.* ;

public class ConnectionBean implements HttpSessionBindingListener {
 public Connection conn;
 private Statement stmt;
 private String dbURL=
 "jdbc:oracle:thin:scott/tiger@machine1:1521:db";
public ConnectionBean() {
try {
  DriverManager.registerDriver(new oracle.jdbc.driver.OracleDriver());
 conn = DriverManager.getConnection(dbURL);
 statement = conn.createStatement();
}
catch (SQLException e) {
 System.err.println("ConnectionBean: driver not loaded: " + e);
conn=null;
 }
} /// ConnectionBeanconstructor

public void setDbURL (String d) {
 dbURL = d;
} ///setDbURL

public Connection getConnection() {
 return conn;
} /// getConnection

public void commit() throws SQLException {
 conn.commit();
}

public void rollback() throws SQLException {
 conn.rollback();
} ///rollback

public void setAutoCommit (boolean autoCommit) throws SQLException {
 conn.setAutoCommit(autoCommit);
} ///setAutoCommit

public ResultSet executeQuery(String sql) throws SQLException {
 return stmt.executeQuery(sql);
} /// executeQuery

public int  executeUpdate(String sql) throws SQLException {
  return stmt.executeUpdate(sql);
} /// executeUpdate

public CallableStatement prepareCall (String sql) throws SQLException {
 return conn.prepareCall(sql);
} ///prepareCall

public void valueBound(HttpSessionBindingEvent event) {
 try {
 if (conn == null || conn.isClosed()) {
 conn = DriverManager.getConnection(dbURL);
  stmt = conn.createStatement();
 } /// if conn == null
}  catch (SQLException e) {
System.err.println("ConnectionBean: in the valueBound method");
conn= null;
}
} ///valueBound

public void  valueUnbound(HttpSessionBindingEvent event) {
  try {
  conn.close();
}
catch (SQLException e) {
}
finally {
conn=null;
  }
} ///valueUnbound

protected void finalize() {
 try {
  conn.close();
}
 catch (SQLException e) {
}
} /// finalize
} /// ConnectionBean