Question

I have this java code which is a part of a managed bean which is used to display data from database into JSF table.

//connect to DB and get customer list
public List<Dashboard> getDashboardList() throws SQLException {

    if (ds == null) {
        throw new SQLException("Can't get data source");
    }

    //get database connection
    Connection con = ds.getConnection();

    if (con == null) {
        throw new SQLException("Can't get database connection");
    }

    PreparedStatement ps = con.prepareStatement(
            "SELECT * from GLOBALSETTINGS");

    //get customer data from database
    ResultSet result = ps.executeQuery();

    List<Dashboard> list = new ArrayList<Dashboard>();

    while (result.next()) {
        Dashboard cust = new Dashboard();

        cust.setUser(result.getString("SessionTTL"));
        cust.setPassword(result.getString("MAXACTIVEUSERS"));


        //store all data into a List
        list.add(cust);
    }
    ps.close();
    con.close();
    return list;        
}

I want to improve this code and insert try catch statements. What is the proper way to do this?

Answer 1

how to improve this code with try-catch exeptions?

You can review your question title, since you are not asking about improvement, but maybe organizing. Based on your code, I changed your method so that it looks cleaner and more organized about catching exceptions.

public List<Dashboard> getDashboardList(DataSource ds)
{   
    List<Dashboard> list = new ArrayList<Dashboard>();
    Connection con = null;
    PreparedStatement ps = null;
    try
    {
        con = ds.getConnection();
        ps = con.prepareStatement("SELECT * from GLOBALSETTINGS");
        //get customer data from database
        ResultSet result = ps.executeQuery();
        while (result.next())
        {
            Dashboard cust = new Dashboard();
            cust.setUser(result.getString("SessionTTL"));
            cust.setPassword(result.getString("MAXACTIVEUSERS"));
            list.add(cust);
        }
    }
    catch(Exception e1)
    {
        // Log the exception.
    }
    finally
    {
        try
        {
             if(ps != null)
                  ps.close();
             if(con != null)
                  con.close();
        }
        catch(Exception e2)
        {
            // Log the exception.
        }
    }
    return list; 
}