当我从方法返回ResultSet时，它总是关闭的

Question

我有以下类：

public class Refunds {
    ResultSet dataToHash = null;
    public Refunds (String UrnId) {
        Database db = null;
        CallableStatement callable;
        String query = "select * from testmdb.dbo.ApEdiZcusSaSendFile where SourceID='LAN' and UrnID=?";    
        // Get database connection
        try {
            db = new Database("jdbc/refund");
        } catch (NamingException | SQLException e1) {
            e1.printStackTrace();
        }                        
        // Run the query
        try {
            callable = db.connection.prepareCall(query);
            callable.setString(1, UrnId);
            dataToHash = callable.executeQuery();            
        } catch (SQLException s) {
            System.out.println("A SQL exception was thrown while running the query: ");
            s.printStackTrace();
        } catch (Exception e) {
            System.out.println("A general exception was thrown while running the query: ");
            e.printStackTrace();
        } finally {
            db.closeConnection();
        }                
    }
    public ResultSet getDataToHash() {
        return dataToHash;
    }
}

我是这样使用的：

// Get the result set
Refunds refunds = new Refunds(urnId);
ResultSet dataToHash = refunds.getDataToHash();

然而，每一次dataToHash都是.closed()。我没有关闭我的ResultSet。不管问题是什么，我如何修改这个代码，这样当我得到它时，它就不会被关闭？

PS-忽略我的老派System.outs…

Answer 1

关闭连接，从而关闭ResultSet。

与其将ResultSet存储在类成员中，不如将其存储在Refunds内部的局部变量中，并在从Refunds方法返回并关闭连接之前从中读取所有数据。