java - 遵循哪种设计模式使代码结构化

Question

我创建了一个名为“DownloadManagerWrapper 的类，它将根据运行时参数调用。我可以遵循以下代码的任何设计模式以使其干净和结构化吗？如果可能的话我可以选择哪种设计模式? 如果可能的话，需要您的建议和示例设计模式代码以及简单的解释，因为我是设计模式的新手。

public class DownloadManagerWrapper {

    public static void main(String[] args) {
    String downloadId = args[0];
    String bankId =args[1];
    String serviceId =args[2];
    readInterfaceConfig(serviceId,bankId,downloadId);
    }

    public static void readInterfaceConfig(String intfCode,String bankId,String downloadId) {

    Connection conn = CRMConnection.getConnection();

    String statusOfDownload;
    DownloadManager dwlManager = new DownloadManager();

    ResultSet rs=null;

    if(downloadId.equals("A"))
    {
    if(intfCode.equals("-1")) //all download
    {
        String query = "select INTF_CODE from CRMUSER.TABLE1 where bank_id ="+"'"+bankId+"'"+"order by INTF_CODE";
        System.out.println("query>"+query);
        try
        {
        Statement st = conn.createStatement();
        rs = st.executeQuery(query);
                while(rs.next())
             {
                    String intfCodeFromDB = rs.getString("INTF_CODE");
                    statusOfDownload = new DownloadManager().downloadDataFromCore(intfCodeFromDB,bankId,downloadId);
             }
        }
        catch(SQLException e)
        {
        e.printStackTrace();
        }
        finally
        {
        try {
            rs.close();
        } catch (SQLException e) {
            e.printStackTrace();
        }
        }
    }
    else  //specific download
    {
          statusOfDownload = dwlManager.downloadDataFromCore(intfCode,bankId,downloadId);
    }
    }
    else if(downloadId.equals("I"))
    {
           if(intfCode.equals("-1")) //all download
        {
            String query = "select INTF_CODE from CRMUSER.TABLE1 where bank_id ="+"'"+bankId+"'"+"order by INTF_CODE";
            System.out.println("query>"+query);
            try
            {
            Statement st = conn.createStatement();
            rs = st.executeQuery(query);
                    while(rs.next())
                 {
                        String intfCodeFromDB = rs.getString("INTF_CODE");
                        statusOfDownload = new DownloadManager().downloadDataFromCore(intfCodeFromDB,bankId,downloadId);
                 }
            }
            catch(SQLException e)
            {
            e.printStackTrace();
            }
            finally
            {
            try {
                rs.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
            }
        }
        else  //specific download
        {
              statusOfDownload = dwlManager.downloadDataFromCore(intfCode,bankId,downloadId);
        }
    }
    }
}

Answer 1

一些提示:

• 访问数据库应该通过 Data Access Object (道)模式

• 如果你有很多 if 语句，你应该看看 Strategy Pattern .