打开和关闭不同类的连接 [英] Opening and closing connection on different class

问题描述

是否可以将代码分成3部分。我是指3个不同的文件。第一部分用于连接SQL服务器，第二部分用于操作数据库，第三部分用于关闭连接。代码只是一个例子。

Is it possible to separate the code into 3 part. I mean 3 different file. First part for connecting to SQL server, second part for manipulating database and third part is for closing the connection. The code is just an example.

/**
 * CloseConnection.java
 * Copyright (c) 2007 by Dr. Herong Yang. All rights reserved.
 */
import java.sql.*;
public class CloseConnection {
  public static void main(String [] args) {
    Connection con = null;
    try {

// Load Microsoft JDBC Driver 1.0
      Class.forName(
        "com.microsoft.sqlserver.jdbc.SQLServerDriver");

// Obtaining a connection to SQL Server
      con = DriverManager.getConnection(
          "jdbc:sqlserver://localhost:1269;"
        + "user=sa;password=HerongYang");

// Connection is ready to use
      DatabaseMetaData meta = con.getMetaData();
      System.out.println("Server name: " 
        + meta.getDatabaseProductName());
      System.out.println("Server version: "
        + meta.getDatabaseProductVersion());

// Closing the connection
      con.close();
      if (con.isClosed()) 
        System.out.println("Connection closed.");

    } catch (java.lang.ClassNotFoundException e) {
      System.err.println("ClassNotFoundException: "
        +e.getMessage());
    } catch (SQLException e) {
      System.err.println("SQLException: "
        +e.getMessage());
    }
  }
}

推荐答案

扩展基类，它提供的东西是所有3个部分共享（编辑：像连接conn）

但是为什么要拆分？对我来说看起来很好。

Extend a base class, which provides the stuff that is shared by all 3 parts ( like the Connection "conn")
But why split that? Looks fine to me like it is.

在java中，将源代码拆分到不同文件中的唯一方法是代码是否存在于不同的类中。您可以编写具有在派生类（或类）中扩展的特定行为的基类。

In java, the only way to split source code in different files is if the code exists in different classes. You can write a base class with certain behavior that is extended in a derived class (or classes).

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