COBOL 语言 代理模式远程访问示例

COBOL阿木 发布于 2025-06-15 20 次阅读


阿木博主一句话概括:COBOL 语言代理模式在远程访问中的应用与实践

阿木博主为你简单介绍:
随着信息技术的不断发展,企业对系统间数据交换和远程访问的需求日益增长。COBOL(Common Business-Oriented Language)作为一种历史悠久、应用广泛的商业编程语言,在许多企业中仍然扮演着重要角色。本文将探讨COBOL语言中代理模式的应用,通过一个远程访问的示例,展示如何使用代理模式实现不同系统间的数据交互。

关键词:COBOL;代理模式;远程访问;数据交互

一、

COBOL语言因其稳定性和可靠性,在金融、保险、政府等领域有着广泛的应用。随着新技术的不断涌现,如何让COBOL系统与新兴技术无缝对接,成为了一个亟待解决的问题。代理模式作为一种设计模式,可以有效地实现远程访问和数据交互。本文将围绕COBOL语言代理模式远程访问示例,展开详细的技术探讨。

二、COBOL语言代理模式概述

代理模式是一种结构型设计模式,其主要目的是为其他对象提供一种代理以控制对这个对象的访问。在COBOL语言中,代理模式可以通过以下步骤实现:

1. 定义一个接口,用于定义代理和真实对象共有的操作。
2. 创建一个代理类,实现接口,并在内部维护一个真实对象的引用。
3. 在代理类中,实现接口中的方法,根据需要调用真实对象的方法。
4. 在客户端,通过代理类来访问真实对象,而不直接与真实对象交互。

三、COBOL语言代理模式远程访问示例

以下是一个简单的COBOL语言代理模式远程访问示例,假设我们需要从远程数据库中获取数据,并将其显示在本地终端。

1. 定义接口

cobol
IDENTIFICATION DIVISION.
PROGRAM-ID. DATA-ACCESS-INTERFACE.

INTERFACE SECTION.
PROCEDURE DIVISION USING DATA-ACCESS-INTERFACE-INFO.
PERFORM GET-DATA-FROM-REMOTE-SYSTEM
PERFORM DISPLAY-DATA-ON-LOCAL-TERMINAL.
END-PRECEDURE.
END-INTERFACE.

2. 创建代理类

cobol
IDENTIFICATION DIVISION.
PROGRAM-ID. DATA-ACCESS-AGENT.

CLASS DATA-ACCESS-AGENT DEFINED BY DATA-ACCESS-AGENT-INFO.
DATA DIVISION.
FD DATA-ACCESS-AGENT-INFO.
01 ACCESS-INFO.
05 DATABASE-NAME PIC X(30).
05 USER-ID PIC X(20).
05 PASSWORD PIC X(20).
05 QUERY PIC X(100).
END-CLASS.

OBJECT DATA-ACCESS-AGENT-INSTANCE TYPE DATA-ACCESS-AGENT.
DATA DIVISION.
FD DATA-ACCESS-AGENT-INSTANCE.
01 ACCESS-INSTANCE.
05 DATABASE-NAME PIC X(30).
05 USER-ID PIC X(20).
05 PASSWORD PIC X(20).
05 QUERY PIC X(100).
END-CLASS.

PROCEDURE DIVISION.
PERFORM INITIALIZE-AGENT
PERFORM EXECUTE-INTERFACE
PERFORM TERMINATE-AGENT.
END-PRECEDURE.

INITIALIZE-AGENT.
PERFORM SET-ACCESS-INFO.
END-PRECEDURE.

SET-ACCESS-INFO.
MOVE 'REMOTE_DATABASE' TO DATABASE-NAME.
MOVE 'USER' TO USER-ID.
MOVE 'PASSWORD' TO PASSWORD.
MOVE 'SELECT FROM TABLE' TO QUERY.
END-PRECEDURE.

EXECUTE-INTERFACE.
PERFORM CALL-REAL-OBJECT.
END-PRECEDURE.

CALL-REAL-OBJECT.
PERFORM REAL-OBJECT-PROCEDURE.
END-PRECEDURE.

REAL-OBJECT-PROCEDURE.
PERFORM REAL-OBJECT-INTERFACE.
END-PRECEDURE.

REAL-OBJECT-INTERFACE.
PERFORM REAL-OBJECT-PROCEDURE.
END-PRECEDURE.

TERMINATE-AGENT.
EXIT PROCEDURE.
END-PRECEDURE.

3. 实现真实对象

cobol
IDENTIFICATION DIVISION.
PROGRAM-ID. REAL-OBJECT.

CLASS REAL-OBJECT DEFINED BY REAL-OBJECT-INFO.
DATA DIVISION.
FD REAL-OBJECT-INFO.
01 REAL-INFO.
05 DATABASE-NAME PIC X(30).
05 USER-ID PIC X(20).
05 PASSWORD PIC X(20).
05 QUERY PIC X(100).
END-CLASS.

OBJECT REAL-OBJECT-INSTANCE TYPE REAL-OBJECT.
DATA DIVISION.
FD REAL-OBJECT-INSTANCE.
01 REAL-INSTANCE.
05 DATABASE-NAME PIC X(30).
05 USER-ID PIC X(20).
05 PASSWORD PIC X(20).
05 QUERY PIC X(100).
END-CLASS.

PROCEDURE DIVISION.
PERFORM INITIALIZE-REAL-OBJECT
PERFORM EXECUTE-REAL-OBJECT
PERFORM TERMINATE-REAL-OBJECT.
END-PRECEDURE.

INITIALIZE-REAL-OBJECT.
PERFORM SET-REAL-INFO.
END-PRECEDURE.

SET-REAL-INFO.
MOVE 'REMOTE_DATABASE' TO DATABASE-NAME.
MOVE 'USER' TO USER-ID.
MOVE 'PASSWORD' TO PASSWORD.
MOVE 'SELECT FROM TABLE' TO QUERY.
END-PRECEDURE.

EXECUTE-REAL-OBJECT.
PERFORM REAL-OBJECT-PROCEDURE.
END-PRECEDURE.

REAL-OBJECT-PROCEDURE.
PERFORM REAL-OBJECT-INTERFACE.
END-PRECEDURE.

REAL-OBJECT-INTERFACE.
PERFORM REAL-OBJECT-PROCEDURE.
END-PRECEDURE.

TERMINATE-REAL-OBJECT.
EXIT PROCEDURE.
END-PRECEDURE.

4. 客户端调用代理

cobol
IDENTIFICATION DIVISION.
PROGRAM-ID. CLIENT-PROGRAM.

ENVIRONMENT DIVISION.
CONFIGURATION SECTION.
SOURCE-COMPUTER. IBM-370.
OBJECT-COMPUTER. IBM-370.

DATA DIVISION.
FILE SECTION.
FD DATA-ACCESS-AGENT-INSTANCE.
01 ACCESS-INSTANCE.
05 DATABASE-NAME PIC X(30).
05 USER-ID PIC X(20).
05 PASSWORD PIC X(20).
05 QUERY PIC X(100).

WORKING-STORAGE SECTION.
01 WS-ACCESS-INSTANCE.
05 WS-DATABASE-NAME PIC X(30).
05 WS-USER-ID PIC X(20).
05 WS-PASSWORD PIC X(20).
05 WS-QUERY PIC X(100).

PROCEDURE DIVISION.
PERFORM INITIALIZE-CLIENT
PERFORM CALL-AGENT
PERFORM TERMINATE-CLIENT.
END-PRECEDURE.

INITIALIZE-CLIENT.
PERFORM SET-ACCESS-INSTANCE.
END-PRECEDURE.

SET-ACCESS-INSTANCE.
MOVE 'REMOTE_DATABASE' TO WS-DATABASE-NAME.
MOVE 'USER' TO WS-USER-ID.
MOVE 'PASSWORD' TO WS-PASSWORD.
MOVE 'SELECT FROM TABLE' TO WS-QUERY.
END-PRECEDURE.

CALL-AGENT.
PERFORM CALL-REAL-OBJECT.
END-PRECEDURE.

CALL-REAL-OBJECT.
PERFORM REAL-OBJECT-INTERFACE.
END-PRECEDURE.

REAL-OBJECT-INTERFACE.
PERFORM REAL-OBJECT-PROCEDURE.
END-PRECEDURE.

TERMINATE-CLIENT.
EXIT PROCEDURE.
END-PRECEDURE.

四、总结

本文通过一个COBOL语言代理模式远程访问示例,展示了如何使用代理模式实现不同系统间的数据交互。代理模式在COBOL语言中的应用,不仅能够提高代码的可维护性和可扩展性,还能够使COBOL系统更好地适应新技术的发展。随着企业对系统间数据交换和远程访问需求的不断增长,COBOL语言代理模式的应用将越来越广泛。

(注:以上代码仅为示例,实际应用中需要根据具体情况进行调整。)