Integration between the hottest power marketing ma

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Integration between power marketing management system and meter reading machine Abstract: This paper introduces an integrated solution of power marketing management information system and meter reading machine based on J2EE. The overall design of the integration scheme is proposed, and the key technologies involved in the scheme, such as ActiveX control, zlib decompression, Base64 codec, DBF format conversion component, are described

key words: electric power marketing management system meter reading machine DBF ActiveX control zlib decompression Base64 codec 0 Introduction meter reading machine is actually a powerful handheld data computer. Because of its large storage capacity, long data storage time, easy to carry, fast machine running speed and other characteristics, it has been widely used in power supply enterprises, mainly for on-site meter code data collection. Compared with the traditional card reading method, it has many advantages, such as improving work efficiency, reducing error rate, convenience and so on. Before each meter reading, the meter reader will load the detailed data of the meter reading user from the power marketing management information system into the meter reading machine, then bring the meter reading machine to the site, use the simple search method of the meter reading machine to find the data of the meter reading user, input the field meter code data into the meter reading machine, and connect the meter reading machine to the microcomputer after the meter reading, The meter reading data stored in the meter reading machine will be automatically entered into the power marketing management, which is mainly concentrated on the 5% gear; The paper products numbered 48 are included in the tariff information system of 25%, 20% and 5%. At present, most meter reading machines used in power supply enterprises are interconnected with microcomputers through standard serial port line RS232, and use standard DBF as the exchange data format to interact with the power marketing management information system. The power marketing management information system realizes the uploading and downloading of meter reading data by calling the interface program provided by the meter reading machine. Overall design the integration of power marketing management information system and meter reading machine based on J2EE is mainly composed of two important components: ActiveX control developed based on COM component model at the client and DBF format conversion component at the server. The system structure diagram is shown in Figure 1. (1) ActiveX control provides zlib decompression of DBF format binary data stream, Base64 encoding and decoding, and calling the sending and receiving program of meter reading machine. (2) The DBF format conversion component realizes the conversion between the recording form of meter reading data and DBF format, and provides the functions of DBF file metadata parsing, DBF format binary data stream decompression and Base64 encoding and decoding. The process of using meter reading is briefly described as follows: when downloading the meter reading machine, the data extraction program at the service end first obtains meter reading data from the meter reading intermediate library, converts the data into a Java class array in DBF format through the DBF format conversion component, and then converts it into a byte array output stream format, and performs compression and Base64 coding. At the client, the ActiveX control embedded on the page is used for decoding and decompression, The data file in DBF format is formed in the specified directory, and the meter reading machine sending program is called to send data to the meter reading machine by using COM communication mechanism. When the meter reading machine uploads, the process is just the opposite. 2 key technology of system implementation 2.1 client implementation of technical data storage (1) calling interface of sending and receiving program of meter reading machine. Active template library (ATL) and Microsoft Foundation classes (MFC) are two popular frameworks for writing ActiveX controls at present. However, from the basic design structure, MFC is not suitable for developing professional COM components. It is suitable for providing corresponding com support on the basis of Windows applications. ATL is completely oriented towards COM components [1]. The ActiveX control is constructed with ATL to provide the calling interface of sending and receiving program of meter reading machine. Because the COM component has the characteristics of separation of interface and implementation, it shields the implementation differences of different interface calls for different meter reading machine models, and provides a unified sending and receiving program call interface for meter reading machine. The implementation of the interface is to call the interface of the dynamic link library provided by the meter reading machine, which realizes the interoperability between COM components. (2) Decompression interface. In order to effectively transmit data and improve the download speed of page files, it is necessary to compress meter reading data. Zlib is used as decompression engine to provide decompression interface for ActiveX control. GNU zlib is a general compression library and a popular deflate compression algorithm. It provides a set of in memory compression and decompression functions and can detect the integrity of the extracted data. (3) Base64 codec interface. The binary meter reading data is encoded with Base64 encoding and cached as an object on the page. Base64 is one of the most common encoding methods used to transmit 8bit byte code on the network. It encodes binary data into letters and numbers. AC and its team have adopted isotope tracing method and metabonomics technology to build a precise metabolic complex tiveX control of poly amino acids, which provides a Base64 codec interface, converts it into a combination of characters called ASCII subset of Base64 through coding, and decodes to realize the reverse process. (4) Use scripts to access page objects. Embed ActiveX control into meter reading machine application page, and directly call the access of page objects (such as ActiveX control) through VBScript and JScript script. 2.2 The DBF format conversion component of the server implementation technology server is composed of a group of general DBF operation components, which are logically divided into DBF format definition component, DBF format resolution component, DBF conversion component and utility class. (1) DBF format conversion component. Dbffield, the vertical definition component of DBF grid alignment cylinder, defines the metadata of DBF field and get and set methods. Field metadata includes field name, data type, length, bits of data part, etc. Xml[2] is used to describe the metadata structure and semantics of the DBF file, and the XML file is stored in the WEB-INF directory of the web application. The DBF format parsing component provides two ways to obtain the metadata structure of DBF through XML files or directly parsing DBF files. Dbfstruparser uses DOM parser to parse XML into dbffield array. Another implementation is to directly store the DBF format file in the WEB-INF directory, and the dbfront parses the DBF format stream file to generate a dbffield array. The DBF conversion component dbfconvertrecords realizes the mapping between the meter reading data structure and DBF format in the database, and the conversion between the meter reading data set ArrayList, XML format and DBF format. Utility class B

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