CN102254334B - Method for sharing service of map symbolization network based on DCOM (distributing component object model) technology - Google Patents

Abstract

The invention relates to a map symbolization network sharing service method, in particular to a map symbolization network sharing service method based on DCOM technology. The main steps include the client requesting the symbol library object from the server; the server creating the symbol library object; the server importing the remote symbol library; the client setting the drawing scale; The client performs symbolization and marshals the symbolization result back to the client; the client draws and displays the symbolization result. The invention provides a computerized map-drawing scheme with concise model, high configuration efficiency, which can complete map symbolization sharing service on local area network, wide area network and Internet, and realize map symbol and map symbolization service sharing.

Description

A method of map symbolization network sharing service based on DCOM technology

technical field

The invention relates to a map symbolization network sharing service method, in particular to a map symbolization network sharing service method based on DCOM technology.

Background technique

Symbols are the basic elements of maps, and the study of symbols is one of the basic problems of cartography. As a map language, map symbols have two functions of reading and writing: "reading" means that the map user can recognize the cartographic space through the identification of symbols; shown on the map. Map symbols and map symbol libraries are one of the core issues of geographic information systems and various cartographic software. However, due to the large differences in data structures, symbol models, and drawing methods among different systems and cartographic software, each system or It is difficult to complete the sharing of map symbols between mapping software.

Aiming at the problem of map symbol sharing, some related patents have appeared, such as: "Path-based point map symbol model and sharing method based on the model" (application number: 201019026032.8), "Path-based linear map symbol model and Sharing method based on this model" (application number: 201019026030.9), "Path-based area map symbol model and sharing method based on this model" (application number: 201019026029.6), the above three invention patents proposed a path-based Map symbol model, and proposed a method for sharing map symbols based on the path model; "AutoCAD block and path-based point map symbol exchange method" (application number: 201019026028.1), "TrueType symbols and path-based point map symbols Exchange Method" (Application No.: 201019026034.7), "Exchange Method for Point Symbols Based on Primitive Method and Point Map Symbols Based on Path" (Application No.: 201019026026.2), the above three patents are based on the path-based point symbol model, Proposes the transformation methods of AutoCAD blocks, TrueType symbols, and primitive point symbols in three different formats to path-based point symbols; "VGE symbol model and map symbol sharing system and method based on the model" (application No.: 201019026033.2), proposed a symbol model based on VGE and a map symbol sharing method based on the model. The relevant patents mentioned above all propose one or several map symbol models, and then elaborate their related symbol sharing methods on the basis of the proposed symbol models. It is necessary to convert symbol models in other formats into their proposed symbols Model.

Contents of the invention

The present invention mainly solves the problem existing in the prior art that it is difficult to complete the sharing of map symbols between various systems or mapping software due to the large differences in data structures, symbol models, and drawing methods among different systems and mapping software. and other technical issues; provide a client that can freely choose the symbolic server to reasonably achieve load balancing between the network and the symbolic server; the symbol library server can be located at the symbolic server or distributed A DCOM technology-based map symbolization network sharing service method in which the terminal can also independently select the map symbol library.

Above-mentioned technical problem of the present invention is mainly solved by following technical scheme:

A kind of map symbolization network sharing service method based on DCOM technology, it is characterized in that, comprises the following steps:

Step 1. The client creates a new map and specifies the scale of the created map, and loads the layer. At the same time, the client sends a symbolization request to the symbolization server, requesting the symbol database object SymbolDatabase;

Step 2. After the symbolization server receives the request and verifies that the client has passed the authorization, it creates a symbol database object SymbolDatabase on the symbolization server, and returns an interface ISymbolDB that can access the symbol database object SymbolDatabase to the client;

Step 3. After receiving the ISymolDB interface from the symbolization server, the client determines the elements to be symbolized, and sends a symbolization request to the symbolization server, and the symbolization server receives the symbolization request marshaled from the client Finally, scan the available symbol library server in the network and marshal the available map symbol library information to the client;

Step 4. The client specifies the required map symbol library according to the map symbol library information provided by the symbolization server, and sends the specified symbol library information to the symbolization server; the symbol database object SymbolDatabase of the symbolization server is based on the The map symbol library information provided by the terminal is imported into the corresponding map symbol library, and the client uses the ISymbolDB interface to list the symbol information contained in the map symbol library object SymbolDatabase;

Step 5, the client uses the ISymbolDB interface to generate a map symbol object Symbol at the symbolization server according to the specified element to be symbolized and the map symbol used;

Step 6. The client converts the geometric information of the element to be symbolized into a common data type through the stub proxy program, and marshals it to the server;

Step 7. After receiving the data marshaled by the client, the symbolization server unpacks the data through its stub agent, and hands the unpacked data to the symbol object Symbol of the symbolization server for symbolization;

Step 8. The symbolization server marshals the symbolized result back to the client through the stub proxy, and the client unpacks the received symbolized result and converts it into a symbolized result that the client can recognize ;

Step 9. The client will draw and display the converted symbolization result in step 8, and complete the symbolization process.

In the aforementioned DCOM technology-based map symbolization network sharing service method, in step 2, after the symbolization server receives the request, it verifies the client's authority, and chooses to perform the following steps:

Step 2.1. If the client’s authority fails to pass the verification of the symbolic server, send a rejection response message to the client. After receiving the response message from the symbolic server, the client unpacks the response message. If it is a rejection response from the server information, stop sending symbolization requests to the current symbolization server, search for other symbolization servers in the network, and repeat step 1; if all symbolization servers in the network are traversed, all received by the client are rejection responses information, the client terminates the symbolization request and completes the entire symbolization process.

Step 2.2. If the client authority is verified by the symbolization server, create a symbol database object SymbolDatabase on the symbolization server, and return an interface ISymolDB that can access the SymbolDatabase to the client.

In the aforementioned DCOM technology-based map symbolization network sharing service method, in step 2, the ISymbolDB received by the client and sent back by the symbolization server is an interface for operating the symbolization server for displaying Symbolize the information about the symbol library object SymbolDatabase on the server side and manipulate the symbol library object, including displaying point, line and surface symbols, the number of symbols, the scale of the symbol library, the creator, the production time, and map symbolization.

In the aforementioned DCOM technology-based map symbolization network sharing service method, the map symbol library can be provided by the symbolization server or exist on the local area network, wide area network or Internet where the symbolization server is located.

In the aforementioned DCOM technology-based map symbolization network sharing service method, in step 6, when performing map symbolization, the client must marshal the geometric information of the elements to be symbolized to the symbolization server, and Data marshaled to the symbolic server must be converted to COM-generated data types.

In the above-mentioned a kind of map symbolization network sharing service method based on DCOM technology, in described step 4, the symbol information in the symbol library object SymbolDatabase that the client utilizes the ISymbolDB interface to enumerate comprises symbol number, symbol library scale, symbol library Producer, symbol library production time.

Therefore, the present invention has the following advantages: based on Microsoft DCOM technology, map symbolization network sharing services can be provided, and the client can freely choose the symbolization server to reasonably achieve load balance between the network and the symbolization server; the symbol library server can be located in the symbolization The server can also be a distributed server, and the client can also choose a map symbol library independently.

Description of drawings

Fig. 1 is a schematic diagram of the system architecture of an embodiment of the present invention;

Figure 2 is a schematic diagram of the traditional symbolization process;

Fig. 3 is a schematic diagram of the map symbolization service mechanism of the present invention;

Fig. 4 is a schematic diagram of the relationship between each component object in the symbolization process of the present invention;

Fig. 5 is a schematic diagram of key steps of the present invention;

Detailed ways

The technical solutions of the present invention will be further specifically described below through the embodiments and in conjunction with the accompanying drawings.

Example:

In order to facilitate those skilled in the art to understand and implement the present invention, the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments.

First introduce DCOM, DCOM (Microsoft Distributed Component Object Model Distributed Component Object Model) is a series of Microsoft concepts and program interfaces. Using this interface, a client program object can request a server program object from another computer in the network. DCOM is based on the Component Object Model (COM), which provides a set of interfaces that allow communication between clients and servers on the same computer.

The system architecture operated by the embodiment of the present invention, as shown in FIG. 1 , includes three parts: a client, a symbolization server, and a symbol library server. The client is the initiator of the map symbolization network sharing service, responsible for initiating service requests and drawing and display of the final symbolization results; the symbolization server is the provider of map symbolization, responsible for responding to the client’s symbolization request and The symbolization result of is marshaled back to the client; the symbol library server provides the map symbols required for symbolizing shared symbols.

As shown in Figure 2, it is a traditional map symbolization process, initiating a symbolization request, responding to a symbolization request, and querying a map symbol library are all completed in the same process of the machine. The biggest difference between the present invention and the traditional symbolization process is that the symbolization service initiator and symbolization service responder can be distributed in different processes on different machines.

As shown in Figure 3, it is the map symbolization service mechanism of the present invention. In the embodiment, taking the symbolized point feature layer as an example, the specific process of the above-mentioned DCOM-based map symbolization network sharing service method is as follows:

1. The client creates a new map and specifies the scale of the created map, and then loads the point feature layer.

2. The client sends a symbolization request to the symbolization server, requesting the symbol database object SymbolDatabase, which is created on the symbolization server instead of the local client.

3. After receiving the symbolization request from the client, the symbolization server first verifies the permission of the client that issued the access request. The map symbol library is provided by the symbolization server, not the local client; and the map symbol library can be provided by the symbolization Provided by the server, it can also exist on the local area network, wide area network or Internet where the symbolization server is located.

3.1. If the client's authority fails to pass the verification of the symbolic server, it will send a rejection response message to the client. After receiving the response message from the symbolic server, the client will unpack the response message. If it is a rejection message from the server , then stop sending the symbolization request to the current symbolization server, search for other symbolization servers in the network, and repeat step 2. If after traversing all symbolization servers in the network, the client receives all rejection responses, the client terminates the symbolization request and completes the entire symbolization process.

3.2. If the client permission is verified by the symbolization server, create a symbol database object SymbolDatabase on the symbolization server, and return an interface ISymolDB that can access the SymbolDatabase to the client.

4. After receiving the ISymolDB interface from the symbolization server, the client determines the elements to be symbolized, and sends a symbolization request to the symbolization server.

5. After receiving the symbolization request from the client, the symbolization server scans the available symbol library server in the network and marshals the available map symbol library information to the client.

6. The client specifies the required map symbol library according to the map symbol library information provided by the symbolization server, and marshals the specified symbol library information to the symbolization server. When performing map symbolization, the local client must The geometry information of the element to be symbolized is marshaled to the symbolization server, and the data marshaled to the symbolization server must be converted into a common data type of COM.

7. The SymbolDatabase object of the symbolization server imports the corresponding map symbol library according to the map symbol library information provided by the client.

8. The client uses the ISymolDB interface to enumerate the symbol information in the symbol database object SymbolDatabase, including the number of symbols, the scale of the symbol database, the creator of the symbol database, and the creation time of the symbol database.

9. The client uses the ISymolDB interface to generate a map symbol object Symbol on the symbolization server according to the specified elements to be symbolized and the map symbols used.

10. The client converts the positioning geometry information of the element to be symbolized into a common COM data type through the stub proxy program, and marshals it to the symbolization server.

11. The symbolization server unpacks the data marshaled by the client through the stub agent on the server side, and hands the unpacked data to the symbol object Symbol located on the symbolization server for symbolization, map symbolization The process is symbolized by the symbolization server, not by the local client.

12. The symbolization server marshals the symbolized result back to the client through its stub agent.

13. The client unpacks the received symbolic result through its stub agent and converts it into a data type that the client can recognize.

14. Repeat step 4 to step 13 to complete the symbolization of all elements.

15. The client draws and displays the converted symbolization results of all elements, and completes the symbolization process of the current layer.

As shown in Figure 4, the relationship between the various component objects in the symbolization process is illustrated.

As shown in Fig. 5, the key steps of the present invention are briefly summarized.

In this embodiment, the participants of the map symbolization service are divided into three parts: the client, the symbolization server and the symbol library server.

1) The client is the caller of the symbolization service, which makes a symbolization request and finally obtains the symbolization result;

2) The symbolization server is the symbolization service provider, which responds to the client's symbolization request and finally returns the symbolization result;

3) The symbol library server is a shared platform that provides map symbol libraries, and provides map symbol library data for symbolization services.

It should be noted that the symbol library server is the map symbol required to provide symbolic shared symbols, and is the server where the map symbol library is located. The symbol library server can be located on the same server as the symbolization server, or it can be distributed.

The client is only responsible for providing the data to be symbolized and displaying the final symbolized results, while the symbolization process is completed by the symbolization server.

The specific embodiments described herein are merely illustrative of the spirit of the invention. Those skilled in the art to which the present invention belongs can make various modifications or supplements to the described specific embodiments or adopt similar methods to replace them, but they will not deviate from the spirit of the present invention or go beyond the definition of the appended claims range.

Claims (6)

1. the Cartographic Symbolization network share service method based on the DCOM technology is characterized in that, may further comprise the steps:

Step 1, the newly-built map of client are also specified the engineer's scale of the map of being set up, and load the required sketch map layer of wanting, and client is sent the symbolism request to the symbolism service end simultaneously, asks symbolic library object SymbolDatabase;

Step 2, the symbolism service end request of receiving and after the checking client authority passes through at symbolism service end Create Symbol storehouse object SymbolDatabase, and is returned the interface ISymbolDB of an addressable symbolic library object SymbolDatabase to client;

Step 3, client are behind the ISymolDB interface of receiving from the symbolism service end; Confirm to treat the key element of symbolism; Send the symbolism request to the symbolism service end; The symbolism service end after receiving the symbolism request of sending from client envelope, available symbolic library service end and send available map symbol library information in the scan for networks to the client envelope;

Step 4, client are specified needed map symbols bank according to the map symbol library information that the symbolism service end provides, and specified symbolic library information is sent to the symbolism service end; The symbolic library object SymbolDatabase of symbolism service end imports corresponding map symbols bank according to the map symbol library information that client provides, and client utilizes the ISymbolDB interfaces column to enumerate the symbolic information that is comprised among the map symbols bank object SymbolDatabase;

Step 5, client utilize the ISymbolDB interface to generate map symbol object Symbol in the symbolism service end according to the specified key element of treating symbolism and employed map symbol;

Step 6, client will treat that the geological information of the key element of symbolism converts general data type into through the counterfoil Agent, and envelope is delivered to the symbolism service end;

After step 7, symbolism service end receive that client is sealed the data of sending here, through its counterfoil agency data are carried out deblocking, and will separate the data of being honored as a queen and give the symbol object Symbol of symbolism service end to carry out symbolism;

Step 8, symbolism service end are sent the envelope of the result after the symbolism back to client through the counterfoil agency, and the result of client after with the symbolism of receiving carries out deblocking, and convert the result after the symbolism that client can discern into;

Symbolism result after step 9, client are changed completing steps 8 draws demonstration, accomplishes the symbolism process.

2. a kind of Cartographic Symbolization network share service method based on the DCOM technology according to claim 1 is characterized in that, in the described step 2, the symbolism service end is received request back and checking client authority, and selects to carry out following steps:

If step 2.1 client authority is not verified through the symbolism service end; Then send the information of rejecing response to client envelope, client behind the response message of receiving the symbolism service end, the deblocking response message; If from the information that rejects response of service end; Then stop sending the symbolism request, seek other symbolism service ends in the network, repeating step 1 to the current sign service end; If in the traverses network after all symbolism service end, client receives is the information of rejecing response, and whole symbolism process is accomplished in then client terminate symbolism request;

Step 2.2, if the client authority verify through the symbolism service end, return the interface ISymolDB of an addressable SymbolDatabase then at symbolism service end Create Symbol storehouse object SymbolDatabase, and to client.

3. a kind of Cartographic Symbolization network share service method according to claim 1 based on the DCOM technology; It is characterized in that; In the said step 2; The ISymbolDB that the symbolism service end envelope that client is received is sent back to is the interface that is used for the functional symbol service end; In order to the symbolic library object SymbolDatabase of displaying symbol service end for information about and handle the symbolic library object, comprise showing point-line-surface symbol, symbol numbers, symbolic library engineer's scale, wright, Production Time and carrying out Cartographic Symbolization.

4. a kind of Cartographic Symbolization network share service method according to claim 1 based on the DCOM technology; It is characterized in that map symbols bank can be provided or is present on LAN, wide area network or the Internet at symbolism service end place by the symbolism service end.

5. a kind of Cartographic Symbolization network share service method according to claim 1 based on the DCOM technology; It is characterized in that; In the said step 6; When carrying out Cartographic Symbolization, client must be delivered to the symbolism service end with the geological information of the key element of treating symbolism envelope, and the data that envelope is delivered to the symbolism service end must convert the general data type of COM into.

6. a kind of Cartographic Symbolization network share service method according to claim 1 based on the DCOM technology; It is characterized in that; In the said step 4, client utilizes the symbolic information among the symbolic library object SymbolDatabase that the ISymbolDB interfaces column enumerates to comprise symbol numbers, symbolic library engineer's scale, symbolic library wright, symbolic library Production Time.

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