gsoap 远程调用举例

心已赠人 2023-02-12 09:29 142阅读 0赞

## gsoap 远程调用举例 ##

gsoap生成Web Service框架代码。这里通过gsoap官网\*\*Example XML SOAP server ©**和**Example XML SOAP client ©\*\*例子来实现sgoap生成框架，并实现远程调用。

gsoap官网例程：https://www.genivia.com/dev.html\#server-c

![img][]

#### 1、SOAP服务器 ####

将gsoap安装路径下的`import`和`custom`文件夹，`stdsoap2.h`和`stdsoap2.h`拷贝到需要生成文件的路径中。

利用`wsdl2h`工具和**wsdl**文档来生成`.h`服务接口。然后通过`soapcpp2`工具和`.h`文件生成底层代码和接口。

$ wsdl2h -c -o calc.h http://www.genivia.com/calc.wsdl
    $ soapcpp2 -S -L -x calc.h

最终生成服务器代码。这里需要用到的文件主要有`soapC.c soapServer.c stdsoap2.c calcserver.c stdsoap2.h soapStub.h soapH.h`。`calcserver.c`是我手动创建的，用来实现wsdl文档中的接口和主函数。  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2R1YXBwbGU_size_16_color_FFFFFF_t_70]  
`calcserver.c`文件主要内容如下，代码来自gsoap官网案例。代码稍微有点问题，明明是C的例子，里面却出现了C++代码，这里直接将C++代码全部注释掉，不适用`pow`功能。

#include "calc.nsmap" // XML namespace mapping table (only needed once at the global level)
    #include "soapH.h" // server stubs, serializers, etc.
    
    int main()
    { 
      struct soap *soap = soap_new1(SOAP_XML_INDENT);
      soap_set_namespaces(&soap, namespaces);
      if (!soap_valid_socket(soap_bind(soap, NULL, 8080, 10))) // port 8080 and small BACKLOG queue for iterative servers
        exit(EXIT_FAILURE);
        /* 阻塞在soap_accept处，当有远程调用产生时，接收远程调用并进行相应的处理。 */
      while (soap_valid_socket(soap_accept(soap)))
      { 
          printf("accept ok\r\n");
        if (soap_serve(soap) != SOAP_OK)
          break;
        soap_destroy(soap); // delete deserialized C++ instances
        soap_end(soap);     // delete other managed data
      }
      soap_print_fault(soap, stderr);
      soap_free(soap); // free the soap struct context data
    }
    
    /* 以下是关于wsdl接口的实现。当客户端对服务器进行远程调用时，将会调用以下对应的函数。 */
    int ns2__add(struct soap *soap, double a, double b, double *result)
    { 
        printf("ns2__add called\r\n");
        /* 这里把加法改成乘法，证明我们的调用没有问题。 */
      *result = a * b;
      return SOAP_OK;
    }
    int ns2__sub(struct soap *soap, double a, double b, double *result)
    { 
      *result = a - b;
      return SOAP_OK;
    }
    int ns2__mul(struct soap *soap, double a, double b, double *result)
    { 
      *result = a * b;
      return SOAP_OK;
    }
    int ns2__div(struct soap *soap, double a, double b, double *result)
    { 
      if (b == 0.0)
      { 
        char *msg = (char*)soap_malloc(soap, 1024);
        snprintf(msg, 1024, "Trying to divide %f by zero", a);
        return soap_sender_fault(soap, msg, NULL);
      }
      *result = a / b;
      return SOAP_OK;
    }
    int ns2__pow(struct soap *soap, double a, double b, double *result)
    { 
    // *result = ::pow(a, b);
    // // soap_errno is like errno, but compatible with Win32
    // if (soap_errno == EDOM)
    // { 
    // char *msg = (char*)soap_malloc(soap, 1024);
    // snprintf(msg, 1024, "<error xmlns=\"http://tempuri.org/\">Can't take power of %f to %f</error>", a, b);
    // return soap_sender_fault(soap, "Power function domain error", s);
    // }
      return SOAP_OK;
    }

完成`calcserver.c`后，编译server并运行。我这里是通过wsl编译运行的。

$ gcc soapC.c soapServer.c stdsoap2.c calcserver.c -o calcserver
    $ ./calcserver

这时服务器的ip使我们的本机**IP：192.168.x.x**，然后端口号是上面设置的**8080**。服务器已经搭建完成了，接下来进行client端开发，来访问我们的服务器。

--------------------

#### 2、SOAP客户端 ####

Client操作流程和Server类似。同样的操作步骤，修改命令参数即可。这里将Client代码路径修改一下，不要和Server放在同一路径下，因为生成的`soapStub.h`有略微差异，后面不方便同时修改客户端服务端代码。

根据gsoap官网的教程，生成代码。操作如下：

$ wsdl2h -c -o calc.h http://www.genivia.com/calc.wsdl
    $ soapcpp2 -CL -x calc.h

最终生成客户端代码。这里需要用到的文件主要有`soapC.c soapClient.c stdsoap2.c calcclient.c stdsoap2.h soapStub.h soapH.h`。`calcClient.c`是我手动创建的，用来实现main函数对Server进行访问调用。  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2R1YXBwbGU_size_16_color_FFFFFF_t_70 1]  
`calcserver.c`文件主要内容如下，代码来自gsoap官网案例。这里对ns2\_\_add进行远程调用，发送调用信息给服务器，服务器收到调用信息再调用具体实现函数。**因为之前已经修改过add了，所以这里调用以后应该是乘法结构。**

#include "calc.nsmap" // XML namespace mapping table (only needed once at the global level)
    #include "soapH.h" // client stubs, serializers, etc.
    
    int main()
    { 
      struct soap *soap = soap_new(); // allocate and initialize a context
      double sum;
      soap->connect_timeout = 10; // connect within 10s
        soap->send_timeout = 5;     // send timeout is 5s
        soap->recv_timeout = 5;     // receive timeout is 5s
        soap->socket_flags = MSG_NOSIGNAL;
      if (soap_call_ns2__add(soap, NULL, NULL, 1.23, 4.56, &sum) == SOAP_OK)
        printf("Sum = %g\n", sum);
      else
        soap_print_fault(soap, stderr);
      soap_destroy(soap); // delete managed deserialized C++ instances
      soap_end(soap);     // delete other managed data
      soap_free(soap);    // free the soap struct context data
    }

它这里的给的例子不是调用我们自己服务器的，所以需要将它调用的链接修改我们自己服务器的地址和端口号。在`soapClient.c`中，对相应的代码进行修改，`soap_endpoint`是用来控制访问地址的，这里修改成我们服务器的。

SOAP_FMAC5 int SOAP_FMAC6 soap_send_ns2__add(struct soap *soap, const char *soap_endpoint, const char *soap_action, double a, double b)
    { 	struct ns2__add soap_tmp_ns2__add;
    	if (soap_endpoint == NULL)
    		// soap_endpoint = "http://websrv.cs.fsu.edu/~engelen/calcserver.cgi";
    		soap_endpoint = "192.168.x.x:8080";

完成`calcclient.c`后，编译client并运行。我这里是通过wsl编译运行的。

$ gcc soapC.c calcclient.c soapClient.c stdsoap2.c -o calcclient
    $ ./calcclient

输出结果如下：

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2R1YXBwbGU_size_16_color_FFFFFF_t_70 2]

--------------------

#### 3、总结 ####

以上就是利用gsoap工具通过wsdl文档来生成web service框架，我们只需要完成wsdl文档的接口就行了。

--------------------

[img]: https://img-blog.csdn.net/20170517210400296?watermark/2/text/aHR0cDovL2Jsb2cuY3Nkbi5uZXQvYmVua2FveWE=/font/5a6L5L2T/fontsize/400/fill/I0JBQkFCMA==/dissolve/70/gravity/SouthEast
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[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2R1YXBwbGU_size_16_color_FFFFFF_t_70 2]: https://img-blog.csdnimg.cn/20200525174421989.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2R1YXBwbGU=,size_16,color_FFFFFF,t_70