如何检查SOAP Web服务连接

Question

I'm developing an android application using SOAP webservice. In this app, I need check the connectivity of the webservice, because if the connection is available i have to show the data in online mode and if the connection is not available i have to show the data in offline mode ie. I'm using SQLlite database to store the data from the webservice

How can my application test for availability of the server, to control whether the application runs in online or offline mode?

Answer 1

At design time you can point a web browser at the webservice and examine the response. It you don't get a response, or not what you expect, you can get more detail using Fiddler

At run-time you can simply attempt to access the server in a try/catch exception handler. Define a public bool IsOnline on something that's visible with appropriate scope, and set it true after successful execution and set it false in the exception handler. It's been decades since I used Java but this is the same approach you would use in practically any OO semiprocedural language, like C# or C++ or Java or for that matter VB.

Answer 2

For this , I followed this method

1. I create a Pogo Function (web-method) in my web-service (server) to to check connectivity

2. Create a method to in client side to call the web-method . While i Enter into the app for first time ,I call this client method from the phone using client function .Then wait for the response.The client method should be surrounded by try-catch block

3. If any exception or timed out happened the response will be null and go to exception stage.So buy checking the response . I set a flag (boolean or integer variable) on base of the state of response (null or not null) to decide off-line or on-line mode

Example with code

    public class CallSOAP {

private String SOAP_ACTION="your action url";
private String OPERATION_NAME="";//The web method OR web service you are going to call
private final String WSDL_TARGET_NAMESPACE=SOAP_ACTION;
private  final String SOAP_ADDRESS=Configuration.WEB_SERVICE_URL;//ip-address of serever where you host your service 
private Exception exception;
private String ErrorMsg="";
private String TERST_URL="" ;
public Object call(String MethodeName,ArrayList<PropertyInfo> Parameters){
  this.OPERATION_NAME=MethodeName;
  SoapObject request = new SoapObject(WSDL_TARGET_NAMESPACE, OPERATION_NAME);
 if(Parameters != null && Parameters.size()>0){
   for(PropertyInfo propertyInfo : Parameters){
      request.addProperty(propertyInfo);
 }
}

SoapSerializationEnvelope  envelope = new SoapSerializationEnvelope(SoapEnvelope.VER11);
envelope.dotNet= true;
envelope.setOutputSoapObject(request);
HttpTransportSE httpTransport =null;
if(!this.TERST_URL.equals(""))
  httpTransport = new HttpTransportSE(this.TERST_URL);
else
  httpTransport = new HttpTransportSE(SOAP_ADDRESS);
 Object Response =null;
 try{
    httpTransport.call(SOAP_ACTION+OPERATION_NAME, envelope);
    Response=envelope.getResponse();
  }
 catch (SocketTimeoutException ex) {
     this.ErrorMsg="Unable to connect";
      Response=null;
     this.exception=ex;
  }
  catch (IOException ie) {
   this.ErrorMsg="Unable to connect";
  Response=null;
   this.exception=ie;
  }
   catch (Exception e) {
    this.ErrorMsg="Unable to connect";
    Response=null;
    this.exception=e;
 }
      return Response;
   }
}

In the code ErrorMsg="Unable to connect"; shows the connection is not available now .So i set the response to null and you can pass this response to activity and check it over there

Refer this