Invocation Context¶

The Backendless container which hosts and runs the services code provides a special object for every method invocation. The object is an instance of the com.backendless.servercode.InvocationContext class and provides access to the following data:

Application ID - id of the application in which context the method is invoked.
```
String applicationId = InvocationContext.getAppId();
```
User ID - objectId of the currently logged in user whose identity is used to invoke the method. A value for this parameter is not present if there is no logged in user (or if the user-token header is not passed for the REST invocations).
```
String userObjectId = InvocationContext.getUserId();
```
User token - value of the user-token header sent by the client application when invoking the service.
```
String userToken = InvocationContext.getUserToken();
```
User roles - an array of the role names of the logged-in user (if any) who made the API call.
```
InvocationContext.getUserId();
```

Device type - the type of the device which initiated the method invocation.

DeviceType deviceType = InvocationContext.getUserId();

// get device type corresponding to the API Key. Possible values are:
// "IOS", "ANDROID", "JS", "REST", "BL" (business logic)
String deviceTypeName = deviceType.name();

// get role name corresponding to the API key. Possible values are:
// "IOSUser", "AndroidUser", "JSUser", "RestUser", "ServerCodeUser"
String deviceTypeRoleName = deviceType.getRoleName();

HTTP headers - HTTP headers sent by the client application when invoking the service.
```
Map<String, String> httpHeaders = InvocationContext.getHttpHeaders();
```