Interface BackendListenerClient
- All Known Implementing Classes:
AbstractBackendListenerClient
,GraphiteBackendListenerClient
JMeter will create one instance of a BackendListenerClient implementation for each user/thread in the test. Additional instances may be created for internal use by JMeter (for example, to find out what parameters are supported by the client).
When the test is started, setupTest() will be called on each thread's BackendListenerClient instance to initialize the client. Then handleSampleResult() will be called for each SampleResult notification. Finally, teardownTest() will be called to allow the client to do any necessary clean-up.
The JMeter BackendListener GUI allows a list of parameters to be defined for the
test. These are passed to the various test methods through the
BackendListenerContext
. A list of default parameters can be defined
through the getDefaultParameters() method. These parameters and any default
values associated with them will be shown in the GUI. Users can add other
parameters as well.
When possible, Listeners should extend AbstractBackendListenerClient
rather than implementing BackendListenerClient
directly. This should protect your tests from future changes to the
interface. While it may be necessary to make changes to the BackendListenerClient
interface from time to time (therefore requiring changes to any
implementations of this interface), we intend to make this abstract class
provide reasonable default implementations of any new methods so that
subclasses do not necessarily need to be updated for new versions.
Implementing BackendListenerClient directly will continue to be supported for
cases where extending this class is not possible (for example, when the
client class is already a subclass of some other class).
- Since:
- 2.13
-
Method Summary
Modifier and TypeMethodDescriptioncreateSampleResult
(BackendListenerContext context, SampleResult result) Create a copy of SampleResult, this method is here to allow customizing what is kept in the copy, for example copy could remove some useless fields.Provide a list of parameters which this test supports.void
handleSampleResults
(List<SampleResult> sampleResults, BackendListenerContext context) Handle sampleResults, this can be done in many ways: Write to a file Write to a distant server ...void
setupTest
(BackendListenerContext context) Do any initialization required by this client.void
teardownTest
(BackendListenerContext context) Do any clean-up required at the end of a test run.
-
Method Details
-
setupTest
Do any initialization required by this client. It is generally recommended to do any initialization such as getting parameter values in the setupTest method rather than the runTest method in order to add as little overhead as possible to the test.- Parameters:
context
- the context to run with. This provides access to initialization parameters. Context is readonly- Throws:
Exception
- when setup fails
-
handleSampleResults
Handle sampleResults, this can be done in many ways:- Write to a file
- Write to a distant server
- ...
- Parameters:
sampleResults
- List ofSampleResult
context
- the context to run with. This provides access to initialization parameters.
-
teardownTest
Do any clean-up required at the end of a test run.- Parameters:
context
- the context to run with. This provides access to initialization parameters.- Throws:
Exception
- when tear down fails
-
getDefaultParameters
Arguments getDefaultParameters()Provide a list of parameters which this test supports. Any parameter names and associated values returned by this method will appear in the GUI by default so the user doesn't have to remember the exact names. The user can add other parameters which are not listed here. If this method returns null then no parameters will be listed. If the value for some parameter is null then that parameter will be listed in the GUI with an empty value.- Returns:
- a specification of the parameters used by this test which should be listed in the GUI, or null if no parameters should be listed.
-
createSampleResult
Create a copy of SampleResult, this method is here to allow customizing what is kept in the copy, for example copy could remove some useless fields. Note that if it returns null, the sample result is not put in the queue. Defaults to returning result.- Parameters:
context
-BackendListenerContext
result
-SampleResult
- Returns:
SampleResult
-