by, 04-27-2012 at 08:26 PM (1631 Views)
Listeners provide access to the information JMeter gathers about the test cases while JMeter runs. The Graph Results listener plots the response times on a graph. The "View Results Tree" Listener shows details of sampler requests and responses, and can display basic HTML and XML representations of the response. Other listeners provide summary or aggregation information.
Additionally, listeners can direct the data to a file for later use. Every listener in JMeter provides a field to indicate the file to store data to. There is also a Configuration button which can be used to choose which fields to save, and whether to use CSV or XML format. Note that all Listeners save the same data; the only difference is in the way the data is presented on the screen.
Listeners can be added anywhere in the test, including directly under the test plan. They will collect data only from elements at or below their level.