In order to define your own variables and reuse them in your tests, it’s easier to use the User Defined Variables from JMeter.
Here is how to create a variable and use it in an HTTP Request from your JMeter Test Plan.
Steps
1. Open JMeter (here is a more detailed post on how to install JMeter) and Add a Thread Group to your Test Plan
2. Add a HTTP Request Sampler to your Thread Group
3. Right-Click the Thread Group and add User Defined Variables Config Element in your JMeter test
4. Create a new variable: var1 with value www.example.com
5. Go to the HTTP Request and add the variable name where you want to be replaced with its value, use ${var1}
6. Add a View Results Tree Listener in order to easily see the results of your request.
7. Make the request and you can see that the ${var1} was replaced with www.example.com in the HTTP Request
8. Add the ${var1} also in the name of the HTTP Request sampler and you can see the request has the value of the user defined variable var1
Notes:
- suggestion: for simplicity use User Defined Variables only at the beginning of a Thread Group
- all User Defined Variables from a test plan are processed at the beginning no matter where they are added or placed in the JMeter Test Plan
- JMeter User Defined Variables should not be used with functions that generate different results each time they are called
- use User Parameters for defining variables during a test run instead of User Defined Variables
- User Defined Variables are processed in the order they are added in the test plan, from TOP to BOTTOM
- If, in your Test Plan,you have more than one Thread Group, use different names for different values, as UDVs are shared between Thread Groups.
- You can reference variables defined in earlier UDVs or on the Test Plan.