__groovy

Also documented in context in the full Functions and Variables reference.

TL;DR: __groovy evaluates an inline Groovy expression and returns its result — useful for a one-line computation directly in a field, without a full JSR223 Sampler/PreProcessor element.

The __groovy function evaluates Apache Groovy scripts passed to it, and returns the result.

If the property “groovy.utilities” is defined, it will be loaded by the ScriptEngine. This can be used to define common methods and variables. There is a sample init file in the bin directory: utility.groovy.

The following variables are set before the script is executed:

• log - the Logger for the groovy function (*)
• ctx - JMeterContext object
• vars - JMeterVariables object
• props - JMeterProperties (class java.util.Properties) object
• threadName - the threadName (String)
• sampler - the current Sampler, if any
• prev - the previous SampleResult, if any
• OUT - System.out

(*) means that this is set before the init file, if any, is processed. Other variables vary from invocation to invocation.

Note

When using this function please use the variables defined above rather than using string replacement to access a variable in your script. Following this pattern will ensure that your tests are performant by ensuring that the Groovy can be cached.

For instance don’t do the following:

\${__groovy("\${myVar}".substring(0\,2))}

Imagine that the variable myVar changes with each transaction, the Groovy above cannot be cached as the script changes each time.

Instead do the following, which can be cached:

\${__groovy(vars.get("myVar").substring(0\,2))}

Name	Required	Description
Expression to evaluate	Yes	An Apache Groovy script (not a file name) :::note Argument values that themselves contain commas should be escaped as necessary. If you need to include a comma in your parameter value, escape it like this: ‘\,’ :::
Name of variable	No	A reference name for reusing the value computed by this function.

Example:

\${__groovy(123*456)}

: returns 56088

\${__groovy(vars.get("myVar").substring(0\,2))}

: If var’s value is JMeter, it will return JM as it runs String.substring(0,2). Note that , has been escaped to \,

Note

Remember to include any necessary quotes for text strings and JMeter variables that represent text strings.

Example

${__groovy(1+1)}                              → 2
${__groovy(vars.get("count") as Integer + 1)} → increment a JMeter variable

For anything beyond a short expression — multi-line logic, imports, error handling — a JSR223 PreProcessor or PostProcessor is more maintainable and easier to debug than a one-liner buried inside a field. See the JSR223 Groovy Scripting Guide.

Related

• Functions and Variables Guide
• Regex Extractor Builder
• JSR223 Groovy Scripting Guide
• Full Functions Reference
• Component Reference