StringFromFile (Apache JMeter API)

java.lang.Object
- org.apache.jmeter.functions.AbstractFunction
- - org.apache.jmeter.functions.StringFromFile

All Implemented Interfaces:

Function, TestStateListener
```
public class StringFromFile
extends AbstractFunction
implements TestStateListener
```
StringFromFile Function to read a String from a text file. Parameters: - file name - variable name (optional - defaults to StringFromFile_) Returns: - the next line from the file - or **ERR** if an error occurs - value is also saved in the variable for later re-use. Ensure that different variable names are used for each call to the function Notes:
- JMeter instantiates a single copy of each function for every reference in the test plan
- Function instances are shared between threads.
- Each StringFromFile instance reads the file independently. The output variable can be used to save the value for later use in the same thread.
- The file name is resolved at file (re-)open time; the file is initially opened on first execution (which could be any thread)
- the output variable name is resolved every time the function is invoked
Because function instances are shared, it does not make sense to use the thread number as part of the file name.
Since:

1.9

Constructor Summary

Constructors
Constructor and Description

StringFromFile()

Constructors
Constructor and Description
`StringFromFile()`

Method Summary

Methods
Modifier and Type	Method and Description
`String`	`execute(SampleResult previousResult, Sampler currentSampler)` N.B. execute() should be synchronized if function is operating with non-thread-safe objects (e.g. operates with files).
`List<String>`	`getArgumentDesc()` Return a list of strings briefly describing each parameter your function takes.
`String`	`getReferenceKey()` Return the name of your function.
`void`	`setParameters(Collection<CompoundVariable> parameters)` Note: This is always called even if no parameters are provided (versions of JMeter after 2.3.1)
`void`	`testEnded()` Called once for all threads after the end of a test.
`void`	`testEnded(String host)` Called once for all threads after the end of a test.
`void`	`testStarted()` Called just before the start of the test from the main engine thread.
`void`	`testStarted(String host)` Called just before the start of the test from the main engine thread.

Methods inherited from class org.apache.jmeter.functions.AbstractFunction
checkMinParameterCount, checkParameterCount, checkParameterCount, execute, getVariables

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - StringFromFile
```
public StringFromFile()
```
- Method Detail
  - execute
```
public String execute(SampleResult previousResult,
             Sampler currentSampler)
               throws InvalidVariableException
```
    N.B. execute() should be synchronized if function is operating with non-thread-safe objects (e.g. operates with files).
    JMeter ensures setParameters() happens-before execute(): setParameters is executed in main thread, and worker threads are started after that.
    
    Specified by:
    
    execute in interface Function
    
    Specified by:
    
    execute in class AbstractFunction
    
    Parameters:
    previousResult - The previous SampleResult
    currentSampler - The current Sampler
    
    Returns:
    The replacement value, which was generated by the function
    
    Throws:
    
    InvalidVariableException - - when the variables for the function call can't be evaluated
    See Also:
    Function.execute(SampleResult, Sampler)
  - setParameters
```
public void setParameters(Collection<CompoundVariable> parameters)
                   throws InvalidVariableException
```
    Note: This is always called even if no parameters are provided (versions of JMeter after 2.3.1)
    
    Specified by:
    
    setParameters in interface Function
    
    Specified by:
    
    setParameters in class AbstractFunction
    
    Parameters:
    parameters - The parameters for the function call
    
    Throws:
    
    InvalidVariableException - - when the variables for the function call can't be evaluated
    See Also:
    Function.setParameters(Collection)
  - getReferenceKey
```
public String getReferenceKey()
```
    Return the name of your function. Convention is to prepend "__" to the name (ie "__regexFunction")
    
    Specified by:
    
    getReferenceKey in interface Function
    
    Specified by:
    
    getReferenceKey in class AbstractFunction
    
    Returns:
    The name of the funtion
    See Also:
    Function.getReferenceKey()
  - getArgumentDesc
```
public List<String> getArgumentDesc()
```
    Return a list of strings briefly describing each parameter your function takes. Please use JMeterUtils.getResString(resource_name) to grab a resource string. Otherwise, your help text will be difficult to internationalize. This list is not optional. If you don't wish to write help, you must at least return a List containing the correct number of blank strings, one for each argument.
    
    Specified by:
    
    getArgumentDesc in interface Function
    
    Returns:
    List with brief descriptions for each parameter the function takes
  - testStarted
```
public void testStarted()
```
    Called just before the start of the test from the main engine thread. This is before the test elements are cloned. Note that not all the test variables will have been set up at this point.
    
    N.B. testStarted() and testEnded() are called from different threads.
    
    Specified by:
    
    testStarted in interface TestStateListener
    
    See Also:
    StandardJMeterEngine.run()
  - testStarted
```
public void testStarted(String host)
```
    Called just before the start of the test from the main engine thread. This is before the test elements are cloned. Note that not all the test variables will have been set up at this point.
    
    N.B. testStarted() and testEnded() are called from different threads.
    
    Specified by:
    
    testStarted in interface TestStateListener
    
    Parameters:
    host - name of host
    See Also:
    StandardJMeterEngine.run()
  - testEnded
```
public void testEnded()
```
    Called once for all threads after the end of a test. This will use the same element instances as at the start of the test.
    
    N.B. testStarted() and testEnded() are called from different threads.
    
    Specified by:
    
    testEnded in interface TestStateListener
    
    See Also:
    StandardJMeterEngine.stopTest()
  - testEnded
```
public void testEnded(String host)
```
    Called once for all threads after the end of a test. This will use the same element instances as at the start of the test.
    
    N.B. testStarted() and testEnded() are called from different threads.
    
    Specified by:
    
    testEnded in interface TestStateListener
    
    Parameters:
    host - name of host
    See Also:
    StandardJMeterEngine.stopTest()

Class StringFromFile

Constructor Summary

Method Summary

Methods inherited from class org.apache.jmeter.functions.AbstractFunction

Methods inherited from class java.lang.Object

Constructor Detail

StringFromFile

Method Detail

execute

setParameters

getReferenceKey

getArgumentDesc

testStarted

testStarted

testEnded

testEnded