Class Awaitility

java.lang.Object
org.awaitility.Awaitility

public class Awaitility extends Object
Awaitility is a small Java DSL for synchronizing (waiting for) asynchronous operations. It makes it easy to test asynchronous code. Examples:

 

Wait at most 5 seconds until customer status has been updated:

 await().atMost(5, SECONDS).until(customerStatusHasUpdated());
 

Wait forever until the call to orderService.orderCount() is greater than 3.

 await().forever().until(() -> orderService.orderCount()), greaterThan(3));
 

Wait 300 milliseconds until field in object myObject with name fieldName and of type int.class is equal to 4.

 await().atMost(300, MILLISECONDS).until(fieldIn(orderService).withName("fieldName").andOfType(int.class), equalTo(3));
 

Advanced usage: Use a poll interval of 100 milliseconds with an initial delay of 20 milliseconds until customer status is equal to "REGISTERED". This example also uses a named await by specifying an alias ("customer registration"). This makes it easy to find out which await statement that failed if you have multiple awaits in the same test.

 with().pollInterval(ONE_HUNDERED_MILLISECONDS).and().with().pollDelay(20, MILLISECONDS).await("customer registration")
         .until(customerStatus(), equalTo(REGISTERED));
 

You can also specify a default timeout, poll interval and poll delay using:

 Awaitility.setDefaultTimeout(..)
 Awaitility.setDefaultPollInterval(..)
 Awaitility.setDefaultPollDelay(..)
 

You can also reset to the default values using reset(). In order to use Awaitility effectively it's recommended to statically import the following methods from the Awaitility framework:

 

  • org.awaitility.Awaitlity.*
  • org.awaitility.Durations.*
It may also be useful to import these methods:
  • java.util.concurrent.TimeUnit.*
  • org.hamcrest.Matchers.*
  • org.junit.Assert.*

 

A word on poll interval and poll delay: Awaitility starts to check the specified condition (the one you create using the Awaitility DSL) matches for the first time after a "poll delay" (the initial delay before the polling begins). By default Awaitility uses the same poll delay as poll interval which means that it checks the condition periodically first after the given poll delay, and subsequently with the given poll interval; that is conditions are checked after pollDelay then pollDelay+pollInterval, then pollDelay + 2 pollInterval, and so on.
Note: If you change the poll interval the poll delay will also change to match the specified poll interval unless you've specified a poll delay explicitly.

 

Note that since Awaitility uses polling to verify that a condition matches it's not intended to use it for precise performance testing.

 

IMPORTANT: Awaitility does nothing to ensure thread safety or thread synchronization! This is your responsibility! Make sure your code is correctly synchronized or that you are using thread safe data structures such as volatile fields or classes such as AtomicInteger and ConcurrentHashMap.
  • Field Details

    • DEFAULT_POLL_DELAY

      private static final Duration DEFAULT_POLL_DELAY
    • DEFAULT_POLL_INTERVAL

      private static final PollInterval DEFAULT_POLL_INTERVAL
    • defaultPollInterval

      private static volatile PollInterval defaultPollInterval
      The default poll interval (fixed 100 ms).
    • defaultWaitConstraint

      private static volatile WaitConstraint defaultWaitConstraint
      The default wait constraint (10 seconds).
    • defaultPollDelay

      private static volatile Duration defaultPollDelay
      The default poll delay
    • defaultCatchUncaughtExceptions

      private static volatile boolean defaultCatchUncaughtExceptions
      Catch all uncaught exceptions by default?
    • defaultExceptionIgnorer

      private static volatile ExceptionIgnorer defaultExceptionIgnorer
      Ignore caught exceptions by default?
    • defaultConditionEvaluationListener

      private static volatile ConditionEvaluationListener defaultConditionEvaluationListener
      Default listener of condition evaluation results.
    • defaultExecutorLifecycle

      private static volatile ExecutorLifecycle defaultExecutorLifecycle
      Default condition evaluation executor service.
    • defaultFailFastCondition

      private static volatile FailFastCondition defaultFailFastCondition
      If this condition if _ever_ false, indicates our condition will _never_ be true.
  • Constructor Details

    • Awaitility

      public Awaitility()
  • Method Details

    • catchUncaughtExceptionsByDefault

      public static void catchUncaughtExceptionsByDefault()
      Instruct Awaitility to catch uncaught exceptions from other threads by default. This is useful in multi-threaded systems when you want your test to fail regardless of which thread throwing the exception. Default is true.
    • doNotCatchUncaughtExceptionsByDefault

      public static void doNotCatchUncaughtExceptionsByDefault()
      Instruct Awaitility not to catch uncaught exceptions from other threads. Your test will not fail if another thread throws an exception.
    • ignoreExceptionsByDefault

      public static void ignoreExceptionsByDefault()
      Instruct Awaitility to ignore caught or uncaught exceptions during condition evaluation. Exceptions will be treated as evaluating to false. Your test will not fail upon an exception, unless it times out.
    • ignoreExceptionByDefault

      public static void ignoreExceptionByDefault(Class<? extends Throwable> exceptionType)
      Instruct Awaitility to ignore caught exception of the given type during condition evaluation. Exceptions will be treated as evaluating to false. Your test will not fail upon an exception matching the supplied exception type, unless it times out.
    • ignoreExceptionsByDefaultMatching

      public static void ignoreExceptionsByDefaultMatching(Predicate<? super Throwable> predicate)
      Instruct Awaitility to ignore caught exceptions matching the given predicate during condition evaluation. Exceptions will be treated as evaluating to false. Your test will not fail upon an exception matching the supplied predicate, unless it times out.
    • ignoreExceptionsByDefaultMatching

      public static void ignoreExceptionsByDefaultMatching(org.hamcrest.Matcher<? super Throwable> matcher)
      Instruct Awaitility to ignore caught exceptions matching the supplied matcher during condition evaluation. Exceptions will be treated as evaluating to false. Your test will not fail upon an exception matching the supplied exception type, unless it times out.
    • pollInSameThread

      public static void pollInSameThread()
      Instructs Awaitility to execute the polling of the condition from the same as the test. This is an advanced feature and you should be careful when combining this with conditions that wait forever (or a long time) since Awaitility cannot interrupt the thread when using the same thread as the test. For safety you should always combine tests using this feature with a test framework specific timeout, for example in JUnit:
      Since:
      3.0.0
    • pollExecutorService

      public static void pollExecutorService(ExecutorService executorService)
      Specify the executor service whose threads will be used to evaluate the poll condition in Awaitility. Note that the executor service must be shutdown manually! This is an advanced feature and it should only be used sparingly.
      Parameters:
      executorService - The executor service that Awaitility will use when polling condition evaluations
      Since:
      3.0.0
    • pollThread

      public static void pollThread(Function<Runnable,Thread> threadSupplier)
      Specify a thread supplier whose thread will be used to evaluate the poll condition in Awaitility. The supplier will be called only once and the thread it returns will be reused during all condition evaluations. This is an advanced feature and it should only be used sparingly.
      Parameters:
      threadSupplier - A supplier of the thread that Awaitility will use when polling
      Since:
      3.0.0
    • reset

      public static void reset()
      Reset the timeout, poll interval, poll delay, uncaught exception handling to their default values:

       

      • timeout - 10 seconds
      • poll interval - 100 milliseconds
      • poll delay - 100 milliseconds
      • Catch all uncaught exceptions - true
      • Do not ignore caught exceptions
      • Don't handle condition evaluation results
      • Don't log anything
      • No fail fast condition
    • await

      public static ConditionFactory await()
      Start building an await statement.
      Returns:
      the condition factory
    • await

      public static ConditionFactory await(String alias)
      Start building a named await statement. This is useful is cases when you have several awaits in your test and you need to tell them apart. If a named await timeout's the alias will be displayed indicating which await statement that failed.
      Parameters:
      alias - the alias that will be shown if the await timeouts.
      Returns:
      the condition factory
    • catchUncaughtExceptions

      public static ConditionFactory catchUncaughtExceptions()
      Catching uncaught exceptions in other threads. This will make the await statement fail even if exceptions occur in other threads. This is the default behavior.
      Returns:
      the condition factory
    • dontCatchUncaughtExceptions

      public static ConditionFactory dontCatchUncaughtExceptions()
      Don't catch uncaught exceptions in other threads. This will not make the await statement fail if exceptions occur in other threads.
      Returns:
      the condition factory
    • with

      public static ConditionFactory with()
      Start constructing an await statement with some settings. E.g.

       with().pollInterval(20, MILLISECONDS).await().until(somethingHappens());
       
      Returns:
      the condition factory
    • given

      public static ConditionFactory given()
      Start constructing an await statement given some settings. E.g.

       given().pollInterval(20, MILLISECONDS).then().await().until(somethingHappens());
       
      Returns:
      the condition factory
    • waitAtMost

      public static ConditionFactory waitAtMost(Duration timeout)
      An alternative to using await() if you want to specify a timeout directly.
      Parameters:
      timeout - the timeout
      Returns:
      the condition factory
    • waitAtMost

      public static ConditionFactory waitAtMost(long value, TimeUnit unit)
      An alternative to using await() if you want to specify a timeout directly.
      Parameters:
      value - the value
      unit - the unit
      Returns:
      the condition factory
    • setDefaultPollInterval

      public static void setDefaultPollInterval(long pollInterval, TimeUnit unit)
      Sets the default poll interval that all await statements will use.
      Parameters:
      pollInterval - the poll interval
      unit - the unit
    • setDefaultPollDelay

      public static void setDefaultPollDelay(long pollDelay, TimeUnit unit)
      Sets the default poll delay all await statements will use.
      Parameters:
      pollDelay - the poll delay
      unit - the unit
    • setDefaultTimeout

      public static void setDefaultTimeout(long timeout, TimeUnit unit)
      Sets the default timeout all await statements will use.
      Parameters:
      timeout - the timeout
      unit - the unit
    • setDefaultPollInterval

      public static void setDefaultPollInterval(Duration pollInterval)
      Sets the default poll interval that all await statements will use.
      Parameters:
      pollInterval - the new default poll interval
    • setDefaultPollInterval

      public static void setDefaultPollInterval(PollInterval pollInterval)
      Sets the default poll interval that all await statements will use.
      Parameters:
      pollInterval - the new default poll interval
    • setDefaultPollDelay

      public static void setDefaultPollDelay(Duration pollDelay)
      Sets the default poll delay that all await statements will use.
      Parameters:
      pollDelay - the new default poll delay
    • setDefaultTimeout

      public static void setDefaultTimeout(Duration defaultTimeout)
      Sets the default timeout that all await statements will use.
      Parameters:
      defaultTimeout - the new default timeout
    • setDefaultConditionEvaluationListener

      public static void setDefaultConditionEvaluationListener(ConditionEvaluationListener defaultConditionEvaluationListener)
      Sets the default condition evaluation listener that all await statements will use.
      Parameters:
      defaultConditionEvaluationListener - handles condition evaluation each time evaluation of a condition occurs. Works only with Hamcrest matcher-based conditions.
    • setLoggingListener

      public static void setLoggingListener(ConditionEvaluationListener loggingListener)
      Sets the default logging condition evaluation listener that all await statements will use. Method could override result of usage setDefaultConditionEvaluationListener(ConditionEvaluationListener).
      Parameters:
      loggingListener - logging condition evaluation each time evaluation of a condition occurs.
      See Also:
    • setLogging

      public static void setLogging(Consumer<String> logPrinter)
      Sets the default logging condition evaluation listener that all await statements will use. Method could override result of usage setDefaultConditionEvaluationListener(ConditionEvaluationListener) with custom consumer.
      Parameters:
      logPrinter - consumer for condition logging
      See Also:
    • setDefaultLogging

      public static void setDefaultLogging()
      Sets the default logging condition evaluation listener that all await statements will use. Method could override result of usage setDefaultConditionEvaluationListener(ConditionEvaluationListener) with logging to System.out.
      See Also:
    • setDefaultFailFastCondition

      public static void setDefaultFailFastCondition(Callable<Boolean> defaultFailFastCondition)
      If the supplied Callable ever returns false, it indicates our condition will never be true, and if so fail the system immediately. Throws a TerminalFailureException if fail fast condition evaluates to true. If you want to specify a more descriptive error message then use setDefaultFailFastCondition(String, Callable).
      Parameters:
      defaultFailFastCondition - The terminal failure condition
      See Also:
    • setDefaultFailFastCondition

      public static void setDefaultFailFastCondition(ThrowingRunnable defaultFailFastAssertion)
      If the supplied failFastAssertion ever returns throws an exception, it indicates our condition will never be true, and if so fail the system immediately. This allows you to use a more descriptive error message of why the fail-fast condition failed instead of using setDefaultFailFastCondition(String, Callable).
      Parameters:
      defaultFailFastAssertion - The terminal failure assertion
      See Also:
    • setDefaultFailFastCondition

      public static void setDefaultFailFastCondition(String failFastFailureReason, ThrowingRunnable defaultFailFastAssertion)
      If the supplied failFastAssertion ever returns throws an exception, it indicates our condition will never be true, and if so fail the system immediately. This allows you to use a more descriptive error message of why the fail-fast condition failed instead of using setDefaultFailFastCondition(String, Callable).
      Parameters:
      failFastFailureReason - A descriptive reason why the fail fast condition has failed, will be included in the TerminalFailureException thrown if failFastAssertion throws an exception.
      defaultFailFastAssertion - The terminal failure assertion
      See Also:
    • setDefaultFailFastCondition

      public static void setDefaultFailFastCondition(String failFastFailureReason, Callable<Boolean> defaultFailFastCondition)
      If the supplied Callable ever returns false, it indicates our condition will never be true, and if so fail the system immediately. Throws a TerminalFailureException if fail fast condition evaluates to true.
      Parameters:
      defaultFailFastCondition - The terminal failure condition
      failFastFailureReason - A descriptive reason why the fail fast condition has failed, will be included in the TerminalFailureException thrown if failFastCondition evaluates to true.
    • fieldIn

      public static FieldSupplierBuilder fieldIn(Object object)
      Await until an instance field matches something. E.g.

       await().until(fieldIn(service).ofType(int.class).andWithName("fieldName"), greaterThan(2));
       

      Here Awaitility waits until a field with name fieldName and of the int.class in object service is greater than 2.

      Note that the field must be thread-safe in order to guarantee correct behavior.

      Parameters:
      object - The object that contains the field.
      Returns:
      A field supplier builder which lets you specify the parameters needed to find the field.
    • fieldIn

      public static FieldSupplierBuilder fieldIn(Class<?> clazz)
      Await until a static field matches something. E.g.

       await().until(fieldIn(Service.class).ofType(int.class).andWithName("fieldName"), greaterThan(2));
       

      Here Awaitility waits until a static field with name fieldName and of the int.class in object service is greater than 2.

      Note that the field must be thread-safe in order to guarantee correct behavior.

      Parameters:
      clazz - The class that contains the static field.
      Returns:
      A field supplier builder which lets you specify the parameters needed to find the field.