Class Awaitility


  • public class Awaitility
    extends java.lang.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.
    • Constructor Summary

      Constructors 
      Constructor Description
      Awaitility()  
    • Method Summary

      All Methods Static Methods Concrete Methods 
      Modifier and Type Method Description
      static ConditionFactory await()
      Start building an await statement.
      static ConditionFactory await​(java.lang.String alias)
      Start building a named await statement.
      static ConditionFactory catchUncaughtExceptions()
      Catching uncaught exceptions in other threads.
      static void catchUncaughtExceptionsByDefault()
      Instruct Awaitility to catch uncaught exceptions from other threads by default.
      static void doNotCatchUncaughtExceptionsByDefault()
      Instruct Awaitility not to catch uncaught exceptions from other threads.
      static ConditionFactory dontCatchUncaughtExceptions()
      Don't catch uncaught exceptions in other threads.
      static FieldSupplierBuilder fieldIn​(java.lang.Class<?> clazz)
      Await until a static field matches something.
      static FieldSupplierBuilder fieldIn​(java.lang.Object object)
      Await until an instance field matches something.
      static ConditionFactory given()
      Start constructing an await statement given some settings.
      static void ignoreExceptionByDefault​(java.lang.Class<? extends java.lang.Throwable> exceptionType)
      Instruct Awaitility to ignore caught exception of the given type during condition evaluation.
      static void ignoreExceptionsByDefault()
      Instruct Awaitility to ignore caught or uncaught exceptions during condition evaluation.
      static void ignoreExceptionsByDefaultMatching​(java.util.function.Predicate<? super java.lang.Throwable> predicate)
      Instruct Awaitility to ignore caught exceptions matching the given predicate during condition evaluation.
      static void ignoreExceptionsByDefaultMatching​(org.hamcrest.Matcher<? super java.lang.Throwable> matcher)
      Instruct Awaitility to ignore caught exceptions matching the supplied matcher during condition evaluation.
      static void pollExecutorService​(java.util.concurrent.ExecutorService executorService)
      Specify the executor service whose threads will be used to evaluate the poll condition in Awaitility.
      static void pollInSameThread()
      Instructs Awaitility to execute the polling of the condition from the same as the test.
      static void pollThread​(java.util.function.Function<java.lang.Runnable,​java.lang.Thread> threadSupplier)
      Specify a thread supplier whose thread will be used to evaluate the poll condition in Awaitility.
      static void reset()
      Reset the timeout, poll interval, poll delay, uncaught exception handling to their default values:
      static void setDefaultConditionEvaluationListener​(ConditionEvaluationListener defaultConditionEvaluationListener)
      Sets the default condition evaluation listener that all await statements will use.
      static void setDefaultFailFastCondition​(java.lang.String failFastFailureReason, java.util.concurrent.Callable<java.lang.Boolean> defaultFailFastCondition)
      If the supplied Callable ever returns false, it indicates our condition will never be true, and if so fail the system immediately.
      static void setDefaultFailFastCondition​(java.lang.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.
      static void setDefaultFailFastCondition​(java.util.concurrent.Callable<java.lang.Boolean> defaultFailFastCondition)
      If the supplied Callable ever returns false, it indicates our condition will never be true, and if so fail the system immediately.
      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.
      static void setDefaultLogging()
      Sets the default logging condition evaluation listener that all await statements will use.
      static void setDefaultPollDelay​(long pollDelay, java.util.concurrent.TimeUnit unit)
      Sets the default poll delay all await statements will use.
      static void setDefaultPollDelay​(java.time.Duration pollDelay)
      Sets the default poll delay that all await statements will use.
      static void setDefaultPollInterval​(long pollInterval, java.util.concurrent.TimeUnit unit)
      Sets the default poll interval that all await statements will use.
      static void setDefaultPollInterval​(java.time.Duration pollInterval)
      Sets the default poll interval that all await statements will use.
      static void setDefaultPollInterval​(PollInterval pollInterval)
      Sets the default poll interval that all await statements will use.
      static void setDefaultTimeout​(long timeout, java.util.concurrent.TimeUnit unit)
      Sets the default timeout all await statements will use.
      static void setDefaultTimeout​(java.time.Duration defaultTimeout)
      Sets the default timeout that all await statements will use.
      static void setLogging​(java.util.function.Consumer<java.lang.String> logPrinter)
      Sets the default logging condition evaluation listener that all await statements will use.
      static void setLoggingListener​(ConditionEvaluationListener loggingListener)
      Sets the default logging condition evaluation listener that all await statements will use.
      static ConditionFactory waitAtMost​(long value, java.util.concurrent.TimeUnit unit)
      An alternative to using await() if you want to specify a timeout directly.
      static ConditionFactory waitAtMost​(java.time.Duration timeout)
      An alternative to using await() if you want to specify a timeout directly.
      static ConditionFactory with()
      Start constructing an await statement with some settings.
      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
    • Field Detail

      • DEFAULT_POLL_DELAY

        private static final java.time.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 java.time.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 Detail

      • Awaitility

        public Awaitility()
    • Method Detail

      • 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​(java.lang.Class<? extends java.lang.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​(java.util.function.Predicate<? super java.lang.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 java.lang.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​(java.util.concurrent.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​(java.util.function.Function<java.lang.Runnable,​java.lang.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​(java.lang.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​(java.time.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,
                                                  java.util.concurrent.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,
                                                  java.util.concurrent.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,
                                               java.util.concurrent.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,
                                             java.util.concurrent.TimeUnit unit)
        Sets the default timeout all await statements will use.
        Parameters:
        timeout - the timeout
        unit - the unit
      • setDefaultPollInterval

        public static void setDefaultPollInterval​(java.time.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​(java.time.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​(java.time.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.
      • setDefaultFailFastCondition

        public static void setDefaultFailFastCondition​(java.util.concurrent.Callable<java.lang.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(String, Callable)
      • setDefaultFailFastCondition

        public static void setDefaultFailFastCondition​(java.lang.String failFastFailureReason,
                                                       java.util.concurrent.Callable<java.lang.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​(java.lang.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​(java.lang.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.