Package org.junit.platform.commons.util

Class Preconditions

java.lang.Object
org.junit.platform.commons.util.Preconditions
@API(status=INTERNAL,
     since="1.0")
public final class Preconditions
extends java.lang.Object
Collection of utilities for asserting preconditions for method and constructor arguments.

Each method in this class throws a PreconditionViolationException if the precondition is violated.

DISCLAIMER

These utilities are intended solely for usage within the JUnit framework itself. Any usage by external parties is not supported. Use at your own risk!

Since:
1.0

  • Method Summary

    Modifier and Type Method Description
    static void condition​(boolean predicate, java.lang.String message)
    Assert that the supplied predicate is true.
    static void condition​(boolean predicate, java.util.function.Supplier<java.lang.String> messageSupplier)
    Assert that the supplied predicate is true.
    static <T> T[] containsNoNullElements​(T[] array, java.lang.String message)
    Assert that the supplied array contains no null elements.
    static <T> T[] containsNoNullElements​(T[] array, java.util.function.Supplier<java.lang.String> messageSupplier)
    Assert that the supplied array contains no null elements.
    static <T extends java.util.Collection<?>>
    T    		 containsNoNullElements​(T collection, java.lang.String message)
    Assert that the supplied collection contains no null elements.
    static <T extends java.util.Collection<?>>
    T    		 containsNoNullElements​(T collection, java.util.function.Supplier<java.lang.String> messageSupplier)
    Assert that the supplied collection contains no null elements.
    static java.lang.String notBlank​(java.lang.String str, java.lang.String message)
    Assert that the supplied String is not blank.
    static java.lang.String notBlank​(java.lang.String str, java.util.function.Supplier<java.lang.String> messageSupplier)
    Assert that the supplied String is not blank.
    static <T> T[] notEmpty​(T[] array, java.lang.String message)
    Assert that the supplied array is neither null nor empty.
    static <T> T[] notEmpty​(T[] array, java.util.function.Supplier<java.lang.String> messageSupplier)
    Assert that the supplied array is neither null nor empty.
    static <T extends java.util.Collection<?>>
    T    		 notEmpty​(T collection, java.lang.String message)
    Assert that the supplied Collection is neither null nor empty.
    static <T extends java.util.Collection<?>>
    T    		 notEmpty​(T collection, java.util.function.Supplier<java.lang.String> messageSupplier)
    Assert that the supplied Collection is neither null nor empty.
    static <T> T notNull​(T object, java.lang.String message)
    Assert that the supplied Object is not null.
    static <T> T notNull​(T object, java.util.function.Supplier<java.lang.String> messageSupplier)
    Assert that the supplied Object is not null.

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Method Details

    • notNull

      public static <T> T notNull​(T object, java.lang.String message) throws PreconditionViolationException
      Assert that the supplied Object is not null.
      Parameters:
      object - the object to check
      message - precondition violation message
      Returns:
      the supplied object as a convenience
      Throws:
      PreconditionViolationException - if the supplied object is null
      See Also:
      notNull(Object, Supplier)

    • notNull

      public static <T> T notNull​(T object, java.util.function.Supplier<java.lang.String> messageSupplier) throws PreconditionViolationException
      Assert that the supplied Object is not null.
      Parameters:
      object - the object to check
      messageSupplier - precondition violation message supplier
      Returns:
      the supplied object as a convenience
      Throws:
      PreconditionViolationException - if the supplied object is null
      See Also:
      condition(boolean, Supplier)

    • notEmpty

      public static <T> T[] notEmpty​(T[] array, java.lang.String message) throws PreconditionViolationException
      Assert that the supplied array is neither null nor empty.

      WARNING: this method does NOT check if the supplied array contains any null elements.

      Parameters:
      array - the array to check
      message - precondition violation message
      Returns:
      the supplied array as a convenience
      Throws:
      PreconditionViolationException - if the supplied array is null or empty
      See Also:
      containsNoNullElements(Object[], String), condition(boolean, String)

    • notEmpty

      public static <T> T[] notEmpty​(T[] array, java.util.function.Supplier<java.lang.String> messageSupplier) throws PreconditionViolationException
      Assert that the supplied array is neither null nor empty.

      WARNING: this method does NOT check if the supplied array contains any null elements.

      Parameters:
      array - the array to check
      messageSupplier - precondition violation message supplier
      Returns:
      the supplied array as a convenience
      Throws:
      PreconditionViolationException - if the supplied array is null or empty
      See Also:
      containsNoNullElements(Object[], String), condition(boolean, String)

    • notEmpty

      public static <T extends java.util.Collection<?>> T notEmpty​(T collection, java.lang.String message) throws PreconditionViolationException
      Assert that the supplied Collection is neither null nor empty.

      WARNING: this method does NOT check if the supplied collection contains any null elements.

      Parameters:
      collection - the collection to check
      message - precondition violation message
      Returns:
      the supplied collection as a convenience
      Throws:
      PreconditionViolationException - if the supplied collection is null or empty
      See Also:
      containsNoNullElements(Collection, String), condition(boolean, String)

    • notEmpty

      public static <T extends java.util.Collection<?>> T notEmpty​(T collection, java.util.function.Supplier<java.lang.String> messageSupplier) throws PreconditionViolationException
      Assert that the supplied Collection is neither null nor empty.

      WARNING: this method does NOT check if the supplied collection contains any null elements.

      Parameters:
      collection - the collection to check
      messageSupplier - precondition violation message supplier
      Returns:
      the supplied collection as a convenience
      Throws:
      PreconditionViolationException - if the supplied collection is null or empty
      See Also:
      containsNoNullElements(Collection, String), condition(boolean, String)

    • containsNoNullElements

      public static <T> T[] containsNoNullElements​(T[] array, java.lang.String message) throws PreconditionViolationException
      Assert that the supplied array contains no null elements.

      WARNING: this method does NOT check if the supplied array is null or empty.

      Parameters:
      array - the array to check
      message - precondition violation message
      Returns:
      the supplied array as a convenience
      Throws:
      PreconditionViolationException - if the supplied array contains any null elements
      See Also:
      notNull(Object, String)

    • containsNoNullElements

      public static <T> T[] containsNoNullElements​(T[] array, java.util.function.Supplier<java.lang.String> messageSupplier) throws PreconditionViolationException
      Assert that the supplied array contains no null elements.

      WARNING: this method does NOT check if the supplied array is null or empty.

      Parameters:
      array - the array to check
      messageSupplier - precondition violation message supplier
      Returns:
      the supplied array as a convenience
      Throws:
      PreconditionViolationException - if the supplied array contains any null elements
      See Also:
      notNull(Object, String)

    • containsNoNullElements

      public static <T extends java.util.Collection<?>> T containsNoNullElements​(T collection, java.lang.String message) throws PreconditionViolationException
      Assert that the supplied collection contains no null elements.

      WARNING: this method does NOT check if the supplied collection is null or empty.

      Parameters:
      collection - the collection to check
      message - precondition violation message
      Returns:
      the supplied collection as a convenience
      Throws:
      PreconditionViolationException - if the supplied collection contains any null elements
      See Also:
      notNull(Object, String)

    • containsNoNullElements

      public static <T extends java.util.Collection<?>> T containsNoNullElements​(T collection, java.util.function.Supplier<java.lang.String> messageSupplier) throws PreconditionViolationException
      Assert that the supplied collection contains no null elements.

      WARNING: this method does NOT check if the supplied collection is null or empty.

      Parameters:
      collection - the collection to check
      messageSupplier - precondition violation message supplier
      Returns:
      the supplied collection as a convenience
      Throws:
      PreconditionViolationException - if the supplied collection contains any null elements
      See Also:
      notNull(Object, String)

    • notBlank

      public static java.lang.String notBlank​(java.lang.String str, java.lang.String message) throws PreconditionViolationException
      Assert that the supplied String is not blank.

      A String is blank if it is null or consists only of whitespace characters.

      Parameters:
      str - the string to check
      message - precondition violation message
      Returns:
      the supplied string as a convenience
      Throws:
      PreconditionViolationException - if the supplied string is blank
      See Also:
      notBlank(String, Supplier)

    • notBlank

      public static java.lang.String notBlank​(java.lang.String str, java.util.function.Supplier<java.lang.String> messageSupplier) throws PreconditionViolationException
      Assert that the supplied String is not blank.

      A String is blank if it is null or consists only of whitespace characters.

      Parameters:
      str - the string to check
      messageSupplier - precondition violation message supplier
      Returns:
      the supplied string as a convenience
      Throws:
      PreconditionViolationException - if the supplied string is blank
      See Also:
      StringUtils.isNotBlank(String), condition(boolean, Supplier)

    • condition

      public static void condition​(boolean predicate, java.lang.String message) throws PreconditionViolationException
      Assert that the supplied predicate is true.
      Parameters:
      predicate - the predicate to check
      message - precondition violation message
      Throws:
      PreconditionViolationException - if the predicate is false
      See Also:
      condition(boolean, Supplier)

    • condition

      public static void condition​(boolean predicate, java.util.function.Supplier<java.lang.String> messageSupplier) throws PreconditionViolationException
      Assert that the supplied predicate is true.
      Parameters:
      predicate - the predicate to check
      messageSupplier - precondition violation message supplier
      Throws:
      PreconditionViolationException - if the predicate is false