org.springframework.util

## 类 Assert

- java.lang.Object
- - org.springframework.util.Assert

-     public abstract class Assert
      extends Object

  Assertion utility class that assists in validating arguments.

  Useful for identifying programmer errors early and clearly at runtime.

  For example, if the contract of a public method states it does not allow `null` arguments, `Assert` can be used to validate that contract. Doing this clearly indicates a contract violation when it occurs and protects the class's invariants.

  Typically used to validate method arguments rather than configuration properties, to check for cases that are usually programmer errors rather than configuration errors. In contrast to configuration initialization code, there is usually no point in falling back to defaults in such methods.

  This class is similar to JUnit's assertion library. If an argument value is deemed invalid, an `IllegalArgumentException` is thrown (typically). For example:

       Assert.notNull(clazz, "The class must not be null");
       Assert.isTrue(i > 0, "The value must be greater than zero");

  Mainly for internal use within the framework; consider Apache's Commons Lang for a more comprehensive suite of `String` utilities.

  从以下版本开始:
    1.1.2
  作者:
    Keith Donald, Juergen Hoeller, Sam Brannen, Colin Sampaleanu, Rob Harrop

- - ### 构造器概要

    构造器
    构造器和说明
    `Assert()`

  - ### 方法概要

    所有方法 静态方法 具体方法 已过时的方法
    限定符和类型 | 方法和说明
    --- | ---
    `static void` | `doesNotContain(String textToSearch, String substring)` 已过时。 as of 4.3.7, in favor of `doesNotContain(String, String, String)`
    `static void` | `doesNotContain(String textToSearch, String substring, String message)` Assert that the given text does not contain the given substring.
    `static void` | `doesNotContain(String textToSearch, String substring, Supplier<String> messageSupplier)` Assert that the given text does not contain the given substring.
    `static void` | `hasLength(String text)` 已过时。 as of 4.3.7, in favor of `hasLength(String, String)`
    `static void` | `hasLength(String text, String message)` Assert that the given String is not empty; that is, it must not be `null` and not the empty String.
    `static void` | `hasLength(String text, Supplier<String> messageSupplier)` Assert that the given String is not empty; that is, it must not be `null` and not the empty String.
    `static void` | `hasText(String text)` 已过时。 as of 4.3.7, in favor of `hasText(String, String)`
    `static void` | `hasText(String text, String message)` Assert that the given String contains valid text content; that is, it must not be `null` and must contain at least one non-whitespace character.
    `static void` | `hasText(String text, Supplier<String> messageSupplier)` Assert that the given String contains valid text content; that is, it must not be `null` and must contain at least one non-whitespace character.
    `static void` | `isAssignable(Class<?> superType, Class<?> subType)` Assert that `superType.isAssignableFrom(subType)` is `true`.
    `static void` | `isAssignable(Class<?> superType, Class<?> subType, String message)` Assert that `superType.isAssignableFrom(subType)` is `true`.
    `static void` | `isAssignable(Class<?> superType, Class<?> subType, Supplier<String> messageSupplier)` Assert that `superType.isAssignableFrom(subType)` is `true`.
    `static void` | `isInstanceOf(Class<?> type, Object obj)` Assert that the provided object is an instance of the provided class.
    `static void` | `isInstanceOf(Class<?> type, Object obj, String message)` Assert that the provided object is an instance of the provided class.
    `static void` | `isInstanceOf(Class<?> type, Object obj, Supplier<String> messageSupplier)` Assert that the provided object is an instance of the provided class.
    `static void` | `isNull(Object object)` 已过时。 as of 4.3.7, in favor of `isNull(Object, String)`
    `static void` | `isNull(Object object, String message)` Assert that an object is `null`.
    `static void` | `isNull(Object object, Supplier<String> messageSupplier)` Assert that an object is `null`.
    `static void` | `isTrue(boolean expression)` 已过时。 as of 4.3.7, in favor of `isTrue(boolean, String)`
    `static void` | `isTrue(boolean expression, String message)` Assert a boolean expression, throwing an `IllegalArgumentException` if the expression evaluates to `false`.
    `static void` | `isTrue(boolean expression, Supplier<String> messageSupplier)` Assert a boolean expression, throwing an `IllegalArgumentException` if the expression evaluates to `false`.
    `static void` | `noNullElements(Object[] array)` 已过时。 as of 4.3.7, in favor of `noNullElements(Object[], String)`
    `static void` | `noNullElements(Object[] array, String message)` Assert that an array contains no `null` elements.
    `static void` | `noNullElements(Object[] array, Supplier<String> messageSupplier)` Assert that an array contains no `null` elements.
    `static void` | `notEmpty(Collection<?> collection)` 已过时。 as of 4.3.7, in favor of `notEmpty(Collection, String)`
    `static void` | `notEmpty(Collection<?> collection, String message)` Assert that a collection contains elements; that is, it must not be `null` and must contain at least one element.
    `static void` | `notEmpty(Collection<?> collection, Supplier<String> messageSupplier)` Assert that a collection contains elements; that is, it must not be `null` and must contain at least one element.
    `static void` | `notEmpty(Map<?,?> map)` 已过时。 as of 4.3.7, in favor of `notEmpty(Map, String)`
    `static void` | `notEmpty(Map<?,?> map, String message)` Assert that a Map contains entries; that is, it must not be `null` and must contain at least one entry.
    `static void` | `notEmpty(Map<?,?> map, Supplier<String> messageSupplier)` Assert that a Map contains entries; that is, it must not be `null` and must contain at least one entry.
    `static void` | `notEmpty(Object[] array)` 已过时。 as of 4.3.7, in favor of `notEmpty(Object[], String)`
    `static void` | `notEmpty(Object[] array, String message)` Assert that an array contains elements; that is, it must not be `null` and must contain at least one element.
    `static void` | `notEmpty(Object[] array, Supplier<String> messageSupplier)` Assert that an array contains elements; that is, it must not be `null` and must contain at least one element.
    `static void` | `notNull(Object object)` 已过时。 as of 4.3.7, in favor of `notNull(Object, String)`
    `static void` | `notNull(Object object, String message)` Assert that an object is not `null`.
    `static void` | `notNull(Object object, Supplier<String> messageSupplier)` Assert that an object is not `null`.
    `static void` | `state(boolean expression)` 已过时。 as of 4.3.7, in favor of `state(boolean, String)`
    `static void` | `state(boolean expression, String message)` Assert a boolean expression, throwing an `IllegalStateException` if the expression evaluates to `false`.
    `static void` | `state(boolean expression, Supplier<String> messageSupplier)` Assert a boolean expression, throwing an `IllegalStateException` if the expression evaluates to `false`.

    - ### 从类继承的方法 java.lang.Object

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

- - ### 构造器详细资料

    - #### Assert

          public Assert()

  - ### 方法详细资料

    - #### state

          public static void state(boolean expression,
                                   String message)

      Assert a boolean expression, throwing an `IllegalStateException` if the expression evaluates to `false`.

      Call `isTrue(boolean, java.lang.String)` if you wish to throw an `IllegalArgumentException` on an assertion failure.

          Assert.state(id == null, "The id property must not already be initialized");

      参数:
        `expression` - a boolean expression
        `message` - the exception message to use if the assertion fails
      抛出:
        `IllegalStateException` - if `expression` is `false`

    - #### state

          public static void state(boolean expression,
                                   Supplier<String> messageSupplier)

      Assert a boolean expression, throwing an `IllegalStateException` if the expression evaluates to `false`.

      Call `isTrue(boolean, java.lang.String)` if you wish to throw an `IllegalArgumentException` on an assertion failure.

           Assert.state(id == null,
               () -> "ID for " + entity.getName() + " must not already be initialized");

      参数:
        `expression` - a boolean expression
        `messageSupplier` - a supplier for the exception message to use if the assertion fails
      抛出:
        `IllegalStateException` - if `expression` is `false`
      从以下版本开始:
        5.0

    - #### state

          @Deprecated
          public static void state(boolean expression)

      已过时。 as of 4.3.7, in favor of `state(boolean, String)`

    - #### isTrue

          public static void isTrue(boolean expression,
                                    String message)

      Assert a boolean expression, throwing an `IllegalArgumentException` if the expression evaluates to `false`.

          Assert.isTrue(i > 0, "The value must be greater than zero");

      参数:
        `expression` - a boolean expression
        `message` - the exception message to use if the assertion fails
      抛出:
        `IllegalArgumentException` - if `expression` is `false`

    - #### isTrue

          public static void isTrue(boolean expression,
                                    Supplier<String> messageSupplier)

      Assert a boolean expression, throwing an `IllegalArgumentException` if the expression evaluates to `false`.

           Assert.isTrue(i > 0, () -> "The value '" + i + "' must be greater than zero");

      参数:
        `expression` - a boolean expression
        `messageSupplier` - a supplier for the exception message to use if the assertion fails
      抛出:
        `IllegalArgumentException` - if `expression` is `false`
      从以下版本开始:
        5.0

    - #### isTrue

          @Deprecated
          public static void isTrue(boolean expression)

      已过时。 as of 4.3.7, in favor of `isTrue(boolean, String)`

    - #### isNull

          public static void isNull(@Nullable
                                    Object object,
                                    String message)

      Assert that an object is `null`.

          Assert.isNull(value, "The value must be null");

      参数:
        `object` - the object to check
        `message` - the exception message to use if the assertion fails
      抛出:
        `IllegalArgumentException` - if the object is not `null`

    - #### isNull

          public static void isNull(@Nullable
                                    Object object,
                                    Supplier<String> messageSupplier)

      Assert that an object is `null`.

           Assert.isNull(value, () -> "The value '" + value + "' must be null");

      参数:
        `object` - the object to check
        `messageSupplier` - a supplier for the exception message to use if the assertion fails
      抛出:
        `IllegalArgumentException` - if the object is not `null`
      从以下版本开始:
        5.0

    - #### isNull

          @Deprecated
          public static void isNull(@Nullable
                                                 Object object)

      已过时。 as of 4.3.7, in favor of `isNull(Object, String)`

    - #### notNull

          public static void notNull(@Nullable
                                     Object object,
                                     String message)

      Assert that an object is not `null`.

          Assert.notNull(clazz, "The class must not be null");

      参数:
        `object` - the object to check
        `message` - the exception message to use if the assertion fails
      抛出:
        `IllegalArgumentException` - if the object is `null`

    - #### notNull

          public static void notNull(@Nullable
                                     Object object,
                                     Supplier<String> messageSupplier)

      Assert that an object is not `null`.

           Assert.notNull(clazz, () -> "The class '" + clazz.getName() + "' must not be null");

      参数:
        `object` - the object to check
        `messageSupplier` - a supplier for the exception message to use if the assertion fails
      抛出:
        `IllegalArgumentException` - if the object is `null`
      从以下版本开始:
        5.0

    - #### notNull

          @Deprecated
          public static void notNull(@Nullable
                                                  Object object)

      已过时。 as of 4.3.7, in favor of `notNull(Object, String)`

    - #### hasLength

          public static void hasLength(@Nullable
                                       String text,
                                       String message)

      Assert that the given String is not empty; that is, it must not be `null` and not the empty String.

          Assert.hasLength(name, "Name must not be empty");

      参数:
        `text` - the String to check
        `message` - the exception message to use if the assertion fails
      抛出:
        `IllegalArgumentException` - if the text is empty
      另请参阅:
        `StringUtils.hasLength(java.lang.CharSequence)`

    - #### hasLength

          public static void hasLength(@Nullable
                                       String text,
                                       Supplier<String> messageSupplier)

      Assert that the given String is not empty; that is, it must not be `null` and not the empty String.

           Assert.hasLength(name, () -> "Name for account '" + account.getId() + "' must not be empty");

      参数:
        `text` - the String to check
        `messageSupplier` - a supplier for the exception message to use if the assertion fails
      抛出:
        `IllegalArgumentException` - if the text is empty
      从以下版本开始:
        5.0
      另请参阅:
        `StringUtils.hasLength(java.lang.CharSequence)`

    - #### hasLength

          @Deprecated
          public static void hasLength(@Nullable
                                                    String text)

      已过时。 as of 4.3.7, in favor of `hasLength(String, String)`

    - #### hasText

          public static void hasText(@Nullable
                                     String text,
                                     String message)

      Assert that the given String contains valid text content; that is, it must not be `null` and must contain at least one non-whitespace character.

          Assert.hasText(name, "'name' must not be empty");

      参数:
        `text` - the String to check
        `message` - the exception message to use if the assertion fails
      抛出:
        `IllegalArgumentException` - if the text does not contain valid text content
      另请参阅:
        `StringUtils.hasText(java.lang.CharSequence)`

    - #### hasText

          public static void hasText(@Nullable
                                     String text,
                                     Supplier<String> messageSupplier)

      Assert that the given String contains valid text content; that is, it must not be `null` and must contain at least one non-whitespace character.

           Assert.hasText(name, () -> "Name for account '" + account.getId() + "' must not be empty");

      参数:
        `text` - the String to check
        `messageSupplier` - a supplier for the exception message to use if the assertion fails
      抛出:
        `IllegalArgumentException` - if the text does not contain valid text content
      从以下版本开始:
        5.0
      另请参阅:
        `StringUtils.hasText(java.lang.CharSequence)`

    - #### hasText

          @Deprecated
          public static void hasText(@Nullable
                                                  String text)

      已过时。 as of 4.3.7, in favor of `hasText(String, String)`

    - #### doesNotContain

          public static void doesNotContain(@Nullable
                                            String textToSearch,
                                            String substring,
                                            String message)

      Assert that the given text does not contain the given substring.

          Assert.doesNotContain(name, "rod", "Name must not contain 'rod'");

      参数:
        `textToSearch` - the text to search
        `substring` - the substring to find within the text
        `message` - the exception message to use if the assertion fails
      抛出:
        `IllegalArgumentException` - if the text contains the substring

    - #### doesNotContain

          public static void doesNotContain(@Nullable
                                            String textToSearch,
                                            String substring,
                                            Supplier<String> messageSupplier)

      Assert that the given text does not contain the given substring.

           Assert.doesNotContain(name, forbidden, () -> "Name must not contain '" + forbidden + "'");

      参数:
        `textToSearch` - the text to search
        `substring` - the substring to find within the text
        `messageSupplier` - a supplier for the exception message to use if the assertion fails
      抛出:
        `IllegalArgumentException` - if the text contains the substring
      从以下版本开始:
        5.0

    - #### doesNotContain

          @Deprecated
          public static void doesNotContain(@Nullable
                                                         String textToSearch,
                                                         String substring)

      已过时。 as of 4.3.7, in favor of `doesNotContain(String, String, String)`

    - #### notEmpty

          public static void notEmpty(@Nullable
                                      Object[] array,
                                      String message)

      Assert that an array contains elements; that is, it must not be `null` and must contain at least one element.

          Assert.notEmpty(array, "The array must contain elements");

      参数:
        `array` - the array to check
        `message` - the exception message to use if the assertion fails
      抛出:
        `IllegalArgumentException` - if the object array is `null` or contains no elements

    - #### notEmpty

          public static void notEmpty(@Nullable
                                      Object[] array,
                                      Supplier<String> messageSupplier)

      Assert that an array contains elements; that is, it must not be `null` and must contain at least one element.

           Assert.notEmpty(array, () -> "The " + arrayType + " array must contain elements");

      参数:
        `array` - the array to check
        `messageSupplier` - a supplier for the exception message to use if the assertion fails
      抛出:
        `IllegalArgumentException` - if the object array is `null` or contains no elements
      从以下版本开始:
        5.0

    - #### notEmpty

          @Deprecated
          public static void notEmpty(@Nullable
                                                   Object[] array)

      已过时。 as of 4.3.7, in favor of `notEmpty(Object[], String)`

    - #### noNullElements

          public static void noNullElements(@Nullable
                                            Object[] array,
                                            String message)

      Assert that an array contains no `null` elements.

      Note: Does not complain if the array is empty!

          Assert.noNullElements(array, "The array must contain non-null elements");

      参数:
        `array` - the array to check
        `message` - the exception message to use if the assertion fails
      抛出:
        `IllegalArgumentException` - if the object array contains a `null` element

    - #### noNullElements

          public static void noNullElements(@Nullable
                                            Object[] array,
                                            Supplier<String> messageSupplier)

      Assert that an array contains no `null` elements.

      Note: Does not complain if the array is empty!

           Assert.noNullElements(array, () -> "The " + arrayType + " array must contain non-null elements");

      参数:
        `array` - the array to check
        `messageSupplier` - a supplier for the exception message to use if the assertion fails
      抛出:
        `IllegalArgumentException` - if the object array contains a `null` element
      从以下版本开始:
        5.0

    - #### noNullElements

          @Deprecated
          public static void noNullElements(@Nullable
                                                         Object[] array)

      已过时。 as of 4.3.7, in favor of `noNullElements(Object[], String)`

    - #### notEmpty

          public static void notEmpty(@Nullable
                                      Collection<?> collection,
                                      String message)

      Assert that a collection contains elements; that is, it must not be `null` and must contain at least one element.

          Assert.notEmpty(collection, "Collection must contain elements");

      参数:
        `collection` - the collection to check
        `message` - the exception message to use if the assertion fails
      抛出:
        `IllegalArgumentException` - if the collection is `null` or contains no elements

    - #### notEmpty

          public static void notEmpty(@Nullable
                                      Collection<?> collection,
                                      Supplier<String> messageSupplier)

      Assert that a collection contains elements; that is, it must not be `null` and must contain at least one element.

           Assert.notEmpty(collection, () -> "The " + collectionType + " collection must contain elements");

      参数:
        `collection` - the collection to check
        `messageSupplier` - a supplier for the exception message to use if the assertion fails
      抛出:
        `IllegalArgumentException` - if the collection is `null` or contains no elements
      从以下版本开始:
        5.0

    - #### notEmpty

          @Deprecated
          public static void notEmpty(@Nullable
                                                   Collection<?> collection)

      已过时。 as of 4.3.7, in favor of `notEmpty(Collection, String)`

    - #### notEmpty

          public static void notEmpty(@Nullable
                                      Map<?,?> map,
                                      String message)

      Assert that a Map contains entries; that is, it must not be `null` and must contain at least one entry.

          Assert.notEmpty(map, "Map must contain entries");

      参数:
        `map` - the map to check
        `message` - the exception message to use if the assertion fails
      抛出:
        `IllegalArgumentException` - if the map is `null` or contains no entries

    - #### notEmpty

          public static void notEmpty(@Nullable
                                      Map<?,?> map,
                                      Supplier<String> messageSupplier)

      Assert that a Map contains entries; that is, it must not be `null` and must contain at least one entry.

           Assert.notEmpty(map, () -> "The " + mapType + " map must contain entries");

      参数:
        `map` - the map to check
        `messageSupplier` - a supplier for the exception message to use if the assertion fails
      抛出:
        `IllegalArgumentException` - if the map is `null` or contains no entries
      从以下版本开始:
        5.0

    - #### notEmpty

          @Deprecated
          public static void notEmpty(@Nullable
                                                   Map<?,?> map)

      已过时。 as of 4.3.7, in favor of `notEmpty(Map, String)`

    - #### isInstanceOf

          public static void isInstanceOf(Class<?> type,
                                          @Nullable
                                          Object obj,
                                          String message)

      Assert that the provided object is an instance of the provided class.

          Assert.instanceOf(Foo.class, foo, "Foo expected");

      参数:
        `type` - the type to check against
        `obj` - the object to check
        `message` - a message which will be prepended to provide further context. If it is empty or ends in ":" or ";" or "," or ".", a full exception message will be appended. If it ends in a space, the name of the offending object's type will be appended. In any other case, a ":" with a space and the name of the offending object's type will be appended.
      抛出:
        `IllegalArgumentException` - if the object is not an instance of type

    - #### isInstanceOf

          public static void isInstanceOf(Class<?> type,
                                          @Nullable
                                          Object obj,
                                          Supplier<String> messageSupplier)

      Assert that the provided object is an instance of the provided class.

           Assert.instanceOf(Foo.class, foo, () -> "Processing " + Foo.class.getSimpleName() + ":");

      参数:
        `type` - the type to check against
        `obj` - the object to check
        `messageSupplier` - a supplier for the exception message to use if the assertion fails. See `isInstanceOf(Class, Object, String)` for details.
      抛出:
        `IllegalArgumentException` - if the object is not an instance of type
      从以下版本开始:
        5.0

    - #### isInstanceOf

          public static void isInstanceOf(Class<?> type,
                                          @Nullable
                                          Object obj)

      Assert that the provided object is an instance of the provided class.

          Assert.instanceOf(Foo.class, foo);

      参数:
        `type` - the type to check against
        `obj` - the object to check
      抛出:
        `IllegalArgumentException` - if the object is not an instance of type

    - #### isAssignable

          public static void isAssignable(Class<?> superType,
                                          @Nullable
                                          Class<?> subType,
                                          String message)

      Assert that `superType.isAssignableFrom(subType)` is `true`.

          Assert.isAssignable(Number.class, myClass, "Number expected");

      参数:
        `superType` - the super type to check against
        `subType` - the sub type to check
        `message` - a message which will be prepended to provide further context. If it is empty or ends in ":" or ";" or "," or ".", a full exception message will be appended. If it ends in a space, the name of the offending sub type will be appended. In any other case, a ":" with a space and the name of the offending sub type will be appended.
      抛出:
        `IllegalArgumentException` - if the classes are not assignable

    - #### isAssignable

          public static void isAssignable(Class<?> superType,
                                          @Nullable
                                          Class<?> subType,
                                          Supplier<String> messageSupplier)

      Assert that `superType.isAssignableFrom(subType)` is `true`.

           Assert.isAssignable(Number.class, myClass, () -> "Processing " + myAttributeName + ":");

      参数:
        `superType` - the super type to check against
        `subType` - the sub type to check
        `messageSupplier` - a supplier for the exception message to use if the assertion fails. See `isAssignable(Class, Class, String)` for details.
      抛出:
        `IllegalArgumentException` - if the classes are not assignable
      从以下版本开始:
        5.0

    - #### isAssignable

          public static void isAssignable(Class<?> superType,
                                          Class<?> subType)

      Assert that `superType.isAssignableFrom(subType)` is `true`.

          Assert.isAssignable(Number.class, myClass);

      参数:
        `superType` - the super type to check
        `subType` - the sub type to check
      抛出:
        `IllegalArgumentException` - if the classes are not assignable