java.lang.Object | |
↳ | org.springframework.util.Assert |
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 config initialization code, there is usally 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 Jakarta's Commons Lang >= 2.0 for a more comprehensive suite of assertion utilities.
Public Constructors | |||||||||||
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Public Methods | |||||||||||
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Assert that the given text does not contain the given substring.
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Assert that the given text does not contain the given substring.
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Assert that the given String is not empty; that is,
it must not be
null and not the empty String. | |||||||||||
Assert that the given String is not empty; that is,
it must not be
null and not the empty String. | |||||||||||
Assert that the given String has valid text content; that is, it must not
be
null and must contain at least one non-whitespace character. | |||||||||||
Assert that the given String has valid text content; that is, it must not
be
null and must contain at least one non-whitespace character. | |||||||||||
Assert that
superType.isAssignableFrom(subType) is true . | |||||||||||
Assert that
superType.isAssignableFrom(subType) is true . | |||||||||||
Assert that the provided object is an instance of the provided class.
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Assert that the provided object is an instance of the provided class.
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Assert that an object is
null . | |||||||||||
Assert that an object is
null . | |||||||||||
Assert a boolean expression, throwing
IllegalArgumentException
if the test result is false . | |||||||||||
Assert a boolean expression, throwing
IllegalArgumentException
if the test result is false . | |||||||||||
Assert that an array has no null elements.
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Assert that an array has no null elements.
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Assert that an array has elements; that is, it must not be
null and must have at least one element. | |||||||||||
Assert that a Map has entries; that is, it must not be
null
and must have at least one entry. | |||||||||||
Assert that an array has elements; that is, it must not be
null and must have at least one element. | |||||||||||
Assert that a collection has elements; that is, it must not be
null and must have at least one element. | |||||||||||
Assert that a collection has elements; that is, it must not be
null and must have at least one element. | |||||||||||
Assert that a Map has entries; that is, it must not be
null
and must have at least one entry. | |||||||||||
Assert that an object is not
null . | |||||||||||
Assert that an object is not
null . | |||||||||||
Assert a boolean expression, throwing
IllegalStateException
if the test result is false . | |||||||||||
Assert a boolean expression, throwing
IllegalStateException
if the test result is false . |
[Expand]
Inherited Methods | |||||||||||
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From class
java.lang.Object
|
Assert that the given text does not contain the given substring.
Assert.doesNotContain(name, "rod", "Name must not contain 'rod'");
textToSearch | the text to search |
---|---|
substring | the substring to find within the text |
message | the exception message to use if the assertion fails |
Assert that the given text does not contain the given substring.
Assert.doesNotContain(name, "rod");
textToSearch | the text to search |
---|---|
substring | the substring to find within the text |
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");
text | the String to check |
---|---|
message | the exception message to use if the assertion fails |
Assert that the given String is not empty; that is,
it must not be null
and not the empty String.
Assert.hasLength(name);
text | the String to check |
---|
Assert that the given String has 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");
text | the String to check |
---|---|
message | the exception message to use if the assertion fails |
Assert that the given String has 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");
text | the String to check |
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Assert that superType.isAssignableFrom(subType)
is true
.
Assert.isAssignable(Number.class, myClass);
superType | the super type to check against |
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subType | the sub type to check |
message | a message which will be prepended to the message produced by the function itself, and which may be used to provide context. It should normally end in a ": " or ". " so that the function generate message looks ok when prepended to it. |
IllegalArgumentException | if the classes are not assignable |
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Assert that superType.isAssignableFrom(subType)
is true
.
Assert.isAssignable(Number.class, myClass);
superType | the super type to check |
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subType | the sub type to check |
IllegalArgumentException | if the classes are not assignable |
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Assert that the provided object is an instance of the provided class.
Assert.instanceOf(Foo.class, foo);
clazz | the required class |
---|---|
obj | the object to check |
IllegalArgumentException | if the object is not an instance of clazz |
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Assert that the provided object is an instance of the provided class.
Assert.instanceOf(Foo.class, foo);
type | the type to check against |
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obj | the object to check |
message | a message which will be prepended to the message produced by the function itself, and which may be used to provide context. It should normally end in a ": " or ". " so that the function generate message looks ok when prepended to it. |
IllegalArgumentException | if the object is not an instance of clazz |
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Assert that an object is null
.
Assert.isNull(value, "The value must be null");
object | the object to check |
---|---|
message | the exception message to use if the assertion fails |
IllegalArgumentException | if the object is not null
|
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Assert that an object is null
.
Assert.isNull(value);
object | the object to check |
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IllegalArgumentException | if the object is not null
|
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Assert a boolean expression, throwing IllegalArgumentException
if the test result is false
.
Assert.isTrue(i > 0, "The value must be greater than zero");
expression | a boolean expression |
---|---|
message | the exception message to use if the assertion fails |
IllegalArgumentException | if expression is false
|
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Assert a boolean expression, throwing IllegalArgumentException
if the test result is false
.
Assert.isTrue(i > 0);
expression | a boolean expression |
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IllegalArgumentException | if expression is false
|
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Assert that an array has no null elements. Note: Does not complain if the array is empty!
Assert.noNullElements(array, "The array must have non-null elements");
array | the array to check |
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message | the exception message to use if the assertion fails |
IllegalArgumentException | if the object array contains a null element
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Assert that an array has no null elements. Note: Does not complain if the array is empty!
Assert.noNullElements(array);
array | the array to check |
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IllegalArgumentException | if the object array contains a null element
|
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Assert that an array has elements; that is, it must not be
null
and must have at least one element.
Assert.notEmpty(array);
array | the array to check |
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IllegalArgumentException | if the object array is null or has no elements
|
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Assert that a Map has entries; that is, it must not be null
and must have at least one entry.
Assert.notEmpty(map);
map | the map to check |
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IllegalArgumentException | if the map is null or has no entries
|
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Assert that an array has elements; that is, it must not be
null
and must have at least one element.
Assert.notEmpty(array, "The array must have elements");
array | the array to check |
---|---|
message | the exception message to use if the assertion fails |
IllegalArgumentException | if the object array is null or has no elements
|
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Assert that a collection has elements; that is, it must not be
null
and must have at least one element.
Assert.notEmpty(collection, "Collection must have elements");
collection | the collection to check |
---|
IllegalArgumentException | if the collection is null or has no elements
|
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Assert that a collection has elements; that is, it must not be
null
and must have at least one element.
Assert.notEmpty(collection, "Collection must have elements");
collection | the collection to check |
---|---|
message | the exception message to use if the assertion fails |
IllegalArgumentException | if the collection is null or has no elements
|
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Assert that a Map has entries; that is, it must not be null
and must have at least one entry.
Assert.notEmpty(map, "Map must have entries");
map | the map to check |
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message | the exception message to use if the assertion fails |
IllegalArgumentException | if the map is null or has no entries
|
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Assert that an object is not null
.
Assert.notNull(clazz);
object | the object to check |
---|
IllegalArgumentException | if the object is null
|
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Assert that an object is not null
.
Assert.notNull(clazz, "The class must not be null");
object | the object to check |
---|---|
message | the exception message to use if the assertion fails |
IllegalArgumentException | if the object is null
|
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Assert a boolean expression, throwing IllegalStateException
if the test result is false
.
Call isTrue(boolean)
if you wish to
throw IllegalArgumentException
on an assertion failure.
Assert.state(id == null);
expression | a boolean expression |
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IllegalStateException | if the supplied expression is false
|
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Assert a boolean expression, throwing IllegalStateException
if the test result is false
. Call isTrue if you wish to
throw IllegalArgumentException on an assertion failure.
Assert.state(id == null, "The id property must not already be initialized");
expression | a boolean expression |
---|---|
message | the exception message to use if the assertion fails |
IllegalStateException | if expression is false
|
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