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; for a more comprehensive suite of assertion utilities consider
org.apache.commons.lang3.Validate
from Apache Commons Lang, Google Guava's Preconditions, or similar third-party libraries.- 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 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 修饰符和类型 方法 说明 static void
doesNotContain(String textToSearch, String substring)
已过时。as of 4.3.7, in favor ofdoesNotContain(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 ofhasLength(String, String)
static void
hasLength(String text, String message)
Assert that the given String is not empty; that is, it must not benull
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 benull
and not the empty String.static void
hasText(String text)
已过时。as of 4.3.7, in favor ofhasText(String, String)
static void
hasText(String text, String message)
Assert that the given String contains valid text content; that is, it must not benull
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 benull
and must contain at least one non-whitespace character.static void
isAssignable(Class<?> superType, Class<?> subType)
Assert thatsuperType.isAssignableFrom(subType)
istrue
.static void
isAssignable(Class<?> superType, Class<?> subType, String message)
Assert thatsuperType.isAssignableFrom(subType)
istrue
.static void
isAssignable(Class<?> superType, Class<?> subType, Supplier<String> messageSupplier)
Assert thatsuperType.isAssignableFrom(subType)
istrue
.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 ofisNull(Object, String)
static void
isNull(Object object, String message)
Assert that an object isnull
.static void
isNull(Object object, Supplier<String> messageSupplier)
Assert that an object isnull
.static void
isTrue(boolean expression)
已过时。as of 4.3.7, in favor ofisTrue(boolean, String)
static void
isTrue(boolean expression, String message)
Assert a boolean expression, throwing anIllegalArgumentException
if the expression evaluates tofalse
.static void
isTrue(boolean expression, Supplier<String> messageSupplier)
Assert a boolean expression, throwing anIllegalArgumentException
if the expression evaluates tofalse
.static void
noNullElements(Object[] array)
已过时。as of 4.3.7, in favor ofnoNullElements(Object[], String)
static void
noNullElements(Object[] array, String message)
Assert that an array contains nonull
elements.static void
noNullElements(Object[] array, Supplier<String> messageSupplier)
Assert that an array contains nonull
elements.static void
noNullElements(Collection<?> collection, String message)
Assert that a collection contains nonull
elements.static void
noNullElements(Collection<?> collection, Supplier<String> messageSupplier)
Assert that a collection contains nonull
elements.static void
notEmpty(Object[] array)
已过时。as of 4.3.7, in favor ofnotEmpty(Object[], String)
static void
notEmpty(Object[] array, String message)
Assert that an array contains elements; that is, it must not benull
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 benull
and must contain at least one element.static void
notEmpty(Collection<?> collection)
已过时。as of 4.3.7, in favor ofnotEmpty(Collection, String)
static void
notEmpty(Collection<?> collection, String message)
Assert that a collection contains elements; that is, it must not benull
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 benull
and must contain at least one element.static void
notEmpty(Map<?,?> map)
已过时。as of 4.3.7, in favor ofnotEmpty(Map, String)
static void
notEmpty(Map<?,?> map, String message)
Assert that a Map contains entries; that is, it must not benull
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 benull
and must contain at least one entry.static void
notNull(Object object)
已过时。as of 4.3.7, in favor ofnotNull(Object, String)
static void
notNull(Object object, String message)
Assert that an object is notnull
.static void
notNull(Object object, Supplier<String> messageSupplier)
Assert that an object is notnull
.static void
state(boolean expression)
已过时。as of 4.3.7, in favor ofstate(boolean, String)
static void
state(boolean expression, String message)
Assert a boolean expression, throwing anIllegalStateException
if the expression evaluates tofalse
.static void
state(boolean expression, Supplier<String> messageSupplier)
Assert a boolean expression, throwing anIllegalStateException
if the expression evaluates tofalse
.
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 anIllegalStateException
if the expression evaluates tofalse
.Call
isTrue(boolean, java.lang.String)
if you wish to throw anIllegalArgumentException
on an assertion failure.Assert.state(id == null, "The id property must not already be initialized");
- 参数:
expression
- a boolean expressionmessage
- the exception message to use if the assertion fails- 抛出:
IllegalStateException
- ifexpression
isfalse
state
public static void state(boolean expression, Supplier<String> messageSupplier)
Assert a boolean expression, throwing anIllegalStateException
if the expression evaluates tofalse
.Call
isTrue(boolean, java.lang.String)
if you wish to throw anIllegalArgumentException
on an assertion failure.Assert.state(entity.getId() == null, () -> "ID for entity " + entity.getName() + " must not already be initialized");
- 参数:
expression
- a boolean expressionmessageSupplier
- a supplier for the exception message to use if the assertion fails- 抛出:
IllegalStateException
- ifexpression
isfalse
- 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 ofstate(boolean, String)
Assert a boolean expression, throwing anIllegalStateException
if the expression evaluates tofalse
.
isTrue
public static void isTrue(boolean expression, String message)
Assert a boolean expression, throwing anIllegalArgumentException
if the expression evaluates tofalse
.Assert.isTrue(i > 0, "The value must be greater than zero");
- 参数:
expression
- a boolean expressionmessage
- the exception message to use if the assertion fails- 抛出:
IllegalArgumentException
- ifexpression
isfalse
isTrue
public static void isTrue(boolean expression, Supplier<String> messageSupplier)
Assert a boolean expression, throwing anIllegalArgumentException
if the expression evaluates tofalse
.Assert.isTrue(i > 0, () -> "The value '" + i + "' must be greater than zero");
- 参数:
expression
- a boolean expressionmessageSupplier
- a supplier for the exception message to use if the assertion fails- 抛出:
IllegalArgumentException
- ifexpression
isfalse
- 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 ofisTrue(boolean, String)
Assert a boolean expression, throwing anIllegalArgumentException
if the expression evaluates tofalse
.
isNull
public static void isNull(@Nullable Object object, String message)
Assert that an object isnull
.Assert.isNull(value, "The value must be null");
- 参数:
object
- the object to checkmessage
- the exception message to use if the assertion fails- 抛出:
IllegalArgumentException
- if the object is notnull
isNull
public static void isNull(@Nullable Object object, Supplier<String> messageSupplier)
Assert that an object isnull
.Assert.isNull(value, () -> "The value '" + value + "' must be null");
- 参数:
object
- the object to checkmessageSupplier
- a supplier for the exception message to use if the assertion fails- 抛出:
IllegalArgumentException
- if the object is notnull
- 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 ofisNull(Object, String)
Assert that an object isnull
.
notNull
public static void notNull(@Nullable Object object, String message)
Assert that an object is notnull
.Assert.notNull(clazz, "The class must not be null");
- 参数:
object
- the object to checkmessage
- the exception message to use if the assertion fails- 抛出:
IllegalArgumentException
- if the object isnull
notNull
public static void notNull(@Nullable Object object, Supplier<String> messageSupplier)
Assert that an object is notnull
.Assert.notNull(entity.getId(), () -> "ID for entity " + entity.getName() + " must not be null");
- 参数:
object
- the object to checkmessageSupplier
- a supplier for the exception message to use if the assertion fails- 抛出:
IllegalArgumentException
- if the object isnull
- 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 ofnotNull(Object, String)
Assert that an object is notnull
.
hasLength
public static void hasLength(@Nullable String text, String message)
Assert that the given String is not empty; that is, it must not benull
and not the empty String.Assert.hasLength(name, "Name must not be empty");
- 参数:
text
- the String to checkmessage
- 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 benull
and not the empty String.Assert.hasLength(account.getName(), () -> "Name for account '" + account.getId() + "' must not be empty");
- 参数:
text
- the String to checkmessageSupplier
- 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 ofhasLength(String, String)
Assert that the given String is not empty; that is, it must not benull
and not the empty 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 benull
and must contain at least one non-whitespace character.Assert.hasText(name, "'name' must not be empty");
- 参数:
text
- the String to checkmessage
- 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 benull
and must contain at least one non-whitespace character.Assert.hasText(account.getName(), () -> "Name for account '" + account.getId() + "' must not be empty");
- 参数:
text
- the String to checkmessageSupplier
- 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 ofhasText(String, String)
Assert that the given String contains valid text content; that is, it must not benull
and must contain at least one non-whitespace character.
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 searchsubstring
- the substring to find within the textmessage
- 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 searchsubstring
- the substring to find within the textmessageSupplier
- 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 ofdoesNotContain(String, String, String)
Assert that the given text does not contain the given substring.
notEmpty
public static void notEmpty(@Nullable Object[] array, String message)
Assert that an array contains elements; that is, it must not benull
and must contain at least one element.Assert.notEmpty(array, "The array must contain elements");
- 参数:
array
- the array to checkmessage
- the exception message to use if the assertion fails- 抛出:
IllegalArgumentException
- if the object array isnull
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 benull
and must contain at least one element.Assert.notEmpty(array, () -> "The " + arrayType + " array must contain elements");
- 参数:
array
- the array to checkmessageSupplier
- a supplier for the exception message to use if the assertion fails- 抛出:
IllegalArgumentException
- if the object array isnull
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 ofnotEmpty(Object[], String)
Assert that an array contains elements; that is, it must not benull
and must contain at least one element.
noNullElements
public static void noNullElements(@Nullable Object[] array, String message)
Assert that an array contains nonull
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 checkmessage
- the exception message to use if the assertion fails- 抛出:
IllegalArgumentException
- if the object array contains anull
element
noNullElements
public static void noNullElements(@Nullable Object[] array, Supplier<String> messageSupplier)
Assert that an array contains nonull
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 checkmessageSupplier
- a supplier for the exception message to use if the assertion fails- 抛出:
IllegalArgumentException
- if the object array contains anull
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 ofnoNullElements(Object[], String)
Assert that an array contains nonull
elements.
notEmpty
public static void notEmpty(@Nullable Collection<?> collection, String message)
Assert that a collection contains elements; that is, it must not benull
and must contain at least one element.Assert.notEmpty(collection, "Collection must contain elements");
- 参数:
collection
- the collection to checkmessage
- the exception message to use if the assertion fails- 抛出:
IllegalArgumentException
- if the collection isnull
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 benull
and must contain at least one element.Assert.notEmpty(collection, () -> "The " + collectionType + " collection must contain elements");
- 参数:
collection
- the collection to checkmessageSupplier
- a supplier for the exception message to use if the assertion fails- 抛出:
IllegalArgumentException
- if the collection isnull
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 ofnotEmpty(Collection, String)
Assert that a collection contains elements; that is, it must not benull
and must contain at least one element.
noNullElements
public static void noNullElements(@Nullable Collection<?> collection, String message)
Assert that a collection contains nonull
elements.Note: Does not complain if the collection is empty!
Assert.noNullElements(collection, "Collection must contain non-null elements");
- 参数:
collection
- the collection to checkmessage
- the exception message to use if the assertion fails- 抛出:
IllegalArgumentException
- if the collection contains anull
element- 从以下版本开始:
- 5.2
noNullElements
public static void noNullElements(@Nullable Collection<?> collection, Supplier<String> messageSupplier)
Assert that a collection contains nonull
elements.Note: Does not complain if the collection is empty!
Assert.noNullElements(collection, () -> "Collection " + collectionName + " must contain non-null elements");
- 参数:
collection
- the collection to checkmessageSupplier
- a supplier for the exception message to use if the assertion fails- 抛出:
IllegalArgumentException
- if the collection contains anull
element- 从以下版本开始:
- 5.2
notEmpty
public static void notEmpty(@Nullable Map<?,?> map, String message)
Assert that a Map contains entries; that is, it must not benull
and must contain at least one entry.Assert.notEmpty(map, "Map must contain entries");
- 参数:
map
- the map to checkmessage
- the exception message to use if the assertion fails- 抛出:
IllegalArgumentException
- if the map isnull
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 benull
and must contain at least one entry.Assert.notEmpty(map, () -> "The " + mapType + " map must contain entries");
- 参数:
map
- the map to checkmessageSupplier
- a supplier for the exception message to use if the assertion fails- 抛出:
IllegalArgumentException
- if the map isnull
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 ofnotEmpty(Map, String)
Assert that a Map contains entries; that is, it must not benull
and must contain at least one entry.
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 againstobj
- the object to checkmessage
- 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 againstobj
- the object to checkmessageSupplier
- a supplier for the exception message to use if the assertion fails. SeeisInstanceOf(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 againstobj
- 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 thatsuperType.isAssignableFrom(subType)
istrue
.Assert.isAssignable(Number.class, myClass, "Number expected");
- 参数:
superType
- the super type to check againstsubType
- the sub type to checkmessage
- 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 thatsuperType.isAssignableFrom(subType)
istrue
.Assert.isAssignable(Number.class, myClass, () -> "Processing " + myAttributeName + ":");
- 参数:
superType
- the super type to check againstsubType
- the sub type to checkmessageSupplier
- a supplier for the exception message to use if the assertion fails. SeeisAssignable(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 thatsuperType.isAssignableFrom(subType)
istrue
.Assert.isAssignable(Number.class, myClass);
- 参数:
superType
- the super type to checksubType
- the sub type to check- 抛出:
IllegalArgumentException
- if the classes are not assignable