public final class Preconditions
extends java.lang.Object
| 限定符和类型 | 方法和说明 |
|---|---|
static void |
checkArgument(boolean expression)
Ensures the truth of an expression involving one or more parameters to the calling method.
|
static void |
checkArgument(boolean expression,
java.lang.Object errorMessage)
Ensures the truth of an expression involving one or more parameters to the calling method.
|
static void |
checkArgument(boolean expression,
java.lang.String errorMessageTemplate,
java.lang.Object... errorMessageArgs)
Ensures the truth of an expression involving one or more parameters to the calling method.
|
static int |
checkElementIndex(int index,
int size)
Ensures that
index specifies a valid element in an array, list or string of size
size. |
static int |
checkElementIndex(int index,
int size,
java.lang.String desc)
Ensures that
index specifies a valid element in an array, list or string of size
size. |
static <T> T |
checkNotNull(T reference)
Ensures that an object reference passed as a parameter to the calling method is not null.
|
static <T> T |
checkNotNull(T reference,
java.lang.Object errorMessage)
Ensures that an object reference passed as a parameter to the calling method is not null.
|
static <T> T |
checkNotNull(T reference,
java.lang.String errorMessageTemplate,
java.lang.Object... errorMessageArgs)
Ensures that an object reference passed as a parameter to the calling method is not null.
|
static int |
checkPositionIndex(int index,
int size)
Ensures that
index specifies a valid position in an array, list or string of
size size. |
static int |
checkPositionIndex(int index,
int size,
java.lang.String desc)
Ensures that
index specifies a valid position in an array, list or string of
size size. |
static void |
checkPositionIndexes(int start,
int end,
int size)
Ensures that
start and end specify a valid positions in an array, list
or string of size size, and are in order. |
static void |
checkState(boolean expression)
Ensures the truth of an expression involving the state of the calling instance, but not
involving any parameters to the calling method.
|
static void |
checkState(boolean expression,
java.lang.Object errorMessage)
Ensures the truth of an expression involving the state of the calling instance, but not
involving any parameters to the calling method.
|
static void |
checkState(boolean expression,
java.lang.String errorMessageTemplate,
java.lang.Object... errorMessageArgs)
Ensures the truth of an expression involving the state of the calling instance, but not
involving any parameters to the calling method.
|
public static void checkArgument(boolean expression)
expression - a boolean expressionjava.lang.IllegalArgumentException - if expression is falsepublic static void checkArgument(boolean expression,
@Nullable
java.lang.Object errorMessage)
expression - a boolean expressionerrorMessage - the exception message to use if the check fails; will be converted to a
string using String.valueOf(Object)java.lang.IllegalArgumentException - if expression is falsepublic static void checkArgument(boolean expression,
@Nullable
java.lang.String errorMessageTemplate,
@Nullable
java.lang.Object... errorMessageArgs)
expression - a boolean expressionerrorMessageTemplate - a template for the exception message should the check fail. The
message is formed by replacing each %s placeholder in the template with an
argument. These are matched by position - the first %s gets errorMessageArgs[0], etc. Unmatched arguments will be appended to the formatted message
in square braces. Unmatched placeholders will be left as-is.errorMessageArgs - the arguments to be substituted into the message template. Arguments
are converted to strings using String.valueOf(Object).java.lang.IllegalArgumentException - if expression is falsejava.lang.NullPointerException - if the check fails and either errorMessageTemplate or
errorMessageArgs is null (don't let this happen)public static void checkState(boolean expression)
expression - a boolean expressionjava.lang.IllegalStateException - if expression is falsepublic static void checkState(boolean expression,
@Nullable
java.lang.Object errorMessage)
expression - a boolean expressionerrorMessage - the exception message to use if the check fails; will be converted to a
string using String.valueOf(Object)java.lang.IllegalStateException - if expression is falsepublic static void checkState(boolean expression,
@Nullable
java.lang.String errorMessageTemplate,
@Nullable
java.lang.Object... errorMessageArgs)
expression - a boolean expressionerrorMessageTemplate - a template for the exception message should the check fail. The
message is formed by replacing each %s placeholder in the template with an
argument. These are matched by position - the first %s gets errorMessageArgs[0], etc. Unmatched arguments will be appended to the formatted message
in square braces. Unmatched placeholders will be left as-is.errorMessageArgs - the arguments to be substituted into the message template. Arguments
are converted to strings using String.valueOf(Object).java.lang.IllegalStateException - if expression is falsejava.lang.NullPointerException - if the check fails and either errorMessageTemplate or
errorMessageArgs is null (don't let this happen)public static <T> T checkNotNull(T reference)
reference - an object referencejava.lang.NullPointerException - if reference is nullpublic static <T> T checkNotNull(T reference,
@Nullable
java.lang.Object errorMessage)
reference - an object referenceerrorMessage - the exception message to use if the check fails; will be converted to a
string using String.valueOf(Object)java.lang.NullPointerException - if reference is nullpublic static <T> T checkNotNull(T reference,
@Nullable
java.lang.String errorMessageTemplate,
@Nullable
java.lang.Object... errorMessageArgs)
reference - an object referenceerrorMessageTemplate - a template for the exception message should the check fail. The
message is formed by replacing each %s placeholder in the template with an
argument. These are matched by position - the first %s gets errorMessageArgs[0], etc. Unmatched arguments will be appended to the formatted message
in square braces. Unmatched placeholders will be left as-is.errorMessageArgs - the arguments to be substituted into the message template. Arguments
are converted to strings using String.valueOf(Object).java.lang.NullPointerException - if reference is nullpublic static int checkElementIndex(int index,
int size)
index specifies a valid element in an array, list or string of size
size. An element index may range from zero, inclusive, to size, exclusive.index - a user-supplied index identifying an element of an array, list or stringsize - the size of that array, list or stringindexjava.lang.IndexOutOfBoundsException - if index is negative or is not less than sizejava.lang.IllegalArgumentException - if size is negativepublic static int checkElementIndex(int index,
int size,
@Nullable
java.lang.String desc)
index specifies a valid element in an array, list or string of size
size. An element index may range from zero, inclusive, to size, exclusive.index - a user-supplied index identifying an element of an array, list or stringsize - the size of that array, list or stringdesc - the text to use to describe this index in an error messageindexjava.lang.IndexOutOfBoundsException - if index is negative or is not less than sizejava.lang.IllegalArgumentException - if size is negativepublic static int checkPositionIndex(int index,
int size)
index specifies a valid position in an array, list or string of
size size. A position index may range from zero to size, inclusive.index - a user-supplied index identifying a position in an array, list or stringsize - the size of that array, list or stringindexjava.lang.IndexOutOfBoundsException - if index is negative or is greater than sizejava.lang.IllegalArgumentException - if size is negativepublic static int checkPositionIndex(int index,
int size,
@Nullable
java.lang.String desc)
index specifies a valid position in an array, list or string of
size size. A position index may range from zero to size, inclusive.index - a user-supplied index identifying a position in an array, list or stringsize - the size of that array, list or stringdesc - the text to use to describe this index in an error messageindexjava.lang.IndexOutOfBoundsException - if index is negative or is greater than sizejava.lang.IllegalArgumentException - if size is negativepublic static void checkPositionIndexes(int start,
int end,
int size)
start and end specify a valid positions in an array, list
or string of size size, and are in order. A position index may range from zero to
size, inclusive.start - a user-supplied index identifying a starting position in an array, list or stringend - a user-supplied index identifying a ending position in an array, list or stringsize - the size of that array, list or stringjava.lang.IndexOutOfBoundsException - if either index is negative or is greater than size,
or if end is less than startjava.lang.IllegalArgumentException - if size is negative