io.julian.common

类 Preconditions

java.lang.Object

io.julian.common.Preconditions

public class Preconditions
extends java.lang.Object

Simple static methods to be called at the start of your own methods to verify correct arguments and state.

构造器概要

构造器

构造器和说明
Preconditions()

方法概要

限定符和类型	方法和说明
static void	checkArgument(boolean expression)
static void	checkArgument(boolean expression, java.lang.Object errorMessage) Ensures that an expression checking an argument is true.
static float	checkArgumentFinite(float value, java.lang.String valueName) Ensures that the argument floating point value is a finite number.
static float	checkArgumentInRange(float value, float lower, float upper, java.lang.String valueName) Ensures that the argument floating point value is within the inclusive range.
static int	checkArgumentInRange(int value, int lower, int upper, java.lang.String valueName) Ensures that the argument int value is within the inclusive range.
static long	checkArgumentInRange(long value, long lower, long upper, java.lang.String valueName) Ensures that the argument long value is within the inclusive range.
static int	checkArgumentNonnegative(int value) Ensures that that the argument numeric value is non-negative.
static int	checkArgumentNonnegative(int value, java.lang.String errorMessage) Ensures that that the argument numeric value is non-negative.
static long	checkArgumentNonnegative(long value) Ensures that that the argument numeric value is non-negative.
static long	checkArgumentNonnegative(long value, java.lang.String errorMessage) Ensures that that the argument numeric value is non-negative.
static int	checkArgumentPositive(int value, java.lang.String errorMessage) Ensures that that the argument numeric value is positive.
static float[]	checkArrayElementsInRange(float[] value, float lower, float upper, java.lang.String valueName) Ensures that all elements in the argument floating point array are within the inclusive range While this can be used to range check against +/- infinity, note that all NaN numbers will always be out of range.
static <T> T[]	checkArrayElementsNotNull(T[] value, java.lang.String valueName) Ensures that the array is not null, and none of its elements are null.
static <C extends java.util.Collection<T>,T> C	checkCollectionElementsNotNull(C value, java.lang.String valueName) Ensures that the Collection is not null, and none of its elements are null.
static <T> java.util.Collection<T>	checkCollectionNotEmpty(java.util.Collection<T> value, java.lang.String valueName) Ensures that the Collection is not null, and contains at least one element.
static int	checkFlagsArgument(int requestedFlags, int allowedFlags) Check the requested flags, throwing if any requested flags are outside the allowed set.
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 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.String message) Ensures the truth of an expression involving the state of the calling instance, but not involving any parameters to the calling method.
static <T extends java.lang.CharSequence> T	checkStringNotEmpty(T string) Ensures that an string reference passed as a parameter to the calling method is not empty.
static <T extends java.lang.CharSequence> T	checkStringNotEmpty(T string, java.lang.Object errorMessage) Ensures that an string reference passed as a parameter to the calling method is not empty.

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

Preconditions

public Preconditions()

方法详细资料

checkArgument

public static void checkArgument(boolean expression)

checkArgument

public static void checkArgument(boolean expression,
                                 java.lang.Object errorMessage)

Ensures that an expression checking an argument is true.

参数:

expression - the expression to check

errorMessage - the exception message to use if the check fails; will be converted to a string using String.valueOf(Object)

抛出:

java.lang.IllegalArgumentException - if expression is false

checkStringNotEmpty

@NonNull
public static <T extends java.lang.CharSequence> T checkStringNotEmpty(T string)

Ensures that an string reference passed as a parameter to the calling method is not empty.

参数:

string - an string reference

返回:

the string reference that was validated

抛出:

java.lang.IllegalArgumentException - if string is empty

checkStringNotEmpty

@NonNull
public static <T extends java.lang.CharSequence> T checkStringNotEmpty(T string,
                                                                                java.lang.Object errorMessage)

Ensures that an string reference passed as a parameter to the calling method is not empty.

参数:

string - an string reference

errorMessage - the exception message to use if the check fails; will be converted to a string using String.valueOf(Object)

返回:

the string reference that was validated

抛出:

java.lang.IllegalArgumentException - if string is empty

checkNotNull

@NonNull
public static <T> T checkNotNull(T reference)

Ensures that an object reference passed as a parameter to the calling method is not null.

参数:

reference - an object reference

返回:

the non-null reference that was validated

抛出:

java.lang.NullPointerException - if reference is null

checkNotNull

@NonNull
public 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.

参数:

reference - an object reference

errorMessage - the exception message to use if the check fails; will be converted to a string using String.valueOf(Object)

返回:

the non-null reference that was validated

抛出:

java.lang.NullPointerException - if reference is null

checkState

public static void checkState(boolean expression,
                              java.lang.String message)

Ensures the truth of an expression involving the state of the calling instance, but not involving any parameters to the calling method.

参数:

expression - a boolean expression

message - exception message

抛出:

java.lang.IllegalStateException - if expression is false

checkState

public 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.

参数:

expression - a boolean expression

抛出:

java.lang.IllegalStateException - if expression is false

checkFlagsArgument

public static int checkFlagsArgument(int requestedFlags,
                                     int allowedFlags)

Check the requested flags, throwing if any requested flags are outside the allowed set.

返回:

the validated requested flags.

checkArgumentNonnegative

public static int checkArgumentNonnegative(int value,
                                           java.lang.String errorMessage)

Ensures that that the argument numeric value is non-negative.

参数:

value - a numeric int value

errorMessage - the exception message to use if the check fails

返回:

the validated numeric value

抛出:

java.lang.IllegalArgumentException - if value was negative

checkArgumentNonnegative

public static int checkArgumentNonnegative(int value)

Ensures that that the argument numeric value is non-negative.

参数:

value - a numeric int value

返回:

the validated numeric value

抛出:

java.lang.IllegalArgumentException - if value was negative

checkArgumentNonnegative

public static long checkArgumentNonnegative(long value)

Ensures that that the argument numeric value is non-negative.

参数:

value - a numeric long value

返回:

the validated numeric value

抛出:

java.lang.IllegalArgumentException - if value was negative

checkArgumentNonnegative

public static long checkArgumentNonnegative(long value,
                                            java.lang.String errorMessage)

Ensures that that the argument numeric value is non-negative.

参数:

value - a numeric long value

errorMessage - the exception message to use if the check fails

返回:

the validated numeric value

抛出:

java.lang.IllegalArgumentException - if value was negative

checkArgumentPositive

public static int checkArgumentPositive(int value,
                                        java.lang.String errorMessage)

Ensures that that the argument numeric value is positive.

参数:

value - a numeric int value

errorMessage - the exception message to use if the check fails

返回:

the validated numeric value

抛出:

java.lang.IllegalArgumentException - if value was not positive

checkArgumentFinite

public static float checkArgumentFinite(float value,
                                        java.lang.String valueName)

Ensures that the argument floating point value is a finite number.

A finite number is defined to be both representable (that is, not NaN) and not infinite (that is neither positive or negative infinity).

参数:

value - a floating point value

valueName - the name of the argument to use if the check fails

返回:

the validated floating point value

抛出:

java.lang.IllegalArgumentException - if value was not finite

checkArgumentInRange

public static float checkArgumentInRange(float value,
                                         float lower,
                                         float upper,
                                         java.lang.String valueName)

Ensures that the argument floating point value is within the inclusive range.

While this can be used to range check against +/- infinity, note that all NaN numbers will always be out of range.

参数:

value - a floating point value

lower - the lower endpoint of the inclusive range

upper - the upper endpoint of the inclusive range

valueName - the name of the argument to use if the check fails

返回:

the validated floating point value

抛出:

java.lang.IllegalArgumentException - if value was not within the range

checkArgumentInRange

public static int checkArgumentInRange(int value,
                                       int lower,
                                       int upper,
                                       java.lang.String valueName)

Ensures that the argument int value is within the inclusive range.

参数:

value - a int value

lower - the lower endpoint of the inclusive range

upper - the upper endpoint of the inclusive range

valueName - the name of the argument to use if the check fails

返回:

the validated int value

抛出:

java.lang.IllegalArgumentException - if value was not within the range

checkArgumentInRange

public static long checkArgumentInRange(long value,
                                        long lower,
                                        long upper,
                                        java.lang.String valueName)

Ensures that the argument long value is within the inclusive range.

参数:

value - a long value

lower - the lower endpoint of the inclusive range

upper - the upper endpoint of the inclusive range

valueName - the name of the argument to use if the check fails

返回:

the validated long value

抛出:

java.lang.IllegalArgumentException - if value was not within the range

checkArrayElementsNotNull

public static <T> T[] checkArrayElementsNotNull(T[] value,
                                                java.lang.String valueName)

Ensures that the array is not null, and none of its elements are null.

参数:

value - an array of boxed objects

valueName - the name of the argument to use if the check fails

返回:

the validated array

抛出:

java.lang.NullPointerException - if the value or any of its elements were null

checkCollectionElementsNotNull

@NonNull
public static <C extends java.util.Collection<T>,T> C checkCollectionElementsNotNull(C value,
                                                                                              java.lang.String valueName)

Ensures that the Collection is not null, and none of its elements are null.

参数:

value - a Collection of boxed objects

valueName - the name of the argument to use if the check fails

返回:

the validated Collection

抛出:

java.lang.NullPointerException - if the value or any of its elements were null

checkCollectionNotEmpty

public static <T> java.util.Collection<T> checkCollectionNotEmpty(java.util.Collection<T> value,
                                                                  java.lang.String valueName)

Ensures that the Collection is not null, and contains at least one element.

参数:

value - a Collection of boxed elements.

valueName - the name of the argument to use if the check fails.

返回:

the validated Collection

抛出:

java.lang.NullPointerException - if the value was null

java.lang.IllegalArgumentException - if the value was empty

checkArrayElementsInRange

public static float[] checkArrayElementsInRange(float[] value,
                                                float lower,
                                                float upper,
                                                java.lang.String valueName)

Ensures that all elements in the argument floating point array are within the inclusive range

While this can be used to range check against +/- infinity, note that all NaN numbers will always be out of range.

参数:

value - a floating point array of values

lower - the lower endpoint of the inclusive range

upper - the upper endpoint of the inclusive range

valueName - the name of the argument to use if the check fails

返回:

the validated floating point value

抛出:

java.lang.IllegalArgumentException - if any of the elements in value were out of range

java.lang.NullPointerException - if the value was null