Package io.activej.common

Class Checks

java.lang.Object

io.activej.common.Checks

public final class Checks
extends Object

This class is used for determining whether Checks should be enabled or not. It is sometimes useful to disable preconditions checks at runtime environment to squeeze out more performance in a tight loop.

The common pattern is having a

 private static final boolean CHECK = Check.isEnabled(MyClass.class);
 

constant in your class. When using Checks just wrap the call in if-statement like so:

 if (CHECK) Preconditions.checkNotNull(value);
 

By default, all checks are disabled (like java asserts). To enable all checks you can run application with system property -Dchk=on You can enable or disable checks for the whole package (with its subpackages) or for individual classes like so: -Dchk:io.activej.eventloop=on -Dchk:io.activej.promise.Promise=off.

Constructor Summary

Constructors

Constructor	Description
Checks()

Method Summary

Modifier and Type	Method	Description
static void	checkArgument(boolean expression)	Checks a validity of an argument
static void	checkArgument(boolean expression, Object message)	Checks a validity of an argument
static void	checkArgument(boolean expression, String template, Object... args)	Checks a validity of an argument
static void	checkArgument(boolean expression, Supplier<String> message)	Checks a validity of an argument
static <T> T	checkArgument(T argument, Predicate<T> predicate)	Checks a validity of a given argument
static <T> T	checkArgument(T argument, Predicate<T> predicate, Object message)	Checks a validity of a given argument
static <T> T	checkArgument(T argument, Predicate<T> predicate, String template, Object... args)	Checks a validity of a given argument
static <T> T	checkArgument(T argument, Predicate<T> predicate, Function<T,String> message)	Checks a validity of a given argument
static <T> T	checkArgument(T argument, Predicate<T> predicate, Supplier<String> message)	Checks a validity of a given argument
static <T> T	checkNotNull(T reference)	Checks an object for nullness
static <T> T	checkNotNull(T reference, Object message)	Checks an object for nullness
static <T> T	checkNotNull(T reference, String template, Object... args)	Checks an object for nullness
static <T> T	checkNotNull(T reference, Supplier<String> message)	Checks an object for nullness
static void	checkState(boolean expression)	Checks a validity of a state
static void	checkState(boolean expression, Object message)	Checks a validity of a state
static void	checkState(boolean expression, String template, Object... args)	Checks a validity of a state
static void	checkState(boolean expression, Supplier<String> message)	Checks a validity of a state
static boolean	isEnabled(Class<?> cls)	Indicates whether checks are enabled or disabled for the specified class
static boolean	isEnabledByDefault()	Returns a boolean that indicates whether checks are enabled by default

Methods inherited from class java.lang.Object

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

Constructor Details

Checks

public Checks()

Method Details

isEnabled

public static boolean isEnabled(Class<?> cls)

Indicates whether checks are enabled or disabled for the specified class

Parameters:

cls - class to be checked

Returns:

true if checks are enabled for the given class, false otherwise

isEnabledByDefault

public static boolean isEnabledByDefault()

Returns a boolean that indicates whether checks are enabled by default

checkNotNull

@NotNull
public static <T> T checkNotNull(@Nullable
 T reference)

Checks an object for nullness

If an object is not null then it is returned as-is. Otherwise, a NullPointerException is thrown

Type Parameters:

T - a type of object to be checked

Parameters:

reference - an object to be checked for nullness

Returns:

a checked object

Throws:

NullPointerException - if an object is null

checkNotNull

@NotNull
public static <T> T checkNotNull(@Nullable
 T reference,
 Object message)

Checks an object for nullness

If an object is not null then it is returned as-is. Otherwise, a NullPointerException is thrown with a specified message

Type Parameters:

T - a type of object to be checked

Parameters:

reference - an object to be checked for nullness

message - an object that represents a message to be used in thrown NullPointerException

Returns:

a checked object

Throws:

NullPointerException - if an object is null

checkNotNull

@NotNull
public static <T> T checkNotNull(@Nullable
 T reference,
 Supplier<String> message)

Checks an object for nullness

If an object is not null then it is returned as-is. Otherwise, a NullPointerException is thrown with a supplied message

Type Parameters:

T - a type of object to be checked

Parameters:

reference - an object to be checked for nullness

message - a supplier of message to be used in thrown NullPointerException

Returns:

a checked object

Throws:

NullPointerException - if an object is null

checkNotNull

@NotNull
public static <T> T checkNotNull(@Nullable
 T reference,
 String template,
 Object... args)

Checks an object for nullness

If an object is not null then it is returned as-is. Otherwise, a NullPointerException is thrown with a templated message

Type Parameters:

T - a type of object to be checked

Parameters:

reference - an object to be checked for nullness

template - a template of message to be used in thrown NullPointerException

args - arguments to an error message template

Returns:

a checked object

Throws:

NullPointerException - if an object is null

See Also:

• String.format(String, Object...)

checkState

public static void checkState(boolean expression)

Checks a validity of a state

If a given expression is true then a method finishes successfully. Otherwise, an IllegalStateException is thrown

Parameters:

expression - a boolean that represents a validity of a state

Throws:

IllegalStateException - if a state is not valid

checkState

public static void checkState(boolean expression,
 Object message)

Checks a validity of a state

If a given expression is true then a method finishes successfully. Otherwise, an IllegalStateException is thrown with a specified message

Parameters:

expression - a boolean that represents a validity of a state

message - an object that represents a message to be used in thrown IllegalStateException

Throws:

IllegalStateException - if a state is not valid

checkState

public static void checkState(boolean expression,
 Supplier<String> message)

Checks a validity of a state

If a given expression is true then a method finishes successfully. Otherwise, an IllegalStateException is thrown with a supplied message

Parameters:

expression - a boolean that represents a validity of a state

message - a supplier of message to be used in thrown IllegalStateException

Throws:

IllegalStateException - if a state is not valid

checkState

public static void checkState(boolean expression,
 String template,
 Object... args)

Checks a validity of a state

If a given expression is true then a method finishes successfully. Otherwise, an IllegalStateException is thrown with a supplied message

Parameters:

expression - a boolean that represents a validity of a state

template - a template of message to be used in thrown IllegalStateException

args - arguments to an error message template

Throws:

IllegalStateException - if a state is not valid

See Also:

• String.format(String, Object...)

checkArgument

public static void checkArgument(boolean expression)

Checks a validity of an argument

If a given expression is true then a method finishes successfully. Otherwise, an IllegalArgumentException is thrown

Parameters:

expression - a boolean that represents a validity of an argument

Throws:

IllegalArgumentException - if an argument is not valid

checkArgument

public static void checkArgument(boolean expression,
 Object message)

Checks a validity of an argument

If a given expression is true then a method finishes successfully. Otherwise, an IllegalArgumentException is thrown with a specified message

Parameters:

expression - a boolean that represents a validity of an argument

message - an object that represents a message to be used in thrown IllegalArgumentException

Throws:

IllegalArgumentException - if an argument is not valid

checkArgument

public static void checkArgument(boolean expression,
 Supplier<String> message)

Checks a validity of an argument

If a given expression is true then a method finishes successfully. Otherwise, an IllegalArgumentException is thrown with a supplied message

Parameters:

expression - a boolean that represents a validity of an argument

message - a supplier of message to be used in thrown IllegalArgumentException

Throws:

IllegalArgumentException - if an argument is not valid

checkArgument

public static void checkArgument(boolean expression,
 String template,
 Object... args)

Checks a validity of an argument

If a given expression is true then a method finishes successfully. Otherwise, an IllegalArgumentException is thrown with a supplied message

Parameters:

expression - a boolean that represents a validity of an argument

template - a template of message to be used in thrown IllegalArgumentException

args - arguments to an error message template

Throws:

IllegalArgumentException - if an argument is not valid

See Also:

• String.format(String, Object...)

checkArgument

public static <T> T checkArgument(T argument,
 Predicate<T> predicate)

Checks a validity of a given argument

If an argument is valid then an argument is returned as-is. Otherwise, an IllegalArgumentException is thrown

Parameters:

argument - an argument to be checked for validity

predicate - a predicate that checks an argument for validity

Throws:

IllegalArgumentException - if an argument is not valid

checkArgument

public static <T> T checkArgument(T argument,
 Predicate<T> predicate,
 Object message)

Checks a validity of a given argument

If an argument is valid then an argument is returned as-is. Otherwise, an IllegalArgumentException is thrown with a specified message

Parameters:

argument - an argument to be checked for validity

predicate - a predicate that checks an argument for validity

message - an object that represents a message to be used in thrown IllegalArgumentException

Throws:

IllegalArgumentException - if an argument is not valid

checkArgument

public static <T> T checkArgument(T argument,
 Predicate<T> predicate,
 Supplier<String> message)

Checks a validity of a given argument

If an argument is valid then an argument is returned as-is. Otherwise, an IllegalArgumentException is thrown with a supplied message

Parameters:

argument - an argument to be checked for validity

predicate - a predicate that checks an argument for validity

message - a supplier of message to be used in thrown IllegalArgumentException

Throws:

IllegalArgumentException - if an argument is not valid

checkArgument

public static <T> T checkArgument(T argument,
 Predicate<T> predicate,
 Function<T,String> message)

Checks a validity of a given argument

If an argument is valid then an argument is returned as-is. Otherwise, an IllegalArgumentException is thrown with a supplied message

Parameters:

argument - an argument to be checked for validity

predicate - a predicate that checks an argument for validity

message - a function that transforms an argument into an error message to be used in thrown IllegalArgumentException

Throws:

IllegalArgumentException - if an argument is not valid

checkArgument

public static <T> T checkArgument(T argument,
 Predicate<T> predicate,
 String template,
 Object... args)

Checks a validity of a given argument

If an argument is valid then an argument is returned as-is. Otherwise, an IllegalArgumentException is thrown with a supplied message

Parameters:

argument - an argument to be checked for validity

predicate - a predicate that checks an argument for validity

template - a template of message to be used in thrown IllegalArgumentException

args - arguments to an error message template

Throws:

IllegalArgumentException - if an argument is not valid