io.greptime.common.util

Class Ensures

java.lang.Object

io.greptime.common.util.Ensures

public final class Ensures
extends Object

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

Author:

jiachun.fjc

Method Summary

Modifier and Type	Method and Description
static void	ensure(boolean expression) Ensures the truth of an expression involving one or more parameters to the calling method.
static void	ensure(boolean expression, Object message) Ensures the truth of an expression involving one or more parameters to the calling method.
static void	ensure(boolean expression, String fmt, Object... args) Ensures the truth of an expression involving one or more parameters to the calling method.
static <T> T	ensureNonNull(T obj) Checks that the specified object reference is not null.
static <T> T	ensureNonNull(T obj, String message) Checks that the specified object reference is not null and throws a customized NullPointerException if it is.
static <T> T	ensureNonNull(T obj, String fmt, Object... args) Checks that the specified object reference is not null and throws a customized NullPointerException if it is.

Methods inherited from class java.lang.Object

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

Method Detail

ensureNonNull

public static <T> T ensureNonNull(T obj)

Checks that the specified object reference is not null.

Type Parameters:

T - the type of the reference

Parameters:

obj - the object reference to check for nullity

Returns:

obj if not null

Throws:

NullPointerException - if obj is null

ensureNonNull

public static <T> T ensureNonNull(T obj,
                                  String message)

Checks that the specified object reference is not null and throws a customized NullPointerException if it is.

Type Parameters:

T - the type of the reference

Parameters:

obj - the object reference to check for nullity

message - detail message to be used in the event that a NullPointerException is thrown

Returns:

obj if not null

Throws:

NullPointerException - if obj is null

ensureNonNull

public static <T> T ensureNonNull(T obj,
                                  String fmt,
                                  Object... args)

Checks that the specified object reference is not null and throws a customized NullPointerException if it is.

Type Parameters:

T - the type of the reference

Parameters:

obj - the object reference to check for nullity

fmt - the exception message with format string

args - arguments referenced by the format specifiers in the format string

Returns:

obj if not null

Throws:

NullPointerException - if obj is null

ensure

public static void ensure(boolean expression)

Ensures the truth of an expression involving one or more parameters to the calling method.

Parameters:

expression - a boolean expression

Throws:

IllegalArgumentException - if expression is false

ensure

public static void ensure(boolean expression,
                          Object message)

Ensures the truth of an expression involving one or more parameters to the calling method.

Parameters:

expression - a boolean expression

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

Throws:

IllegalArgumentException - if expression is false

ensure

public static void ensure(boolean expression,
                          String fmt,
                          Object... args)

Ensures the truth of an expression involving one or more parameters to the calling method.

Parameters:

expression - a boolean expression

fmt - the exception message with format string

args - arguments referenced by the format specifiers in the format string

Throws:

IllegalArgumentException - if expression is false