Package io.vertigo.core.lang

Class Assertion

java.lang.Object

io.vertigo.core.lang.Assertion

public final class Assertion
extends Object

Assertions help us to build better code, with more robustness. Assertions have been introduced by B.Meyer in a language called Eiffel. An assertion allows you to design by contract. Each time an assertion fails, an specific exception is thrown. The following assertions help you to test if - an object is noT null => isNotNull - a string is not blank (and not null) =>isNotBlank - an expression is true or false =>isTrue or isFalse You can have a condition before running an assertion => when That's usefull when you want to test a pattern of an object that can be null. This assertion should be written in a fluent style to group all the assertions into a single block of code. Assertion can define a message and args. "hello {0}, an error occured on '{1}'", "foo", "bar" returns hello foo, an error occured on 'bar' You can use the simple quote ' inside the message.

Author:

pchretien, fconstantin

Method Summary

Modifier and Type	Method	Description
static Assertion	check()
Assertion	isFalse(boolean test, String msg, Object... params)	Checks if a boolean expression is False Throws an IllegalStateException with a pretty message if not.
Assertion	isNotBlank(String str)	Checks if a string is not blank (and not empty).
Assertion	isNotBlank(String str, String msg, Object... params)	Checks if a string is not blank (and not empty).
Assertion	isNotNull(Object o)	Checks if an object is not null.
Assertion	isNotNull(Object o, String msg, Object... params)	Checks if an object is not null.
Assertion	isNull(Object o)	Checks if an object is null.
Assertion	isNull(Object o, String msg, Object... params)	Checks if an object is null.
Assertion	isTrue(boolean test, String msg, Object... params)	Checks if a boolean expression is True Throws an IllegalStateException with a pretty message if not.
Assertion	isValid(Supplier<Assertion> assertionSupplier)	Checks if an assertion supplied is valid.
Assertion	when(boolean condition, Supplier<Assertion> assertionSupplier)	Evaluates an assertion when a condition is fulfilled.

Methods inherited from class java.lang.Object

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

Method Detail

check

public static Assertion check()

when

public Assertion when(boolean condition,
                      Supplier<Assertion> assertionSupplier)

Evaluates an assertion when a condition is fulfilled.

Parameters:

condition - the condition to check the assertion

assertionSupplier - the assertion to check when the condition is fulfilled

Returns:

the current assertion

isNotNull

public Assertion isNotNull(Object o)

Checks if an object is not null. Throws the famous NullPointerException if not.

Parameters:

o - the object

Returns:

the current assertion

isNotNull

public Assertion isNotNull(Object o,
                           String msg,
                           Object... params)

Checks if an object is not null. Throws the famous NullPointerException with a pretty message if not.

Parameters:

o - the object

msg - the message

params - the params of the message

Returns:

the current assertion

isNull

public Assertion isNull(Object o)

Checks if an object is null. Throws an IllegalStateException if not

Parameters:

o - the object

Returns:

the current assertion

isNull

public Assertion isNull(Object o,
                        String msg,
                        Object... params)

Checks if an object is null. Throws an illegalStateException with a pretty message if not.

Parameters:

o - the object

msg - the message

params - the params of the message

Returns:

the current assertion

isTrue

public Assertion isTrue(boolean test,
                        String msg,
                        Object... params)

Checks if a boolean expression is True Throws an IllegalStateException with a pretty message if not.

Parameters:

test - the boolean expression

msg - the message

params - the params of the message

Returns:

the current assertion

isFalse

public Assertion isFalse(boolean test,
                         String msg,
                         Object... params)

Checks if a boolean expression is False Throws an IllegalStateException with a pretty message if not.

Parameters:

test - the boolean expression

msg - the message

params - the params of the message

Returns:

the current assertion

isNotBlank

public Assertion isNotBlank(String str)

Checks if a string is not blank (and not empty). Throws an IllegalArgumentException if not.

Parameters:

str - the string

Returns:

the current assertion

isNotBlank

public Assertion isNotBlank(String str,
                            String msg,
                            Object... params)

Checks if a string is not blank (and not empty). Throws an IllegalArgumentException with a pretty message if not.

Parameters:

str - the string

msg - the message

params - the params of the message

Returns:

the current assertion

isValid

public Assertion isValid(Supplier<Assertion> assertionSupplier)

Checks if an assertion supplied is valid. Throws the Exception thrown by the assertion if not.

Parameters:

assertionSupplier - the assertion supplied

Returns:

the current assertion