org.macroing.cel4j.java.binary.util

Class Utilities

java.lang.Object

org.macroing.cel4j.java.binary.util.Utilities

public final class Utilities
extends java.lang.Object

A utility class that consists exclusively of static methods that performs various operations.

Since:

1.0.0

Author:

Jörgen Lundgren

Method Summary

Modifier and Type	Method and Description
static java.lang.String	optional(java.util.List<?> objects) Returns a String representation of a List of Objects.
static java.lang.String	optional(java.util.List<?> objects, java.lang.String left, java.lang.String right, java.lang.String separator) Returns a String representation of a List of Objects.
static java.lang.String	repeat(java.lang.String string, int repetition) Returns a String that consists of string repeated repetition times.
static <T> T[]	requireDeepNonNull(T[] objects, java.lang.String name) Verifies that the array objects and all elements in objects are not null.
static <T> java.util.List<T>	requireNonNullList(java.util.List<T> list) Verifies that list and all of its elements are not null.
static <T> java.util.List<T>	requireNonNullList(T object, T[] objects) Verifies that the List created by the mandatory object and the optional non-null array objects contains no null elements.
static int[]	requireRange(int[] array, int minimum, int maximum) Returns array, but only if its elements are within the range of minimum (inclusive) and maximum (inclusive).
static int	requireRange(int value, int minimum, int maximum) Checks that the specified value is within a given closed range, such as [minimum, maximum].
static int	requireRange(int value, int minimum, int maximum, java.lang.String name) Checks that the specified value is within a given closed range, such as [minimum, maximum].
static <K,V extends java.lang.Comparable<? super V>> java.util.Map<K,V>	sortByValue(java.util.Map<K,V> map) Returns a new Map that is a value-sorted version of map.

Methods inherited from class java.lang.Object

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

Method Detail

sortByValue

public static <K,V extends java.lang.Comparable<? super V>> java.util.Map<K,V> sortByValue(java.util.Map<K,V> map)

Returns a new Map that is a value-sorted version of map.

If map is null, a NullPointerException will be thrown.

Type Parameters:

K - the generic key type of the Map

V - the generic value type of the Map

Parameters:

map - a Map

Returns:

a new Map that is a value-sorted version of map

Throws:

java.lang.NullPointerException - thrown if, and only if, map is null

requireNonNullList

public static <T> java.util.List<T> requireNonNullList(java.util.List<T> list)

Verifies that list and all of its elements are not null.

Returns the List itself.

If list or any of its elements are null, a NullPointerException will be thrown.

Type Parameters:

T - the generic type of the List

Parameters:

list - the List to check for null references

Returns:

the List itself

Throws:

java.lang.NullPointerException - thrown if, and only if, list or any of its elements are null

requireNonNullList

public static <T> java.util.List<T> requireNonNullList(T object,
                                                       T[] objects)

Verifies that the List created by the mandatory object and the optional non-null array objects contains no null elements.

Returns a new List.

If object, objects or any of its elements are null, a NullPointerException will be thrown.

Type Parameters:

T - the generic type of the List

Parameters:

object - the mandatory Object to add

objects - the optional non-null array to add after object

Returns:

a new List

Throws:

java.lang.NullPointerException - thrown if, and only if, object, objects or any of its elements are null

optional

public static java.lang.String optional(java.util.List<?> objects)

Returns a String representation of a List of Objects.

If either objects or an element in objects are null, a NullPointerException will be thrown.

Calling this method is equivalent to the following:

 
 Utilities.optional(objects, "", "", ", ");
 
 

Parameters:

objects - a List with Objects

Returns:

a String representation of a List of Objects

Throws:

java.lang.NullPointerException - thrown if, and only if, either objects or an element in objects are null

optional

public static java.lang.String optional(java.util.List<?> objects,
                                        java.lang.String left,
                                        java.lang.String right,
                                        java.lang.String separator)

Returns a String representation of a List of Objects.

If either objects, an element in objects, left, right or separator are null, a NullPointerException will be thrown.

The method is called optional because, if objects is empty, an empty String will be returned. Otherwise, left will be appended first, followed by the String representation of each Object in objects, all separated with separator and finally, right will be appended last.

Parameters:

objects - a List with Objects

left - the String that will be appended first, if objects is not empty

right - the String that will be appended last, if objects is not empty

separator - the String that will be used as separator or delimiter between the String representation of each Object in objects

Returns:

a String representation of a List of Objects

Throws:

java.lang.NullPointerException - thrown if, and only if, either objects, an element in objects, left, right or separator are null

requireDeepNonNull

public static <T> T[] requireDeepNonNull(T[] objects,
                                         java.lang.String name)

Verifies that the array objects and all elements in objects are not null.

Returns objects.

If either objects, an element in objects or name are null, a NullPointerException will be thrown.

Type Parameters:

T - the generic type of the array

Parameters:

objects - the array to verify

name - the name of the variable that will be part of the message in the NullPointerException

Returns:

objects

Throws:

java.lang.NullPointerException - thrown if, and only if, either objects, an element in objects or name are null

requireRange

public static int requireRange(int value,
                               int minimum,
                               int maximum)

Checks that the specified value is within a given closed range, such as [minimum, maximum].

Returns the value itself.

If value is less than minimum or greater than maximum, an IllegalArgumentException will be thrown.

This method is implemented in terms of requireRange(int, int, int, String), with a name of "value".

Parameters:

value - the value to check

minimum - the minimum (inclusive) bound of the range

maximum - the maximum (inclusive) bound of the range

Returns:

the value itself

Throws:

java.lang.IllegalArgumentException - thrown if, and only if, value is less than minimum or greater than maximum

requireRange

public static int requireRange(int value,
                               int minimum,
                               int maximum,
                               java.lang.String name)

Checks that the specified value is within a given closed range, such as [minimum, maximum].

Returns the value itself.

If value is less than minimum or greater than maximum, an IllegalArgumentException will be thrown.

If name is null, a NullPointerException will be thrown.

Parameters:

value - the value to check

minimum - the minimum (inclusive) bound of the range

maximum - the maximum (inclusive) bound of the range

name - the name of the value, that will be part of the message to the IllegalArgumentException, if thrown

Returns:

the value itself

Throws:

java.lang.IllegalArgumentException - thrown if, and only if, value is less than minimum or greater than maximum

java.lang.NullPointerException - thrown if, and only if, name is null

requireRange

public static int[] requireRange(int[] array,
                                 int minimum,
                                 int maximum)

Returns array, but only if its elements are within the range of minimum (inclusive) and maximum (inclusive).

If one or more of its elements are not within said range, an IllegalArgumentException will be thrown.

If array is null, a NullPointerException will be thrown.

Parameters:

array - the array with elements to verify

minimum - the minimum value allowed (inclusive)

maximum - the maximum value allowed (inclusive)

Returns:

array, but only if its elements are within the range of minimum (inclusive) and maximum (inclusive)

Throws:

java.lang.IllegalArgumentException - thrown if, and only if, array contains an element that is less than minimum or greater than maximum

java.lang.NullPointerException - thrown if, and only if, array is null

repeat

public static java.lang.String repeat(java.lang.String string,
                                      int repetition)

Returns a String that consists of string repeated repetition times.

If string is null, the String literal "null" will be repeated repetition times.

If repetition is less than or equal to 0, an empty String will be returned.

Parameters:

string - the String to repeat

repetition - how many times string should be repeated

Returns:

a String that consists of string repeated repetition times