Class Utils

java.lang.Object

io.github.valentinherrmann.levenshtein.Utils

public final class Utils
extends Object

Method Summary

Modifier and Type	Method	Description
static boolean	canContain(Class<?> actualType, Class<?> expectedType)	Checks if the actual primitive type can contain the expected primitive type, i.e. whether Java's widening primitive conversion goes from the expected to the actual type.
static boolean	isNameWithinDeviation(String expectedName, String actualName, int threshold)	Checks if names are within a specified deviation threshold.
static boolean	isNumericDeviation(Class<?> expected, Class<?> actual)	Checks whether two types are different numeric types in either direction (e.g.
static int	levenshteinDistance(String s1, String s2)	Calculates the Levenshtein distance between two strings.
static double	levenshteinDistancePercent(String expected, String actual)	Calculates the Levenshtein distance as percentage of the length of the longer string.
static Object	safeCast(Object val, Class<?> castTo)	Converts a value to the given type: returns the value itself if it already is an instance, or converts between numeric types (e.g. an int result where a double is expected; char counts as numeric type).
static Object	safeCast(Object val, Class<?> castTo, boolean allowNull)	Like safeCast(Object, Class), but optionally permits null.
static WrapperProperty.Existence	selectWorstExistence(WrapperProperty.Existence worst, WrapperProperty.Existence updated)	Selects the worse existence state between two states, ignoring UNCHECKED.
static Class<?>	toWrapperType(Class<?> type)	Converts a primitive type to its corresponding wrapper type.
static Class<?>	unwrapPrimitive(Class<?> type)	Unwraps a primitive wrapper class to its corresponding primitive type.
static void	verifyType(WrapperProperty<Class<?>> typeWrapperProperty, Class<?> actualType)	Verifies that the actual type matches or is compatible with the expected type.

Methods inherited from class Object

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

Method Details

levenshteinDistance

public static int levenshteinDistance(String s1,
 String s2)

Calculates the Levenshtein distance between two strings.

Parameters:

s1 - First string

s2 - Second string

Returns:

The edit distance between the two strings, or -1 if one of them is null

levenshteinDistancePercent

public static double levenshteinDistancePercent(String expected,
 String actual)

Calculates the Levenshtein distance as percentage of the length of the longer string.

Parameters:

expected - the expected string

actual - the actual string

Returns:

the deviation in percent (0 for two empty strings), or -1 if one of them is null

isNameWithinDeviation

public static boolean isNameWithinDeviation(String expectedName,
 String actualName,
 int threshold)

Checks if names are within a specified deviation threshold.

Parameters:

expectedName - The expected name

actualName - The actual name

threshold - The deviation threshold in percent (0-100)

Returns:

true if the deviation is within the threshold, false otherwise

safeCast

public static Object safeCast(Object val,
 Class<?> castTo)

Converts a value to the given type: returns the value itself if it already is an instance, or converts between numeric types (e.g. an int result where a double is expected; char counts as numeric type). A numeric conversion must not change the value beyond rounding: an integral type (int, long, short, byte, char) only takes a whole number within its range (2.5 or 300 do not fit into a byte, 65 becomes 'A'); a float takes every double that does not overflow it. Fails with a readable assertion message if neither is possible.

Parameters:

val - the value to convert (must not be null)

castTo - the expected type

Returns:

the converted value

safeCast

public static Object safeCast(Object val,
 Class<?> castTo,
 boolean allowNull)

Like safeCast(Object, Class), but optionally permits null.

Parameters:

val - the value to convert

castTo - the expected type

allowNull - whether null is accepted (and returned)

Returns:

the converted value

selectWorstExistence

public static WrapperProperty.Existence selectWorstExistence(WrapperProperty.Existence worst,
 WrapperProperty.Existence updated)

Selects the worse existence state between two states, ignoring UNCHECKED. Used to aggregate multiple property existence states into a single worst-case state.

Parameters:

worst - the current worst existence state

updated - the new existence state to compare

Returns:

the worse of the two existence states

See Also:

• WrapperProperty.Existence.worst(WrapperProperty.Existence, WrapperProperty.Existence)

verifyType

public static void verifyType(WrapperProperty<Class<?>> typeWrapperProperty,
 Class<?> actualType)

Verifies that the actual type matches or is compatible with the expected type. Checks for exact match, primitive/wrapper equivalence (e.g. int vs. Integer), assignability, or numeric type containment (e.g. long can contain int). Updates the type property existence state accordingly.

Parameters:

typeWrapperProperty - the wrapper property containing the expected type

actualType - the actual type found via reflection

isNumericDeviation

public static boolean isNumericDeviation(Class<?> expected,
 Class<?> actual)

Checks whether two types are different numeric types in either direction (e.g. long vs. int, Integer vs. double). boolean and non-primitive types never qualify.

Parameters:

expected - the expected type

actual - the actual type

Returns:

true if both unwrap to numeric primitives (byte, short, char, int, long, float, double)

canContain

public static boolean canContain(Class<?> actualType,
 Class<?> expectedType)

Checks if the actual primitive type can contain the expected primitive type, i.e. whether Java's widening primitive conversion goes from the expected to the actual type. For example, a long can contain an int, a double can contain a float, and every numeric type except byte and short can contain a char.

Parameters:

actualType - the actual type to check

expectedType - the expected type to verify containment for

Returns:

true if actualType can contain values of expectedType, false otherwise

unwrapPrimitive

public static Class<?> unwrapPrimitive(Class<?> type)

Unwraps a primitive wrapper class to its corresponding primitive type. For example, Integer.class is unwrapped to int.class.

Parameters:

type - the type to unwrap

Returns:

the primitive type if type is a wrapper, otherwise the original type

toWrapperType

public static Class<?> toWrapperType(Class<?> type)

Converts a primitive type to its corresponding wrapper type. For example, int.class is converted to Integer.class.

Parameters:

type - the type to convert

Returns:

the wrapper type if type is primitive, otherwise the original type