Class Utils

java.lang.Object

com.blackrook.archetext.struct.Utils

public final class Utils
extends Object

Constructor Summary

Constructors

Constructor	Description
Utils()

Method Summary

Modifier and Type	Method	Description
static <T> T	applyToObject(ArcheTextObject atObject, T object)	Applies this object to an object bean / plain ol' Java object.
static <T> T	construct(Constructor<T> constructor, Object... params)	Creates a new instance of a class from a class type.
static <T> T	create(Class<T> clazz)	Creates a new instance of a class from a class type.
static <T> T	createForType(Object object, Class<T> targetType)	Reflect.creates a new instance of an object for placement in a POJO or elsewhere.
static <T, S extends Set<T>> S	difference(S set1, S set2)	Returns a new Set that is the difference of the objects in two sets, i.e.
static <T> void	exportTo(T object, ArcheTextObject atext)	Exports the values of an object to an ArcheTextObject.
static int	getArrayDimensions(Class<?> arrayType)	Gets how many dimensions that this array, represented by the provided type, has.
static int	getArrayDimensions(Object array)	Gets how many array dimensions that an object (presumably an array) has.
static Class<?>	getArrayType(Class<?> arrayType)	Gets the class type of this array type, if this is an array type.
static Class<?>	getArrayType(Object object)	Gets the class type of this array, if this is an array.
static Object	getFieldValue(Object instance, Field field)	Gets the value of a field on an object.
static <T> String	getIdentityFromObject(T object)	Get identity name for object.
static <T, S extends Set<T>> S	intersection(S set1, S set2)	Returns a new Set that is the intersection of the objects in two sets, i.e.
static Object	invokeBlind(Method method, Object instance, Object... params)	Blindly invokes a method, only throwing a RuntimeException if something goes wrong.
static boolean	isArray(Class<?> clazz)	Tests if a class is actually an array type.
static boolean	isArray(Object object)	Tests if an object is actually an array type.
static boolean	isEmpty(Object obj)	Checks if a value is "empty." The following is considered "empty": Null references.
static <T> T	isNull(T testObject, T nullReturn)	Returns the first object if it is not null, otherwise returns the second.
static boolean	isWindows()
static InputStream	openResource(String pathString)	Opens an InputStream to a resource using the current thread's ClassLoader.
static void	setFieldValue(Object instance, Field field, Object value)	Sets the value of a field on an object.
static <T, S extends Set<T>> S	union(S set1, S set2)	Returns a new Set that is the union of the objects in two sets, i.e.
static <T, S extends Set<T>> S	xor(S set1, S set2)	Returns a new Set that is the union minus the intersection of the objects in two sets.

Methods inherited from class Object

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

Constructor Details

Utils

public Utils()

Method Details

isWindows

public static boolean isWindows()

Returns:

true if we using Windows.

createForType

public static <T> T createForType(Object object,
 Class<T> targetType)

Reflect.creates a new instance of an object for placement in a POJO or elsewhere.

Type Parameters:

T - the return object type.

Parameters:

object - the object to convert to another object

targetType - the target class type to convert to, if the types differ.

Returns:

a suitable object of type targetType.

Throws:

ClassCastException - if the incoming type cannot be converted.

openResource

public static InputStream openResource(String pathString)

Opens an InputStream to a resource using the current thread's ClassLoader.

Parameters:

pathString - the resource pathname.

Returns:

an open InputStream for reading the resource or null if not found.

See Also:

• ClassLoader.getResourceAsStream(String)

isArray

public static boolean isArray(Class<?> clazz)

Tests if a class is actually an array type.

Parameters:

clazz - the class to test.

Returns:

true if so, false if not.

isArray

public static boolean isArray(Object object)

Tests if an object is actually an array type.

Parameters:

object - the object to test.

Returns:

true if so, false if not.

getArrayDimensions

public static int getArrayDimensions(Class<?> arrayType)

Gets how many dimensions that this array, represented by the provided type, has.

Parameters:

arrayType - the type to inspect.

Returns:

the number of array dimensions, or 0 if not an array.

getArrayDimensions

public static int getArrayDimensions(Object array)

Gets how many array dimensions that an object (presumably an array) has.

Parameters:

array - the object to inspect.

Returns:

the number of array dimensions, or 0 if not an array.

getArrayType

public static Class<?> getArrayType(Class<?> arrayType)

Gets the class type of this array type, if this is an array type.

Parameters:

arrayType - the type to inspect.

Returns:

this array's type, or null if the provided type is not an array, or if the found class is not on the classpath.

getArrayType

public static Class<?> getArrayType(Object object)

Gets the class type of this array, if this is an array.

Parameters:

object - the object to inspect.

Returns:

this array's type, or null if the provided object is not an array, or if the found class is not on the classpath.

isEmpty

public static boolean isEmpty(Object obj)

Checks if a value is "empty." The following is considered "empty":

• Null references.
• Array objects that have a length of 0.
• Boolean objects that are false.
• Character objects that are the null character ('\0', '').
• Number objects that are zero.
• String objects that are the empty string, or are String.trim()'ed down to the empty string.
• Collection objects where Collection.isEmpty() returns true.

Parameters:

obj - the object to check.

Returns:

true if the provided object is considered "empty", false otherwise.

isNull

public static <T> T isNull(T testObject,
 T nullReturn)

Returns the first object if it is not null, otherwise returns the second.

Type Parameters:

T - class that extends Object.

Parameters:

testObject - the first ("tested") object.

nullReturn - the object to return if testObject is null.

Returns:

testObject if not null, nullReturn otherwise.

union

public static <T, S extends Set<T>> S union(S set1,
 S set2)

Returns a new Set that is the union of the objects in two sets, i.e. a set with all objects from both sets.

Type Parameters:

T - the object type in the provided set.

S - the set that contains type T.

Parameters:

set1 - the first set.

set2 - the second set.

Returns:

a new set.

intersection

public static <T, S extends Set<T>> S intersection(S set1,
 S set2)

Returns a new Set that is the intersection of the objects in two sets, i.e. the objects that are present in both sets.

Type Parameters:

T - the object type in the provided set.

S - the set table that contains type T.

Parameters:

set1 - the first set.

set2 - the second set.

Returns:

a new set.

difference

public static <T, S extends Set<T>> S difference(S set1,
 S set2)

Returns a new Set that is the difference of the objects in two sets, i.e. the objects in the first set minus the objects in the second.

Type Parameters:

T - the object type in the provided set.

S - the set table that contains type T.

Parameters:

set1 - the first set.

set2 - the second set.

Returns:

a new set.

xor

public static <T, S extends Set<T>> S xor(S set1,
 S set2)

Returns a new Set that is the union minus the intersection of the objects in two sets.

Type Parameters:

T - the object type in the provided set.

S - the set table that contains type T.

Parameters:

set1 - the first set.

set2 - the second set.

Returns:

a new set.

setFieldValue

public static void setFieldValue(Object instance,
 Field field,
 Object value)

Sets the value of a field on an object.

Parameters:

instance - the object instance to set the field on.

field - the field to set.

value - the value to set.

Throws:

NullPointerException - if the field or object provided is null.

ClassCastException - if the value could not be cast to the proper type.

RuntimeException - if anything goes wrong (bad field name, bad target, bad argument, or can't access the field).

See Also:

• Field.set(Object, Object)

getFieldValue

public static Object getFieldValue(Object instance,
 Field field)

Gets the value of a field on an object.

Parameters:

instance - the object instance to get the field value of.

field - the field to get the value of.

Returns:

the current value of the field.

Throws:

NullPointerException - if the field or object provided is null.

RuntimeException - if anything goes wrong (bad target, bad argument, or can't access the field).

See Also:

• Field.set(Object, Object)

invokeBlind

public static Object invokeBlind(Method method,
 Object instance,
 Object... params)

Blindly invokes a method, only throwing a RuntimeException if something goes wrong. Here for the convenience of not making a billion try/catch clauses for a method invocation.

Parameters:

method - the method to invoke.

instance - the object instance that is the method target.

params - the parameters to pass to the method.

Returns:

the return value from the method invocation. If void, this is null.

Throws:

ClassCastException - if one of the parameters could not be cast to the proper type.

RuntimeException - if anything goes wrong (bad target, bad argument, or can't access the method).

See Also:

• Method.invoke(Object, Object...)

create

public static <T> T create(Class<T> clazz)

Creates a new instance of a class from a class type. This essentially calls Class.newInstance(), but wraps the call in a try/catch block that only throws an exception if something goes wrong.

Type Parameters:

T - the return object type.

Parameters:

clazz - the class type to instantiate.

Returns:

a new instance of an object.

Throws:

RuntimeException - if instantiation cannot happen, either due to a non-existent constructor or a non-visible constructor.

construct

public static <T> T construct(Constructor<T> constructor,
 Object... params)

Creates a new instance of a class from a class type. This essentially calls Class.newInstance(), but wraps the call in a try/catch block that only throws an exception if something goes wrong.

Type Parameters:

T - the return object type.

Parameters:

constructor - the constructor to call.

params - the constructor parameters.

Returns:

a new instance of an object created via the provided constructor.

Throws:

RuntimeException - if instantiation cannot happen, either due to a non-existent constructor or a non-visible constructor.

exportTo

public static <T> void exportTo(T object,
 ArcheTextObject atext)

Exports the values of an object to an ArcheTextObject.

Type Parameters:

T - the object's type.

Parameters:

object - the object to export.

atext - the destination structure.

Throws:

ArcheTextExportException - if a problem happens during export.

ClassCastException - if a value cannot be converted.

applyToObject

public static <T> T applyToObject(ArcheTextObject atObject,
 T object)

Applies this object to an object bean / plain ol' Java object.

This object is applied via the target object's public fields and setter methods.

For instance, if there is a member on this object called "color", its value will be applied via the public field "color" or the setter "setColor()". Public fields take precedence over setters.

Type Parameters:

T - the object's type.

Parameters:

atObject - the source object.

object - the target object.

Returns:

the applied object itself.

getIdentityFromObject

public static <T> String getIdentityFromObject(T object)

Get identity name for object.

Type Parameters:

T - the object type.

Parameters:

object - the object to inspect.

Returns:

the identity of the object to use for the ArcheText object.