org.srplib.reflection

Class ReflectionUtils

java.lang.Object

org.srplib.reflection.ReflectionUtils

public class ReflectionUtils
extends java.lang.Object

Helper class containing static utility methods for simplifying reflection API.

Field Summary

Fields

Modifier and Type	Field and Description
static java.lang.Object[]	EMPTY_ARGUMENTS Predeclared empty object array (new Object[0]).
static java.lang.Class<?>[]	EMPTY_TYPES Predeclared empty class array (new Class[0]).
static java.util.Set<java.lang.Class<?>>	WRAPPERS Set containing primitive wrapper classes.

Constructor Summary

Constructors

Constructor and Description
ReflectionUtils()

Method Summary

Modifier and Type	Method and Description
static <T> java.lang.Class<T>	classForName(java.lang.String className) An alternative to Class.forName(String) which wraps checked ClassNotFoundException exception into unchecked ReflectionException
static java.lang.reflect.Field	findField(java.lang.Class<?> clazz, java.lang.String fieldName) Returns declared field of specified class.
static java.lang.reflect.Field	findFieldRecursively(java.lang.Class<?> clazz, org.srplib.support.Path path) Searches field specified as Path.
static java.lang.reflect.Field	findFieldRecursively(java.lang.Class<?> clazz, java.lang.String fieldName) Searches recursively and returns declared field with specified name.
static java.lang.reflect.Method	findMethod(java.lang.Class<?> clazz, java.lang.String methodName, java.lang.Class<?>... parameters) Searches and returns specified method in specified class.
static java.lang.reflect.Method	findMethodRecursively(java.lang.Class<?> clazz, java.lang.String methodName, java.lang.Class<?>... parameters) Searches and returns specified method recursively.
static java.lang.reflect.Field	getField(java.lang.Class<?> clazz, java.lang.String fieldName) Returns declared field of specified class.
static java.lang.reflect.Field	getFieldRecursively(java.lang.Class<?> clazz, org.srplib.support.Path path) Searches recursively and returns declared field with specified name.
static java.lang.reflect.Field	getFieldRecursively(java.lang.Class<?> clazz, java.lang.String fieldName) Searches recursively and returns declared field with specified name.
static java.util.List<java.lang.reflect.Field>	getFields(java.lang.Class<?> clazz) Returns list of declared fields of specified class.
static java.util.List<java.lang.reflect.Field>	getFieldsRecursively(java.lang.Class<?> clazz) Returns list of declared fields of specified class including fields of superclasses.
static <T> java.lang.Class<T>	getFieldType(java.lang.Class<?> clazz, java.lang.String fieldName) Returns field type.
static <T> T	getFieldValue(java.lang.Object target, java.lang.reflect.Field field) Set value of specified field of specified object.
static <T> T	getFieldValue(java.lang.Object target, org.srplib.support.Path path) Returns value of nested field specified as path.
static <T> T	getFieldValue(java.lang.Object target, java.lang.String fieldName) Returns value of specified property of specified object.
static java.lang.Object	getInitValue(java.lang.Class<?> type) Returns init value for specified class (including classes representing primitives).
static java.lang.reflect.Method	getMethod(java.lang.Class<?> clazz, java.lang.String methodName, java.lang.Class<?>... parameters) Searches and returns specified method in specified class.
static java.lang.reflect.Method	getMethodRecursively(java.lang.Class<?> clazz, java.lang.String methodName, java.lang.Class<?>... parameters) Searches and returns specified method recursively.
static <T> java.lang.Class<T>	getTypeParameter(java.lang.Class<?> clazz) Returns first generic type parameter of specified class.
static <T> java.lang.Class<T>	getTypeParameter(java.lang.Class<?> clazz, java.lang.String message, java.lang.Object... parameters) Returns first generic type parameter of specified class with specific error message.
static java.util.List<java.lang.Class<?>>	getTypeParameters(java.lang.Class<?> clazz) Returns first generic type parameter of specified class.
static boolean	hasConstructor(java.lang.Class<?> clazz, java.lang.Class<?>[] parameterTypes) Checks for constructor existence.
static <T> T	invokeMethod(java.lang.reflect.Method method, java.lang.Object object, java.lang.Object... arguments) Deprecated. use invokeMethod(Object, Method, Object...)
static <T> T	invokeMethod(java.lang.Object target, java.lang.reflect.Method method, java.lang.Object... arguments) Invokes specified method of specified target using reflection.
static boolean	isArray(java.lang.Class<?> clazz) Deprecated. use Types class
static boolean	isCollection(java.lang.Class<?> clazz) Tests if specified class is a collection.
static boolean	isComplexType(java.lang.Class<?> clazz) Tests if specified class represents "complex" type.
static boolean	isMap(java.lang.Class<?> clazz) Tests if specified class is a map.
static boolean	isPrimitiveArray(java.lang.Class<?> clazz) Deprecated. use Types class
static boolean	isPrimitiveWrapper(java.lang.Class<?> clazz) Deprecated. use Types class
static boolean	isPrimitiveWrapperArray(java.lang.Class<?> clazz) Deprecated. use Types class
static boolean	isSimpleType(java.lang.Class<?> clazz) Tests if specified class represents "simple" type.
static boolean	isSyntheticName(java.lang.String name) Tests if specified name is a synthetic name.
static <T> T	newInstance(java.lang.Class<T> clazz) Creates instance of specified class and wraps checked exceptions into unchecked ones.
static <T> T	newInstance(java.lang.Class<T> clazz, java.lang.Class[] parameters, java.lang.Object[] arguments) Creates instance of specified class and wraps checked exceptions into unchecked ones.
static <T> T	newInstance(java.lang.String className) Creates instance of specified class and wraps checked exceptions into unchecked ones.
static void	setFieldValue(java.lang.Object target, java.lang.reflect.Field field, java.lang.Object value) Set value of specified field of specified object.
static void	setFieldValue(java.lang.Object target, org.srplib.support.Path path, java.lang.Object value) Set value of specified field of specified object.
static void	setFieldValue(java.lang.Object target, java.lang.String fieldName, java.lang.Object value) Set value of specified field of specified object.

Methods inherited from class java.lang.Object

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

Field Detail

EMPTY_ARGUMENTS

public static final java.lang.Object[] EMPTY_ARGUMENTS

Predeclared empty object array (new Object[0]).

EMPTY_TYPES

public static final java.lang.Class<?>[] EMPTY_TYPES

Predeclared empty class array (new Class[0]).

WRAPPERS

public static final java.util.Set<java.lang.Class<?>> WRAPPERS

Set containing primitive wrapper classes.

Constructor Detail

ReflectionUtils

public ReflectionUtils()

Method Detail

getInitValue

public static java.lang.Object getInitValue(java.lang.Class<?> type)

Returns init value for specified class (including classes representing primitives).

Parameters:

type - Class class

Returns:

null for reference types, for primitives returns their init values.

getTypeParameters

public static java.util.List<java.lang.Class<?>> getTypeParameters(java.lang.Class<?> clazz)

Returns first generic type parameter of specified class.

Parameters:

clazz - Class source class

Returns:

Class class of type parameters, null if class has no type parameters.

getTypeParameter

public static <T> java.lang.Class<T> getTypeParameter(java.lang.Class<?> clazz)

Returns first generic type parameter of specified class.

Parameters:

clazz - Class source class

Returns:

Class class of type parameters, null if class has no type parameters.

getTypeParameter

public static <T> java.lang.Class<T> getTypeParameter(java.lang.Class<?> clazz,
                                                      java.lang.String message,
                                                      java.lang.Object... parameters)

Returns first generic type parameter of specified class with specific error message.

Parameters:

clazz - Class source class

message - String error message pattern, Message will be used to construct exception text.

parameters - Object vararg. parameter for message pattern.

Returns:

Class class of type parameters, null if class has no type parameters.

findMethod

public static java.lang.reflect.Method findMethod(java.lang.Class<?> clazz,
                                                  java.lang.String methodName,
                                                  java.lang.Class<?>... parameters)

Searches and returns specified method in specified class. Non recursive.

Parameters:

clazz - Class starting class to search method in

methodName - String method name.

parameters - an array of parameter types

Returns:

Method if found, null otherwise

getMethod

public static java.lang.reflect.Method getMethod(java.lang.Class<?> clazz,
                                                 java.lang.String methodName,
                                                 java.lang.Class<?>... parameters)

Searches and returns specified method in specified class. Non recursive.

Parameters:

clazz - Class starting class to search method in

methodName - String method name.

parameters - an array of parameter types

Returns:

Method if found, null otherwise

Throws:

ReflectionException - if no method found

findMethodRecursively

public static java.lang.reflect.Method findMethodRecursively(java.lang.Class<?> clazz,
                                                             java.lang.String methodName,
                                                             java.lang.Class<?>... parameters)

Searches and returns specified method recursively.

Parameters:

clazz - Class starting class to search method in.

methodName - String method name (non-null).

parameters - an array of parameter types

Returns:

Method if found, null otherwise. Returns null if clazz is null.

getMethodRecursively

public static java.lang.reflect.Method getMethodRecursively(java.lang.Class<?> clazz,
                                                            java.lang.String methodName,
                                                            java.lang.Class<?>... parameters)

Searches and returns specified method recursively.

Parameters:

clazz - Class starting class to search method in

methodName - String method name.

parameters - an array of parameter types

Returns:

Method by specified parameters

Throws:

ReflectionException - if no method found.

findField

public static java.lang.reflect.Field findField(java.lang.Class<?> clazz,
                                                java.lang.String fieldName)

Returns declared field of specified class.

Parameters:

clazz - Class class to introspect.

Returns:

Field or null if no such field in specified class.

getField

public static java.lang.reflect.Field getField(java.lang.Class<?> clazz,
                                               java.lang.String fieldName)

Returns declared field of specified class.

Parameters:

clazz - Class class to introspect.

Returns:

Field

findFieldRecursively

public static java.lang.reflect.Field findFieldRecursively(java.lang.Class<?> clazz,
                                                           java.lang.String fieldName)

Searches recursively and returns declared field with specified name.

Parameters:

clazz - Class class to start search from

fieldName - String field name

Returns:

Field field name or null if field was not found in class or superclasses

findFieldRecursively

public static java.lang.reflect.Field findFieldRecursively(java.lang.Class<?> clazz,
                                                           org.srplib.support.Path path)

Searches field specified as Path. TODO: finder should not throw exception

Parameters:

clazz - Class class

Returns:

path Path field path

Throws:

java.lang.IllegalArgumentException - if class or path is null

ReflectionException - if intermediate field is not found

getFieldRecursively

public static java.lang.reflect.Field getFieldRecursively(java.lang.Class<?> clazz,
                                                          org.srplib.support.Path path)

Searches recursively and returns declared field with specified name.

Parameters:

clazz - Class class to start search from

path - Path field path

Returns:

Field field name or null if field was not found in class or superclasses

Throws:

ReflectionException - if no such field found

getFieldRecursively

public static java.lang.reflect.Field getFieldRecursively(java.lang.Class<?> clazz,
                                                          java.lang.String fieldName)

Searches recursively and returns declared field with specified name.

Parameters:

clazz - Class class to start search from

fieldName - String field name

Returns:

Field field name or null if field was not found in class or superclasses

Throws:

ReflectionException - if no such field found

getFields

public static java.util.List<java.lang.reflect.Field> getFields(java.lang.Class<?> clazz)

Returns list of declared fields of specified class.

Parameters:

clazz - Class class to introspect.

Returns:

List of Field

getFieldsRecursively

public static java.util.List<java.lang.reflect.Field> getFieldsRecursively(java.lang.Class<?> clazz)

Returns list of declared fields of specified class including fields of superclasses.

Parameters:

clazz - Class class to introspect.

Returns:

List of Field

setFieldValue

public static void setFieldValue(java.lang.Object target,
                                 java.lang.reflect.Field field,
                                 java.lang.Object value)

Set value of specified field of specified object.

Method wraps all checked exceptions into unchecked exceptions.

Parameters:

target - Object the object the underlying method is invoked from

field - Field field to set value to.

value - Object value to set to field

Throws:

ReflectionException - if can't set field value.

setFieldValue

public static void setFieldValue(java.lang.Object target,
                                 java.lang.String fieldName,
                                 java.lang.Object value)

Set value of specified field of specified object.

Method wraps all checked exceptions into unchecked exceptions.

Parameters:

target - Object target object

fieldName - String field name to set value to.

value - Object value to set to a field

Throws:

ReflectionException - if can't set field value.

setFieldValue

public static void setFieldValue(java.lang.Object target,
                                 org.srplib.support.Path path,
                                 java.lang.Object value)

Set value of specified field of specified object.

Parameters:

target - Object target object

path - Path field path

value - Object value to set to field

Throws:

java.lang.IllegalArgumentException - if target of path are null

ReflectionException - in case of reflection error

getFieldValue

public static <T> T getFieldValue(java.lang.Object target,
                                  java.lang.reflect.Field field)

Set value of specified field of specified object.

Method wraps all checked exceptions into unchecked exceptions.

Parameters:

target - Object target object

field - Field field to set value to.

Returns:

value of field

Throws:

ReflectionException - if can't get field value.

getFieldValue

public static <T> T getFieldValue(java.lang.Object target,
                                  java.lang.String fieldName)

Returns value of specified property of specified object.

Method wraps all checked exceptions into unchecked exceptions.

Parameters:

target - Object target object

fieldName - String field name

Returns:

value of specified property

Throws:

ReflectionException - if can't get field value.

getFieldValue

public static <T> T getFieldValue(java.lang.Object target,
                                  org.srplib.support.Path path)

Returns value of nested field specified as path.

Parameters:

target - Object target object.

path - Path field path

Returns:

Object field value

Throws:

java.lang.IllegalArgumentException - if target or path are null

ReflectionException - if case of reflection error

getFieldType

public static <T> java.lang.Class<T> getFieldType(java.lang.Class<?> clazz,
                                                  java.lang.String fieldName)

Returns field type.

Parameters:

clazz - Class a class where field is declared

fieldName - String field name

Returns:

Class return field type

Throws:

java.lang.IllegalStateException - if no such field in specified class

invokeMethod

@Deprecated
public static <T> T invokeMethod(java.lang.reflect.Method method,
                                             java.lang.Object object,
                                             java.lang.Object... arguments)

Deprecated. use invokeMethod(Object, Method, Object...)

Invokes specified method of specified object using reflection.

Method wraps all checked exceptions into unchecked exceptions.

Parameters:

method - Method to invoke

object - Object the object the underlying method is invoked from

arguments - vararg array of method arguments.

Returns:

method invocation result

invokeMethod

public static <T> T invokeMethod(java.lang.Object target,
                                 java.lang.reflect.Method method,
                                 java.lang.Object... arguments)

Invokes specified method of specified target using reflection.

Method wraps all checked exceptions into unchecked exceptions.

Parameters:

method - Method to invoke

target - Object the target the underlying method is invoked from

arguments - vararg array of method arguments.

Returns:

method invocation result

newInstance

public static <T> T newInstance(java.lang.Class<T> clazz,
                                java.lang.Class[] parameters,
                                java.lang.Object[] arguments)

Creates instance of specified class and wraps checked exceptions into unchecked ones.

Converts checked exceptions to unchecked

Parameters:

clazz - Class a class to create instance

parameters - Class[] array of constructor parameters (parameter types).

arguments - Object[] an array of constructor arguments.

Returns:

an instance of specified class

newInstance

public static <T> T newInstance(java.lang.Class<T> clazz)

Creates instance of specified class and wraps checked exceptions into unchecked ones.

Converts checked exceptions to unchecked

Parameters:

clazz - Class a class to create instance

Returns:

an instance of specified class

newInstance

public static <T> T newInstance(java.lang.String className)

Creates instance of specified class and wraps checked exceptions into unchecked ones.

Converts checked exceptions to unchecked

Parameters:

className - String class name of a class to create instance

Returns:

an instance of specified class

hasConstructor

public static boolean hasConstructor(java.lang.Class<?> clazz,
                                     java.lang.Class<?>[] parameterTypes)

Checks for constructor existence.

Returns:

true if specified class has constructor with specified parameter parameters.

classForName

public static <T> java.lang.Class<T> classForName(java.lang.String className)

An alternative to Class.forName(String) which wraps checked ClassNotFoundException exception into unchecked ReflectionException

Parameters:

className - String full class name

Returns:

Class class for specified name

Throws:

java.lang.IllegalArgumentException - if class name is null.

ReflectionException - if reflection API throws ClassNotFoundException

isArray

public static boolean isArray(java.lang.Class<?> clazz)

Deprecated. use Types class

Tests if specified class is an array.

Parameters:

clazz - Class a class to test

Returns:

true if class is an array

Throws:

java.lang.IllegalArgumentException - if the specified Class parameter is null.

isCollection

public static boolean isCollection(java.lang.Class<?> clazz)

Tests if specified class is a collection.

Parameters:

clazz - Class a class to test

Returns:

true if class is a collection

Throws:

java.lang.IllegalArgumentException - if the specified Class parameter is null.

isMap

public static boolean isMap(java.lang.Class<?> clazz)

Tests if specified class is a map.

Parameters:

clazz - Class a class to test

Returns:

true if class is a map

Throws:

java.lang.IllegalArgumentException - if the specified Class parameter is null.

isSimpleType

public static boolean isSimpleType(java.lang.Class<?> clazz)

Tests if specified class represents "simple" type.

Simple types are:
• classes representing primitives (int.class, long.class, etc.)
• primitive wrapper classes
• String
• Date
• Enum

Parameters:

clazz - Class a class to test

Returns:

true if class represents simple type

Throws:

java.lang.IllegalArgumentException - if the specified Class parameter is null.

isComplexType

public static boolean isComplexType(java.lang.Class<?> clazz)

Tests if specified class represents "complex" type.

Complex type is a type which is not simple (see isSimpleType(Class)).

Parameters:

clazz - Class a class to test

Returns:

true if class is complex class

Throws:

java.lang.IllegalArgumentException - if the specified Class parameter is null.

isSyntheticName

public static boolean isSyntheticName(java.lang.String name)

Tests if specified name is a synthetic name.

Parameters:

name - String identifier name

Returns:

true if name contains dollar sign, false if null or doesn't contain dollar sign.

isPrimitiveWrapper

public static boolean isPrimitiveWrapper(java.lang.Class<?> clazz)

Deprecated. use Types class

Tests if specified class is a primitive wrapper.

Primitive wrappers are listed in WRAPPERS set.

Parameters:

clazz - Class a class to test

Returns:

true if class is primitive wrapper

isPrimitiveArray

public static boolean isPrimitiveArray(java.lang.Class<?> clazz)

Deprecated. use Types class

Tests if specified class is an array of primitives.

Parameters:

clazz - Class a class to test

Returns:

true if class is an array of primitives

Throws:

java.lang.IllegalArgumentException - if the specified Class parameter is null.

isPrimitiveWrapperArray

public static boolean isPrimitiveWrapperArray(java.lang.Class<?> clazz)

Deprecated. use Types class

Tests if specified class is an array of primitive wrapper.

Parameters:

clazz - Class a class to test

Returns:

true if class is an array

Throws:

java.lang.IllegalArgumentException - if the specified Class parameter is null.