org.apache.deltaspike.data.impl.property

Class Reflections

java.lang.Object

org.apache.deltaspike.data.impl.property.Reflections

public class Reflections
extends Object

Utility class for working with JDK Reflection and also CDI's Annotated metadata.

Method Summary

Methods

Modifier and Type	Method and Description
static <T> T	cast(Object obj) Perform a runtime cast.
static Method	findDeclaredMethod(Class<?> clazz, String name, Class<?>... args) Search the class hierarchy for a method with the given name and arguments.
static Set<Method>	getAllDeclaredMethods(Class<?> clazz) Get all the declared methods on the class hierarchy.
static Object	getFieldValue(Field field, Object instance)
static <T> T	getFieldValue(Field field, Object instance, Class<T> expectedType) Get the value of the field, on the specified instance, casting the value of the field to the expected type.
static String	getPropertyName(Method method) Gets the property name from a getter method.
static <T> T	invokeMethod(boolean setAccessible, Method method, Class<T> expectedReturnType, Object instance, Object... args) Invoke the method on the instance, with any arguments specified, casting the result of invoking the method to the expected return type.
static Object	invokeMethod(boolean setAccessible, Method method, Object instance, Object... args) Invoke the specified method on the provided instance, passing any additional arguments included in this method as arguments to the specified method.
static <T> T	invokeMethod(Method method, Class<T> expectedReturnType, Object instance, Object... args) Invoke the specified method on the provided instance, passing any additional arguments included in this method as arguments to the specified method.
static Object	invokeMethod(Method method, Object instance, Object... args) Invoke the specified method on the provided instance, passing any additional arguments included in this method as arguments to the specified method.
static boolean	isSerializable(Class<?> clazz) Check if a class is serializable.
static boolean	methodExists(Class<?> clazz, String name) Determine if a method exists in a specified class hierarchy
static <A extends AccessibleObject> A	setAccessible(A member) Set the accessibility flag on the AccessibleObject as described in AccessibleObject.setAccessible(boolean) within the context of a PrivilegedAction.
static void	setFieldValue(boolean setAccessible, Field field, Object instance, Object value) Sets the value of a field on the instance to the specified value.
static void	setFieldValue(Field field, Object instance, Object value) Set the value of a field on the instance to the specified value.

Methods inherited from class java.lang.Object

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

Method Detail

cast

public static <T> T cast(Object obj)

Perform a runtime cast. Similar to Class.cast(Object), but useful when you do not have a Class object for type you wish to cast to.

Class.cast(Object) should be used if possible

Type Parameters:

T - the type to cast to

Parameters:

obj - the object to perform the cast on

Returns:

the casted object

Throws:

ClassCastException - if the type T is not a subtype of the object

See Also:

Class.cast(Object)

methodExists

public static boolean methodExists(Class<?> clazz,
                   String name)

Determine if a method exists in a specified class hierarchy

Parameters:

clazz - The class to search

name - The name of the method

Returns:

true if a method is found, otherwise false

getAllDeclaredMethods

public static Set<Method> getAllDeclaredMethods(Class<?> clazz)

Get all the declared methods on the class hierarchy. This will return overridden methods.

Parameters:

clazz - The class to search

Returns:

the set of all declared methods or an empty set if there are none

findDeclaredMethod

public static Method findDeclaredMethod(Class<?> clazz,
                        String name,
                        Class<?>... args)

Search the class hierarchy for a method with the given name and arguments. Will return the nearest match, starting with the class specified and searching up the hierarchy.

Parameters:

clazz - The class to search

name - The name of the method to search for

args - The arguments of the method to search for

Returns:

The method found, or null if no method is found

setAccessible

public static <A extends AccessibleObject> A setAccessible(A member)

Set the accessibility flag on the AccessibleObject as described in AccessibleObject.setAccessible(boolean) within the context of a PrivilegedAction.

Type Parameters:

A - member the accessible object type

Parameters:

member - the accessible object

Returns:

the accessible object after the accessible flag has been altered

invokeMethod

public static Object invokeMethod(Method method,
                  Object instance,
                  Object... args)

Invoke the specified method on the provided instance, passing any additional arguments included in this method as arguments to the specified method.

This method provides the same functionality and throws the same exceptions as invokeMethod(boolean, Method, Class, Object, Object...), with the expected return type set to Object and no change to the method's accessibility.

See Also:

invokeMethod(boolean, Method, Class, Object, Object...), Method.invoke(Object, Object...)

invokeMethod

public static Object invokeMethod(boolean setAccessible,
                  Method method,
                  Object instance,
                  Object... args)

Invoke the specified method on the provided instance, passing any additional arguments included in this method as arguments to the specified method.

This method attempts to set the accessible flag of the method in a PrivilegedAction before invoking the method if the first argument is true.

This method provides the same functionality and throws the same exceptions as invokeMethod(boolean, Method, Class, Object, Object...), with the expected return type set to Object.

See Also:

invokeMethod(boolean, Method, Class, Object, Object...), Method.invoke(Object, Object...)

invokeMethod

public static <T> T invokeMethod(Method method,
                 Class<T> expectedReturnType,
                 Object instance,
                 Object... args)

Invoke the specified method on the provided instance, passing any additional arguments included in this method as arguments to the specified method.

This method provides the same functionality and throws the same exceptions as invokeMethod(boolean, Method, Class, Object, Object...), with the expected return type set to Object and honoring the accessibility of the method.

See Also:

invokeMethod(boolean, Method, Class, Object, Object...), Method.invoke(Object, Object...)

invokeMethod

public static <T> T invokeMethod(boolean setAccessible,
                 Method method,
                 Class<T> expectedReturnType,
                 Object instance,
                 Object... args)

Invoke the method on the instance, with any arguments specified, casting the result of invoking the method to the expected return type.

This method wraps Method.invoke(Object, Object...), converting the checked exceptions that Method.invoke(Object, Object...) specifies to runtime exceptions.

If instructed, this method attempts to set the accessible flag of the method in a PrivilegedAction before invoking the method.

Parameters:

setAccessible - flag indicating whether method should first be set as accessible

method - the method to invoke

instance - the instance to invoke the method

args - the arguments to the method

Returns:

the result of invoking the method, or null if the method's return type is void

Throws:

RuntimeException - if this Method object enforces Java language access control and the underlying method is inaccessible or if the underlying method throws an exception or if the initialization provoked by this method fails.

IllegalArgumentException - if the method is an instance method and the specified instance argument is not an instance of the class or interface declaring the underlying method (or of a subclass or implementor thereof); if the number of actual and formal parameters differ; if an unwrapping conversion for primitive arguments fails; or if, after possible unwrapping, a parameter value cannot be converted to the corresponding formal parameter type by a method invocation conversion.

NullPointerException - if the specified instance is null and the method is an instance method.

ClassCastException - if the result of invoking the method cannot be cast to the expectedReturnType

ExceptionInInitializerError - if the initialization provoked by this method fails.

See Also:

Method.invoke(Object, Object...)

setFieldValue

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

Set the value of a field on the instance to the specified value.

This method provides the same functionality and throws the same exceptions as Reflections#setFieldValue(boolean, Method, Class, Object, Object...), honoring the accessibility of the field.

setFieldValue

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

Sets the value of a field on the instance to the specified value.

This method wraps Field.set(Object, Object), converting the checked exceptions that Field.set(Object, Object) specifies to runtime exceptions.

If instructed, this method attempts to set the accessible flag of the method in a PrivilegedAction before invoking the method.

Parameters:

field - the field on which to operate, or null if the field is static

instance - the instance on which the field value should be set upon

value - the value to set the field to

Throws:

RuntimeException - if the underlying field is inaccessible.

IllegalArgumentException - if the specified instance is not an instance of the class or interface declaring the underlying field (or a subclass or implementor thereof), or if an unwrapping conversion fails.

NullPointerException - if the specified instance is null and the field is an instance field.

ExceptionInInitializerError - if the initialization provoked by this method fails.

See Also:

Field.set(Object, Object)

getFieldValue

public static Object getFieldValue(Field field,
                   Object instance)

getFieldValue

public static <T> T getFieldValue(Field field,
                  Object instance,
                  Class<T> expectedType)

Get the value of the field, on the specified instance, casting the value of the field to the expected type.

This method wraps Field.get(Object), converting the checked exceptions that Field.get(Object) specifies to runtime exceptions.

Type Parameters:

T - the type of the field's value

Parameters:

field - the field to operate on

instance - the instance from which to retrieve the value

expectedType - the expected type of the field's value

Returns:

the value of the field

Throws:

RuntimeException - if the underlying field is inaccessible.

IllegalArgumentException - if the specified instance is not an instance of the class or interface declaring the underlying field (or a subclass or implementor thereof).

NullPointerException - if the specified instance is null and the field is an instance field.

ExceptionInInitializerError - if the initialization provoked by this method fails.

isSerializable

public static boolean isSerializable(Class<?> clazz)

Check if a class is serializable.

Parameters:

clazz - The class to check

Returns:

true if the class implements serializable or is a primitive

getPropertyName

public static String getPropertyName(Method method)

Gets the property name from a getter method.

We extend JavaBean conventions, allowing the getter method to have parameters

Parameters:

method - The getter method

Returns:

The name of the property. Returns null if method wasn't JavaBean getter-styled