org.omnifaces.util

Class Reflection

java.lang.Object

org.omnifaces.util.Reflection

@Typed
public final class Reflection
extends Object

Collection of utility methods for working with reflection.

Since:

2.0

Author:

Arjan Tijms

Method Summary

Modifier and Type	Method and Description
static Method	findMethod(Object base, String methodName, Object[] params) Finds a method based on the method name, amount of parameters and limited typing.
static <T> T	instance(Class<T> clazz) Creates a new instance of the class represented by the given Class object
static <T> T	instance(String className) Creates an instance of a class with the given fully qualified class name.
static void	setProperties(Object object, Map<String,Object> propertiesToSet) Sets a collection of properties of a given object to the values associated with those properties.
static void	setPropertiesWithCoercion(Object object, Map<String,Object> propertiesToSet) Sets a collection of properties of a given object to the (optionally coerced) values associated with those properties.
static Class<?>	toClass(String className) Returns the Class instance associated with the class of the given string, using the context class loader and if that fails the defining class loader of the current class.

Methods inherited from class java.lang.Object

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

Method Detail

setProperties

public static void setProperties(Object object,
                                 Map<String,Object> propertiesToSet)

Sets a collection of properties of a given object to the values associated with those properties.

In the map that represents these properties, each key represents the name of the property, with the value associated with that key being the value that is set for the property.

E.g. map entry key = foo, value = "bar", which "bar" an instance of String, will conceptually result in the following call: object.setFoo("string");

NOTE: This particular method assumes that there's a write method for each property in the map with the right type. No specific checking is done whether this is indeed the case.

Parameters:

object - the object on which properties will be set

propertiesToSet - the map containing properties and their values to be set on the object

setPropertiesWithCoercion

public static void setPropertiesWithCoercion(Object object,
                                             Map<String,Object> propertiesToSet)

Sets a collection of properties of a given object to the (optionally coerced) values associated with those properties.

In the map that represents these properties, each key represents the name of the property, with the value associated with that key being the value that is set for the property.

E.g. map entry key = foo, value = "bar", which "bar" an instance of String, will conceptually result in the following call: object.setFoo("string");

NOTE 1: In case the value is a String, and the target type is not String, the standard property editor mechanism will be used to attempt a conversion.

Note 2: This method operates somewhat as the reverse of setProperties(Object, Map). Here only the available writable properties of the object are matched against the map with properties to set. Properties in the map for which there isn't a corresponding writable property on the object are ignored.

Following the above two notes, use this method when attempting to set properties on an object in a lenient best effort basis. Use setProperties(Object, Map) when all properties need to be set with the exact type as the value appears in the map.

Parameters:

object - the object on which properties will be set

propertiesToSet - the map containing properties and their values to be set on the object

findMethod

public static Method findMethod(Object base,
                                String methodName,
                                Object[] params)

Finds a method based on the method name, amount of parameters and limited typing.

Note that this supports overloading, but a limited one. Given an actual parameter of type Long, this will select a method accepting Number when the choice is between Number and a non-compatible type like String. However, it will NOT select the best match if the choice is between Number and Long.

Parameters:

base - the object in which the method is to be found

methodName - name of the method to be found

params - the method parameters

Returns:

a method if one is found, null otherwise

toClass

public static Class<?> toClass(String className)

Returns the Class instance associated with the class of the given string, using the context class loader and if that fails the defining class loader of the current class.

Parameters:

className - fully qualified class name of the class for which a Class instance needs to be created

Returns:

the Class object for the class with the given name.

Throws:

IllegalStateException - if the class cannot be found.

instance

public static <T> T instance(String className)

Creates an instance of a class with the given fully qualified class name.

Type Parameters:

T - The generic object type.

Parameters:

className - fully qualified class name of the class for which an instance needs to be created

Returns:

an instance of the class denoted by className

Throws:

IllegalStateException - if the class cannot be found

instance

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

Creates a new instance of the class represented by the given Class object

Type Parameters:

T - The generic object type.

Parameters:

clazz - the Class object for which an instance needs to be created

Returns:

an instance of the class as given by the clazz parameter

Throws:

IllegalStateException - if the class cannot be found, or cannot be instantiated or when a security manager prevents this operation