Reflection (OmniFaces 3.1 API)

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

All Methods Static Methods Concrete Methods
Modifier and Type	Method and Description
`static <T> T`	`accessField(Object instance, String fieldName)` Returns the value of the field of the given instance on the given field name.
`static <T> Constructor<T>`	`findConstructor(Class<T> clazz, Class<?>... parameterTypes)` Finds a constructor based on the given parameter types and returns `null` is none is found.
`static Method`	`findMethod(Object base, String methodName, Object... params)` Finds a method based on the method name, amount of parameters and limited typing and returns `null` is none is found.
`static <T> T`	`instance(Class<T> clazz)` Returns a new instance of the given class object using the default constructor.
`static <T> T`	`instance(String className)` Returns a new instance of the given class name using the default constructor.
`static <T> T`	`invokeMethod(Object instance, String methodName, Object... parameters)` Invoke a method of the given instance on the given method name with the given parameters and return the result.
`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 <T> Class<T>`	`toClass(String className)` Returns the class object associated with the given class name, using the context class loader and if that fails the defining class loader of the current class.
`static <T> Class<T>`	`toClassOrNull(String className)` Returns the class object associated with the given class name, 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 and returns null is none is found.
    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 <T> Class<T> toClass(String className)
```
    Returns the class object associated with the given class name, using the context class loader and if that fails the defining class loader of the current class.
    
    Type Parameters:
    
    T - The expected class type.
    
    Parameters:
    
    className - Fully qualified class name of the class for which a class object needs to be created.
    
    Returns:
    
    The class object associated with the given class name.
    
    Throws:
    
    IllegalStateException - If the class cannot be loaded.
    
    ClassCastException - When T is of wrong type.
  - toClassOrNull
```
public static <T> Class<T> toClassOrNull(String className)
```
    Returns the class object associated with the given class name, using the context class loader and if that fails the defining class loader of the current class. If the class cannot be loaded, then return null instead of throwing illegal state exception.
    
    Type Parameters:
    
    T - The expected class type.
    
    Parameters:
    
    className - Fully qualified class name of the class for which a class object needs to be created.
    
    Returns:
    
    The class object associated with the given class name.
    
    Throws:
    
    ClassCastException - When T is of wrong type.
    
    Since:
    
    2.5
  - findConstructor
```
public static <T> Constructor<T> findConstructor(Class<T> clazz,
                                                 Class<?>... parameterTypes)
```
    Finds a constructor based on the given parameter types and returns null is none is found.
    
    Parameters:
    
    clazz - The class object for which the constructor is to be found.
    
    parameterTypes - The desired method parameter types.
    
    Returns:
    
    A constructor if one is found, null otherwise.
    
    Since:
    
    2.6
  - instance
```
public static <T> T instance(String className)
```
    Returns a new instance of the given class name using the default constructor.
    
    Type Parameters:
    
    T - The expected return type.
    
    Parameters:
    
    className - Fully qualified class name of the class for which an instance needs to be created.
    
    Returns:
    
    A new instance of the given class name using the default constructor.
    
    Throws:
    
    IllegalStateException - If the class cannot be loaded.
    
    ClassCastException - When T is of wrong type.
  - instance
```
public static <T> T instance(Class<T> clazz)
```
    Returns a new instance of the given class object using the default constructor.
    
    Type Parameters:
    
    T - The generic object type.
    
    Parameters:
    
    clazz - The class object for which an instance needs to be created.
    
    Returns:
    
    A new instance of the given class object using the default constructor.
    
    Throws:
    
    IllegalStateException - If the class cannot be found, or cannot be instantiated, or when a security manager prevents this operation.
  - accessField
```
public static <T> T accessField(Object instance,
                                String fieldName)
```
    Returns the value of the field of the given instance on the given field name.
    
    Type Parameters:
    
    T - The expected return type.
    
    Parameters:
    
    instance - The instance to access the given field on.
    
    fieldName - The name of the field to be accessed on the given instance.
    
    Returns:
    
    The value of the field of the given instance on the given field name.
    
    Throws:
    
    ClassCastException - When T is of wrong type.
    
    IllegalStateException - If the field cannot be accessed.
    
    Since:
    
    2.5
  - invokeMethod
```
public static <T> T invokeMethod(Object instance,
                                 String methodName,
                                 Object... parameters)
```
    Invoke a method of the given instance on the given method name with the given parameters and return the result.
    Note: the current implementation assumes for simplicity that no one of the given parameters is null. If one of them is still null, a NullPointerException will be thrown.
    
    Type Parameters:
    
    T - The expected return type.
    
    Parameters:
    
    instance - The instance to invoke the given method on.
    
    methodName - The name of the method to be invoked on the given instance.
    
    parameters - The method parameters, if any.
    
    Returns:
    
    The result of the method invocation, if any.
    
    Throws:
    
    NullPointerException - When one of the given parameters is null.
    
    IllegalStateException - If the method cannot be invoked.
    
    ClassCastException - When T is of wrong type.
    
    Since:
    
    2.5

Class Reflection

Method Summary

Methods inherited from class java.lang.Object

Method Detail

setProperties

setPropertiesWithCoercion

findMethod

toClass

toClassOrNull

findConstructor

instance

instance

accessField

invokeMethod