Package org.codehaus.plexus.util.reflection

Class Reflector

java.lang.Object

org.codehaus.plexus.util.reflection.Reflector

public final class Reflector
extends Object

Utility class used to instantiate an object using reflection. This utility hides many of the gory details needed to do this.

Author:

John Casey

Constructor Summary

Constructors

Constructor	Description
Reflector()	Ensure no instances of Reflector are created...this is a utility.

Method Summary

Modifier and Type	Method	Description
<T> Constructor<T>	getConstructor(Class<T> targetClass, Class[] params)	Return the constructor, checking the cache first and storing in cache if not already there..
Object	getField(Object target, String fieldName)
Object	getField(Object target, String fieldName, boolean breakAccessibility)
Method	getMethod(Class targetClass, String methodName, Class[] params)	Return the method, checking the cache first and storing in cache if not already there..
Object	getObjectProperty(Object target, String propertyName)
<T> T	getSingleton(Class<T> theClass, Object[] initParams)	Retrieve the singleton instance of a class, given the array of parameters...
Object	getStaticField(Class targetClass, String fieldName)
Object	invoke(Object target, String methodName, Object[] params)	Invoke the specified method on the specified target with the specified params...
Object	invokeStatic(Class targetClass, String methodName, Object[] params)	Invoke the specified static method with the specified params...
<T> T	newInstance(Class<T> theClass, Object[] params)	Create a new instance of a class, given the array of parameters...

Methods inherited from class java.lang.Object

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

Constructor Detail

Reflector

public Reflector()

Ensure no instances of Reflector are created...this is a utility.

Method Detail

newInstance

public <T> T newInstance(Class<T> theClass,
                         Object[] params)
                  throws ReflectorException

Create a new instance of a class, given the array of parameters... Uses constructor caching to find a constructor that matches the parameter types, either specifically (first choice) or abstractly...

Type Parameters:

T - the type

Parameters:

theClass - The class to instantiate

params - The parameters to pass to the constructor

Returns:

The instantiated object

Throws:

ReflectorException - In case anything goes wrong here...

getSingleton

public <T> T getSingleton(Class<T> theClass,
                          Object[] initParams)
                   throws ReflectorException

Retrieve the singleton instance of a class, given the array of parameters... Uses constructor caching to find a constructor that matches the parameter types, either specifically (first choice) or abstractly...

Type Parameters:

T - the type

Parameters:

theClass - The class to retrieve the singleton of

initParams - The parameters to pass to the constructor

Returns:

The singleton object

Throws:

ReflectorException - In case anything goes wrong here...

invoke

public Object invoke(Object target,
                     String methodName,
                     Object[] params)
              throws ReflectorException

Invoke the specified method on the specified target with the specified params...

Parameters:

target - The target of the invocation

methodName - The method name to invoke

params - The parameters to pass to the method invocation

Returns:

The result of the method call

Throws:

ReflectorException - In case of an error looking up or invoking the method.

getStaticField

public Object getStaticField(Class targetClass,
                             String fieldName)
                      throws ReflectorException

Throws:

ReflectorException

getField

public Object getField(Object target,
                       String fieldName)
                throws ReflectorException

Throws:

ReflectorException

getField

public Object getField(Object target,
                       String fieldName,
                       boolean breakAccessibility)
                throws ReflectorException

Throws:

ReflectorException

invokeStatic

public Object invokeStatic(Class targetClass,
                           String methodName,
                           Object[] params)
                    throws ReflectorException

Invoke the specified static method with the specified params...

Parameters:

targetClass - The target class of the invocation

methodName - The method name to invoke

params - The parameters to pass to the method invocation

Returns:

The result of the method call

Throws:

ReflectorException - In case of an error looking up or invoking the method.

getConstructor

public <T> Constructor<T> getConstructor(Class<T> targetClass,
                                         Class[] params)
                                  throws ReflectorException

Return the constructor, checking the cache first and storing in cache if not already there..

Type Parameters:

T - the type

Parameters:

targetClass - The class to get the constructor from

params - The classes of the parameters which the constructor should match.

Returns:

the Constructor object that matches.

Throws:

ReflectorException - In case we can't retrieve the proper constructor.

getObjectProperty

public Object getObjectProperty(Object target,
                                String propertyName)
                         throws ReflectorException

Throws:

ReflectorException

getMethod

public Method getMethod(Class targetClass,
                        String methodName,
                        Class[] params)
                 throws ReflectorException

Return the method, checking the cache first and storing in cache if not already there..

Parameters:

targetClass - The class to get the method from

params - The classes of the parameters which the method should match.

methodName - the method name

Returns:

the Method object that matches.

Throws:

ReflectorException - In case we can't retrieve the proper method.