com.sun.jersey.core.reflection
Class ReflectionHelper

java.lang.Object
  com.sun.jersey.core.reflection.ReflectionHelper

public class ReflectionHelper
extends java.lang.Object

Utility methods for Java reflection.

Author:

[email protected]

ReflectionHelper

public ReflectionHelper()

getDeclaringClass

public static java.lang.Class getDeclaringClass(java.lang.reflect.AccessibleObject ao)

objectToString

public static java.lang.String objectToString(java.lang.Object o)

Create a string representation of an object.

Returns a string consisting of the name of the class of which the object is an instance, the at-sign character '@', and the unsigned hexadecimal representation of the hash code of the object. In other words, this method returns a string equal to the value of:

 o.getClass().getName() + '@' + Integer.toHexString(o.hashCode())
 

Parameters:

o - the object.

Returns:

the string representation of the object.

methodInstanceToString

public static java.lang.String methodInstanceToString(java.lang.Object o,
                                                      java.lang.reflect.Method m)

Create a string representation of a method and an instance whose class implements the method.

Returns a string consisting of the name of the class of which the object is an instance, the at-sign character '@', the unsigned hexadecimal representation of the hash code of the object, the character '.', the name of the method, the character '(', the list of method parameters, and the character ')'. In other words, thos method returns a string equal to the value of:

 o.getClass().getName() + '@' + Integer.toHexString(o.hashCode()) +
 '.' + m.getName() + '(' + <parameters> + ')'.
 

Parameters:

o - the object whose class implements m.

m - the method.

Returns:

the string representation of the method and instance.

classForName

public static java.lang.Class classForName(java.lang.String name)

Get the Class from the class name.

The context class loader will be utilized if accessible and non-null. Otherwise the defining class loader of this class will be utilized.

Parameters:

name - the class name.

Returns:

the Class, otherwise null if the class cannot be found.

classForName

public static java.lang.Class classForName(java.lang.String name,
                                           java.lang.ClassLoader cl)

Get the Class from the class name.

Parameters:

name - the class name.

cl - the class loader to use, if null then the defining class loader of this class will be utilized.

Returns:

the Class, otherwise null if the class cannot be found.

classForNameWithException

public static java.lang.Class classForNameWithException(java.lang.String name)
                                                 throws java.lang.ClassNotFoundException

Get the Class from the class name.

The context class loader will be utilized if accessible and non-null. Otherwise the defining class loader of this class will be utilized.

Parameters:

name - the class name.

Returns:

the Class, otherwise null if the class cannot be found.

Throws:

java.lang.ClassNotFoundException - if the class cannot be found.

classForNameWithException

public static java.lang.Class classForNameWithException(java.lang.String name,
                                                        java.lang.ClassLoader cl)
                                                 throws java.lang.ClassNotFoundException

Get the Class from the class name.

Parameters:

name - the class name.

cl - the class loader to use, if null then the defining class loader of this class will be utilized.

Returns:

the Class, otherwise null if the class cannot be found.

Throws:

java.lang.ClassNotFoundException - if the class cannot be found.

getContextClassLoader

public static java.lang.ClassLoader getContextClassLoader()

Get the context class loader.

Returns:

the context class loader, otherwise null security privilages are not set.

setAccessibleMethod

public static void setAccessibleMethod(java.lang.reflect.Method m)

Set a method to be accessible.

Parameters:

m - the method to be set as accessible

getGenericClass

public static java.lang.Class getGenericClass(java.lang.reflect.Type parameterizedType)
                                       throws java.lang.IllegalArgumentException

Get the class that is the type argument of a parameterized type.

Parameters:

parameterizedType - must be an instance of ParameterizedType and have exactly one type argument.

Returns:

the class of the actual type argument. If the type argument is a class then the class is returned. If the type argument is a generic array type and the generic component type is a class then class of the array is returned. if the type argument is a parameterized type and it's raw type is a class then that class is returned. If the parameterizedType is not an instance of ParameterizedType or contains more than one type argument null is returned.

Throws:

java.lang.IllegalArgumentException - if the single type argument is not of a class, or a generic array type, or the generic component type of the generic array type is not class, or not a parameterized type with a raw type that is not a class.

getTypeArgumentAndClass

public static ReflectionHelper.TypeClassPair getTypeArgumentAndClass(java.lang.reflect.Type parameterizedType)
                                                              throws java.lang.IllegalArgumentException

Throws:

java.lang.IllegalArgumentException

getArrayClass

public static java.lang.Class getArrayClass(java.lang.Class c)

Get Array class of component class.

Parameters:

c - the component class of the array

Returns:

the array class.

getValueOfStringMethod

public static java.lang.reflect.Method getValueOfStringMethod(java.lang.Class c)

Get the static valueOf(String ) method.

Parameters:

c - The class to obtain the method.

Returns:

the method, otherwise null if the method is not present.

getFromStringStringMethod

public static java.lang.reflect.Method getFromStringStringMethod(java.lang.Class c)

Get the static fromString(String ) method.

Parameters:

c - The class to obtain the method.

Returns:

the method, otherwise null if the method is not present.

getStringConstructor

public static java.lang.reflect.Constructor getStringConstructor(java.lang.Class c)

Get the constructor that has a single parameter of String.

Parameters:

c - The class to obtain the constructor.

Returns:

the constructor, otherwise null if the constructor is not present.

getParameterizedClassArguments

public static java.lang.Class[] getParameterizedClassArguments(ReflectionHelper.DeclaringClassInterfacePair p)

Get the parameterized class arguments for a declaring class that declares a generic interface type.

Parameters:

p - the declaring class

Returns:

the parameterized class arguments, or null if the generic interface type is not a parameterized type.

getParameterizedTypeArguments

public static java.lang.reflect.Type[] getParameterizedTypeArguments(ReflectionHelper.DeclaringClassInterfacePair p)

Get the parameterized type arguments for a declaring class that declares a generic interface type.

Parameters:

p - the declaring class

Returns:

the parameterized type arguments, or null if the generic interface type is not a parameterized type.

getClass

public static ReflectionHelper.DeclaringClassInterfacePair getClass(java.lang.Class concrete,
                                                                    java.lang.Class iface)

Find the declaring class that implements or extends an interface.

Parameters:

concrete - the concrete class than directly or indirectly implements or extends an interface class.

iface - the interface class.

Returns:

the tuple of the declaring class and the generic interface type.

resolveTypeVariable

public static ReflectionHelper.ClassTypePair resolveTypeVariable(java.lang.Class c,
                                                                 java.lang.Class dc,
                                                                 java.lang.reflect.TypeVariable tv)

Given a type variable resolve the Java class of that variable.

Parameters:

c - the concrete class from which all type variables are resolved

dc - the declaring class where the type variable was defined

tv - the type variable

Returns:

the resolved Java class and type, otherwise null if the type variable could not be resolved

findMethodOnClass

public static java.lang.reflect.Method findMethodOnClass(java.lang.Class c,
                                                         java.lang.reflect.Method m)

Find a method on a class given an existing method.

If there exists a public method on the class that has the same name and parameters as the existing method then that public method is returned.

Otherwise, if there exists a public method on the class that has the same name and the same number of parameters as the existing method, and each generic parameter type, in order, of the public method is equal to the generic parameter type, in the same order, of the existing method or is an instance of TypeVariable then that public method is returned.

Parameters:

c - the class to search for a public method

m - the method to find

Returns:

the found public method.