public class ConstructorUtils extends Object
Utility reflection methods focussed on constructors, modelled after MethodUtils.
There is an issue when invoking public constructors contained in a default access superclass.
Reflection locates these constructors fine and correctly assigns them as public.
However, an IllegalAccessException is thrown if the constructors is invoked.
ConstructorUtils contains a workaround for this situation.
It will attempt to call setAccessible on this constructor.
If this call succeeds, then the method can be invoked as normal.
This call will only succeed when the application has sufficient security privilages.
If this call fails then a warning will be logged and the method may fail.
| Constructor and Description |
|---|
ConstructorUtils() |
| Modifier and Type | Method and Description |
|---|---|
static <T> Constructor<T> |
getAccessibleConstructor(Class<T> klass,
Class<?> parameterType)
Returns a constructor with single argument.
|
static <T> Constructor<T> |
getAccessibleConstructor(Class<T> klass,
Class<?>[] parameterTypes)
Returns a constructor given a class and signature.
|
static <T> Constructor<T> |
getAccessibleConstructor(Constructor<T> ctor)
Returns accessible version of the given constructor.
|
static <T> T |
invokeConstructor(Class<T> klass,
Object arg)
Convenience method returning new instance of
klazz using a single argument constructor. |
static <T> T |
invokeConstructor(Class<T> klass,
Object[] args)
Returns new instance of
klazz created using the actual arguments args. |
static <T> T |
invokeConstructor(Class<T> klass,
Object[] args,
Class<?>[] parameterTypes)
Returns new instance of
klazz created using constructor
with signature parameterTypes and actual arguments args. |
static <T> T |
invokeExactConstructor(Class<T> klass,
Object arg)
Convenience method returning new instance of
klazz using a single argument constructor. |
static <T> T |
invokeExactConstructor(Class<T> klass,
Object[] args)
Returns new instance of
klazz created using the actual arguments args. |
static <T> T |
invokeExactConstructor(Class<T> klass,
Object[] args,
Class<?>[] parameterTypes)
Returns new instance of
klazz created using constructor
with signature parameterTypes and actual arguments
args. |
public ConstructorUtils()
public static <T> T invokeConstructor(Class<T> klass, Object arg) throws NoSuchMethodException, IllegalAccessException, InvocationTargetException, InstantiationException
Convenience method returning new instance of klazz using a single argument constructor.
The formal parameter type is inferred from the actual values of arg.
See invokeExactConstructor(Class, Object[], Class[]) for more details.
The signatures should be assignment compatible.
T - the type of the object to be constructedklass - the class to be constructed.arg - the actual argument. May be null (this will result in calling the default constructor).klazzNoSuchMethodException - If the constructor cannot be foundIllegalAccessException - If an error occurs accessing the constructorInvocationTargetException - If an error occurs invoking the constructorInstantiationException - If an error occurs instantiating the classinvokeConstructor(java.lang.Class, java.lang.Object[], java.lang.Class[])public static <T> T invokeConstructor(Class<T> klass, Object[] args) throws NoSuchMethodException, IllegalAccessException, InvocationTargetException, InstantiationException
Returns new instance of klazz created using the actual arguments args.
The formal parameter types are inferred from the actual values of args.
See invokeExactConstructor(Class, Object[], Class[]) for more details.
The signatures should be assignment compatible.
T - the type of the object to be constructedklass - the class to be constructed.args - actual argument array. May be null (this will result in calling the default constructor).klazzNoSuchMethodException - If the constructor cannot be foundIllegalAccessException - If an error occurs accessing the constructorInvocationTargetException - If an error occurs invoking the constructorInstantiationException - If an error occurs instantiating the classinvokeConstructor(java.lang.Class, java.lang.Object[], java.lang.Class[])public static <T> T invokeConstructor(Class<T> klass, Object[] args, Class<?>[] parameterTypes) throws NoSuchMethodException, IllegalAccessException, InvocationTargetException, InstantiationException
Returns new instance of klazz created using constructor
with signature parameterTypes and actual arguments args.
The signatures should be assignment compatible.
T - the type of the object to be constructedklass - the class to be constructed.args - actual argument array. May be null (this will result in calling the default constructor).parameterTypes - parameter types arrayklazzNoSuchMethodException - if matching constructor cannot be foundIllegalAccessException - thrown on the constructor's invocationInvocationTargetException - thrown on the constructor's invocationInstantiationException - thrown on the constructor's invocationConstructor.newInstance(java.lang.Object...)public static <T> T invokeExactConstructor(Class<T> klass, Object arg) throws NoSuchMethodException, IllegalAccessException, InvocationTargetException, InstantiationException
Convenience method returning new instance of klazz using a single argument constructor.
The formal parameter type is inferred from the actual values of arg.
See invokeExactConstructor(Class, Object[], Class[]) for more details.
The signatures should match exactly.
T - the type of the object to be constructedklass - the class to be constructed.arg - the actual argument. May be null (this will result in calling the default constructor).klazzNoSuchMethodException - If the constructor cannot be foundIllegalAccessException - If an error occurs accessing the constructorInvocationTargetException - If an error occurs invoking the constructorInstantiationException - If an error occurs instantiating the classinvokeExactConstructor(java.lang.Class, java.lang.Object[], java.lang.Class[])public static <T> T invokeExactConstructor(Class<T> klass, Object[] args) throws NoSuchMethodException, IllegalAccessException, InvocationTargetException, InstantiationException
Returns new instance of klazz created using the actual arguments args.
The formal parameter types are inferred from the actual values of args.
See invokeExactConstructor(Class, Object[], Class[]) for more details.
The signatures should match exactly.
T - the type of the object to be constructedklass - the class to be constructed.args - actual argument array. May be null (this will result in calling the default constructor).klazzNoSuchMethodException - If the constructor cannot be foundIllegalAccessException - If an error occurs accessing the constructorInvocationTargetException - If an error occurs invoking the constructorInstantiationException - If an error occurs instantiating the classinvokeExactConstructor(java.lang.Class, java.lang.Object[], java.lang.Class[])public static <T> T invokeExactConstructor(Class<T> klass, Object[] args, Class<?>[] parameterTypes) throws NoSuchMethodException, IllegalAccessException, InvocationTargetException, InstantiationException
Returns new instance of klazz created using constructor
with signature parameterTypes and actual arguments
args.
The signatures should match exactly.
T - the type of the object to be constructedklass - the class to be constructed.args - actual argument array. May be null (this will result in calling the default constructor).parameterTypes - parameter types arrayklazzNoSuchMethodException - if matching constructor cannot be foundIllegalAccessException - thrown on the constructor's invocationInvocationTargetException - thrown on the constructor's invocationInstantiationException - thrown on the constructor's invocationConstructor.newInstance(java.lang.Object...)public static <T> Constructor<T> getAccessibleConstructor(Class<T> klass, Class<?> parameterType)
T - the type of the constructorklass - the class to be constructedparameterType - The constructor parameter typeClass.getConstructor(java.lang.Class<?>...),
getAccessibleConstructor(java.lang.reflect.Constructor)public static <T> Constructor<T> getAccessibleConstructor(Class<T> klass, Class<?>[] parameterTypes)
T - the type to be constructedklass - the class to be constructedparameterTypes - the parameter arrayClass.getConstructor(java.lang.Class<?>...),
getAccessibleConstructor(java.lang.reflect.Constructor)public static <T> Constructor<T> getAccessibleConstructor(Constructor<T> ctor)
T - the type of the constructorctor - prototype constructor object.null if accessible constructor can not be found.SecurityManagerCopyright © 2000–2019 The Apache Software Foundation. All rights reserved.