The first argument is the object instance on which this particular method is to be invoked. Typically, this would only be necessary if it is not possible to cast an instance of the class to the desired type in non-reflective code. See Also: Constructor.Reflection provides a means for invoking methods on a class. NoSuchMethodException - Thrown by findCompatibleConstructor(Class, Set, Class.). InstantiationException - Thrown by Constructor.newInstance(Object.). InvocationTargetException - Thrown by Constructor.newInstance(Object.).
Throws: IllegalAccessException - Thrown by Constructor.newInstance(Object.). Returns: The instantiated object of class datatype.
parameterSignature - The typelist used to find correct constructor. Parameters: datatype - The class to find the constructor for. passing a specific type of List into a generic type) Type Parameters: T - Used to parameterize the returned object so that the caller doesn't need to cast. Can alsoīe used to force up/down casting (ie. Avoids dynamically trying to find correct parameter type list. Locates and invokes a Constructor, using a customized typelist. invokeCompatibleConstructor static T invokeCompatibleConstructor( Class datatype,.InvocationTargetException - Thrown by Method.invoke(Object, Object.). IllegalAccessException - Thrown by Method.invoke(Object, Object.). IllegalArgumentException - Thrown by Method.invoke(Object, Object.). Throws: NoSuchMethodException - Thrown by findCompatibleMethod(Class, String, Set, Class.). Returns: The return value of the invoke method, if successful. identifier - The name of the method to locate. datatype - The class to find the method on. Parameters: context - The object to call the method from (can be null). If this fails as well, this method will try to autoconvert the types of the argumentsĪnd find a matching signature that way. Where all interfaces are searched for the method as well. If not cached before and if a simple search (autoboxing and supertype casts) fails a more complex search is done First of all a Method cache is being maintained to quicklyįetch heavily used methods. Locates a method on an Object using serveral searchmodes for optimization. nvert(args,Ī reverse lookup is also possible: given an ordered list of possible types, is a given Method compatible?īecause this lookup is potentially very expensive, a cache is present to store lookup results. Ways to do this: use invokeCompatibleMethod(Object, Class, String, Object.) instead or perform the conversion yourself using nvert(Object, Class, boolean) prior to invoking the method. Method, but you won't be able to invoke it if it was found using a less strict lookup than one with a simple exact match. The Pear type and finally by attempting a common conversion from String to char.
In the above example, the method foo will be found by finding all methods named "Foo" on the interfaces implemented by supertype A,Īnd then foo's method signature will be matched using autoboxing on the double type, a cast to the Fruit supertype for Observe the following (trivial) example: interface Foo When this fails, it generates a list of datatype arrays (signatures) with all possible versions of any type in the original list possible, and This expanded version tries a simple call first (exact match, which is provided natively by the Java) and It tries to find a constructor of a given datatype, with a given argumentĭatatypelist, where types do not have to match formal types (auto-boxing, supertypes, implemented interfaces and type conversions are allowed as Using a combination of LookupMode strategies. This reflection tool is designed to perform advanced method or constructor lookups,
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