/*
* Copyright 2016 Nabarun Mondal
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*/
package com.noga.njexl.lang.introspection;
/**
* Interface used for regular method invocation.
* Ex.
* <code>
* ${foo.bar()}
* </code>
*
* @since 1.0
*/
public interface JexlMethod {
/**
* Invocation method, called when the method invocation should be performed
* and a value returned.
* @param obj the object
* @param params method parameters.
* @return the result
* @throws Exception on any error.
*/
Object invoke(Object obj, Object[] params) throws Exception;
/**
* Attempts to reuse this JexlMethod, checking that it is compatible with
* the actual set of arguments.
* Related to isCacheable since this method is often used with cached JexlMethod instances.
* @param obj the object to invoke the method upon
* @param name the method name
* @param params the method arguments
* @return the result of the method invocation that should be checked by tryFailed to determine if it succeeded
* or failed.
*/
Object tryInvoke(String name, Object obj, Object[] params);
/**
* Checks whether a tryInvoke failed or not.
* @param rval the value returned by tryInvoke
* @return true if tryInvoke failed, false otherwise
*/
boolean tryFailed(Object rval);
/**
* Specifies if this JexlMethod is cacheable and able to be reused for this
* class of object it was returned for.
*
* @return true if can be reused for this class, false if not
*/
boolean isCacheable();
/**
* returns the return type of the method invoked.
* @return return type
*/
Class<?> getReturnType();
}