Java tutorial
/* * Copyright 2002-2015 the original author or authors. * * 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 * * https://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 org.springframework.context; import org.springframework.core.ResolvableType; import org.springframework.core.ResolvableTypeProvider; import org.springframework.util.Assert; /** * An {@link ApplicationEvent} that carries an arbitrary payload. * * <p>Mainly intended for internal use within the framework. * * @author Stephane Nicoll * @since 4.2 * @param <T> the payload type of the event */ @SuppressWarnings("serial") public class PayloadApplicationEvent<T> extends ApplicationEvent implements ResolvableTypeProvider { private final T payload; /** * Create a new PayloadApplicationEvent. * @param source the object on which the event initially occurred (never {@code null}) * @param payload the payload object (never {@code null}) */ public PayloadApplicationEvent(Object source, T payload) { super(source); Assert.notNull(payload, "Payload must not be null"); this.payload = payload; } @Override public ResolvableType getResolvableType() { return ResolvableType.forClassWithGenerics(getClass(), ResolvableType.forInstance(getPayload())); } /** * Return the payload of the event. */ public T getPayload() { return this.payload; } }