org.springframework.messaging.handler.invocation.ReactiveReturnValueHandler.java Source code

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Here is the source code for org.springframework.messaging.handler.invocation.ReactiveReturnValueHandler.java

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/*
 * Copyright 2002-2019 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.messaging.handler.invocation;

import reactor.core.publisher.Mono;

import org.springframework.core.MethodParameter;
import org.springframework.core.ReactiveAdapter;
import org.springframework.core.ReactiveAdapterRegistry;
import org.springframework.util.concurrent.ListenableFuture;
import org.springframework.util.concurrent.MonoToListenableFutureAdapter;

/**
 * Support for single-value reactive types (like {@code Mono} or {@code Single})
 * as a return value type.
 *
 * @author Sebastien Deleuze
 * @since 5.1
 */
public class ReactiveReturnValueHandler extends AbstractAsyncReturnValueHandler {

    private final ReactiveAdapterRegistry adapterRegistry;

    public ReactiveReturnValueHandler() {
        this(ReactiveAdapterRegistry.getSharedInstance());
    }

    public ReactiveReturnValueHandler(ReactiveAdapterRegistry adapterRegistry) {
        this.adapterRegistry = adapterRegistry;
    }

    @Override
    public boolean supportsReturnType(MethodParameter returnType) {
        return (this.adapterRegistry.getAdapter(returnType.getParameterType()) != null);
    }

    @Override
    public boolean isAsyncReturnValue(Object returnValue, MethodParameter returnType) {
        ReactiveAdapter adapter = this.adapterRegistry.getAdapter(returnType.getParameterType(), returnValue);
        return (adapter != null && !adapter.isMultiValue() && !adapter.isNoValue());
    }

    @Override
    public ListenableFuture<?> toListenableFuture(Object returnValue, MethodParameter returnType) {
        ReactiveAdapter adapter = this.adapterRegistry.getAdapter(returnType.getParameterType(), returnValue);
        if (adapter != null) {
            return new MonoToListenableFutureAdapter<>(Mono.from(adapter.toPublisher(returnValue)));
        }
        return null;
    }

}