Example usage for org.springframework.core ResolvableType resolve

Introduction

In this page you can find the example usage for org.springframework.core ResolvableType resolve.

Prototype

public Class<?> resolve(Class<?> fallback) 

Source Link

Document

Resolve this type to a java.lang.Class , returning the specified fallback if the type cannot be resolved.

Usage

From source file:org.springframework.web.servlet.mvc.method.annotation.ReactiveTypeHandler.java

/**
 * Process the given reactive return value and decide whether to adapt it
 * to a {@link ResponseBodyEmitter} or a {@link DeferredResult}.
 * @return an emitter for streaming or {@code null} if handled internally
 * with a {@link DeferredResult}./*from w ww .  j a v  a  2s  .  c om*/
 */
@Nullable
public ResponseBodyEmitter handleValue(Object returnValue, MethodParameter returnType,
        ModelAndViewContainer mav, NativeWebRequest request) throws Exception {

    Assert.notNull(returnValue, "Expected return value");
    ReactiveAdapter adapter = this.reactiveRegistry.getAdapter(returnValue.getClass());
    Assert.state(adapter != null, "Unexpected return value: " + returnValue);

    ResolvableType elementType = ResolvableType.forMethodParameter(returnType).getGeneric(0);
    Class<?> elementClass = elementType.resolve(Object.class);

    Collection<MediaType> mediaTypes = getMediaTypes(request);
    Optional<MediaType> mediaType = mediaTypes.stream().filter(MimeType::isConcrete).findFirst();

    if (adapter.isMultiValue()) {
        if (mediaTypes.stream().anyMatch(MediaType.TEXT_EVENT_STREAM::includes)
                || ServerSentEvent.class.isAssignableFrom(elementClass)) {
            SseEmitter emitter = new SseEmitter(STREAMING_TIMEOUT_VALUE);
            new SseEmitterSubscriber(emitter, this.taskExecutor).connect(adapter, returnValue);
            return emitter;
        }
        if (CharSequence.class.isAssignableFrom(elementClass)) {
            ResponseBodyEmitter emitter = getEmitter(mediaType.orElse(MediaType.TEXT_PLAIN));
            new TextEmitterSubscriber(emitter, this.taskExecutor).connect(adapter, returnValue);
            return emitter;
        }
        if (mediaTypes.stream().anyMatch(MediaType.APPLICATION_STREAM_JSON::includes)) {
            ResponseBodyEmitter emitter = getEmitter(MediaType.APPLICATION_STREAM_JSON);
            new JsonEmitterSubscriber(emitter, this.taskExecutor).connect(adapter, returnValue);
            return emitter;
        }
    }

    // Not streaming...
    DeferredResult<Object> result = new DeferredResult<>();
    new DeferredResultSubscriber(result, adapter, elementType).connect(adapter, returnValue);
    WebAsyncUtils.getAsyncManager(request).startDeferredResultProcessing(result, mav);

    return null;
}

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