Example usage for org.springframework.http.converter GenericHttpMessageConverter canRead

Introduction

In this page you can find the example usage for org.springframework.http.converter GenericHttpMessageConverter canRead.

Prototype

boolean canRead(Type type, @Nullable Class<?> contextClass, @Nullable MediaType mediaType);

Source Link

Document

Indicates whether the given type can be read by this converter.

Usage

From source file:org.springframework.web.client.HttpMessageConverterExtractor.java

@Override
@SuppressWarnings({ "unchecked", "rawtypes", "resource" })
public T extractData(ClientHttpResponse response) throws IOException {
    MessageBodyClientHttpResponseWrapper responseWrapper = new MessageBodyClientHttpResponseWrapper(response);
    if (!responseWrapper.hasMessageBody() || responseWrapper.hasEmptyMessageBody()) {
        return null;
    }//from  w  w  w.ja  va  2s  . co m
    MediaType contentType = getContentType(responseWrapper);

    try {
        for (HttpMessageConverter<?> messageConverter : this.messageConverters) {
            if (messageConverter instanceof GenericHttpMessageConverter) {
                GenericHttpMessageConverter<?> genericMessageConverter = (GenericHttpMessageConverter<?>) messageConverter;
                if (genericMessageConverter.canRead(this.responseType, null, contentType)) {
                    if (logger.isDebugEnabled()) {
                        logger.debug("Reading [" + this.responseType + "] as \"" + contentType + "\" using ["
                                + messageConverter + "]");
                    }
                    return (T) genericMessageConverter.read(this.responseType, null, responseWrapper);
                }
            }
            if (this.responseClass != null) {
                if (messageConverter.canRead(this.responseClass, contentType)) {
                    if (logger.isDebugEnabled()) {
                        logger.debug("Reading [" + this.responseClass.getName() + "] as \"" + contentType
                                + "\" using [" + messageConverter + "]");
                    }
                    return (T) messageConverter.read((Class) this.responseClass, responseWrapper);
                }
            }
        }
    } catch (IOException | HttpMessageNotReadableException ex) {
        throw new RestClientException("Error while extracting response for type [" + this.responseType
                + "] and content type [" + contentType + "]", ex);
    }

    throw new RestClientException("Could not extract response: no suitable HttpMessageConverter found "
            + "for response type [" + this.responseType + "] and content type [" + contentType + "]");
}

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

/**
 * Create the method argument value of the expected parameter type by reading
 * from the given HttpInputMessage./*from w  w w.j a va2  s . com*/
 * @param <T> the expected type of the argument value to be created
 * @param inputMessage the HTTP input message representing the current request
 * @param parameter the method parameter descriptor
 * @param targetType the target type, not necessarily the same as the method
 * parameter type, e.g. for {@code HttpEntity<String>}.
 * @return the created method argument value
 * @throws IOException if the reading from the request fails
 * @throws HttpMediaTypeNotSupportedException if no suitable message converter is found
 */
@SuppressWarnings("unchecked")
@Nullable
protected <T> Object readWithMessageConverters(HttpInputMessage inputMessage, MethodParameter parameter,
        Type targetType)
        throws IOException, HttpMediaTypeNotSupportedException, HttpMessageNotReadableException {

    MediaType contentType;
    boolean noContentType = false;
    try {
        contentType = inputMessage.getHeaders().getContentType();
    } catch (InvalidMediaTypeException ex) {
        throw new HttpMediaTypeNotSupportedException(ex.getMessage());
    }
    if (contentType == null) {
        noContentType = true;
        contentType = MediaType.APPLICATION_OCTET_STREAM;
    }

    Class<?> contextClass = parameter.getContainingClass();
    Class<T> targetClass = (targetType instanceof Class ? (Class<T>) targetType : null);
    if (targetClass == null) {
        ResolvableType resolvableType = ResolvableType.forMethodParameter(parameter);
        targetClass = (Class<T>) resolvableType.resolve();
    }

    HttpMethod httpMethod = (inputMessage instanceof HttpRequest ? ((HttpRequest) inputMessage).getMethod()
            : null);
    Object body = NO_VALUE;

    EmptyBodyCheckingHttpInputMessage message;
    try {
        message = new EmptyBodyCheckingHttpInputMessage(inputMessage);

        for (HttpMessageConverter<?> converter : this.messageConverters) {
            Class<HttpMessageConverter<?>> converterType = (Class<HttpMessageConverter<?>>) converter
                    .getClass();
            GenericHttpMessageConverter<?> genericConverter = (converter instanceof GenericHttpMessageConverter
                    ? (GenericHttpMessageConverter<?>) converter
                    : null);
            if (genericConverter != null ? genericConverter.canRead(targetType, contextClass, contentType)
                    : (targetClass != null && converter.canRead(targetClass, contentType))) {
                if (logger.isDebugEnabled()) {
                    logger.debug(
                            "Read [" + targetType + "] as \"" + contentType + "\" with [" + converter + "]");
                }
                if (message.hasBody()) {
                    HttpInputMessage msgToUse = getAdvice().beforeBodyRead(message, parameter, targetType,
                            converterType);
                    body = (genericConverter != null ? genericConverter.read(targetType, contextClass, msgToUse)
                            : ((HttpMessageConverter<T>) converter).read(targetClass, msgToUse));
                    body = getAdvice().afterBodyRead(body, msgToUse, parameter, targetType, converterType);
                } else {
                    body = getAdvice().handleEmptyBody(null, message, parameter, targetType, converterType);
                }
                break;
            }
        }
    } catch (IOException ex) {
        throw new HttpMessageNotReadableException("I/O error while reading input message", ex);
    }

    if (body == NO_VALUE) {
        if (httpMethod == null || !SUPPORTED_METHODS.contains(httpMethod)
                || (noContentType && !message.hasBody())) {
            return null;
        }
        throw new HttpMediaTypeNotSupportedException(contentType, this.allSupportedMediaTypes);
    }

    return body;
}

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