/*
* Copyright 2002-2018 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.web.servlet.mvc.method.annotation;
import java.io.IOException;
import java.io.InputStream;
import java.io.PushbackInputStream;
import java.lang.annotation.Annotation;
import java.lang.reflect.Type;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.EnumSet;
import java.util.LinkedHashSet;
import java.util.List;
import java.util.Optional;
import java.util.Set;
import javax.servlet.http.HttpServletRequest;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.core.MethodParameter;
import org.springframework.core.ResolvableType;
import org.springframework.core.annotation.AnnotationUtils;
import org.springframework.core.log.LogFormatUtils;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpInputMessage;
import org.springframework.http.HttpMethod;
import org.springframework.http.HttpRequest;
import org.springframework.http.InvalidMediaTypeException;
import org.springframework.http.MediaType;
import org.springframework.http.converter.GenericHttpMessageConverter;
import org.springframework.http.converter.HttpMessageConverter;
import org.springframework.http.converter.HttpMessageNotReadableException;
import org.springframework.http.server.ServletServerHttpRequest;
import org.springframework.lang.Nullable;
import org.springframework.util.Assert;
import org.springframework.util.StreamUtils;
import org.springframework.validation.Errors;
import org.springframework.validation.annotation.Validated;
import org.springframework.web.HttpMediaTypeNotSupportedException;
import org.springframework.web.bind.WebDataBinder;
import org.springframework.web.context.request.NativeWebRequest;
import org.springframework.web.method.support.HandlerMethodArgumentResolver;
/**
* A base class for resolving method argument values by reading from the body of
* a request with {@link HttpMessageConverter HttpMessageConverters}.
*
* @author Arjen Poutsma
* @author Rossen Stoyanchev
* @author Juergen Hoeller
* @since 3.1
*/
public abstract class AbstractMessageConverterMethodArgumentResolver implements HandlerMethodArgumentResolver {
private static final Set<HttpMethod> SUPPORTED_METHODS =
EnumSet.of(HttpMethod.POST, HttpMethod.PUT, HttpMethod.PATCH);
private static final Object NO_VALUE = new Object();
protected final Log logger = LogFactory.getLog(getClass());
protected final List<HttpMessageConverter<?>> messageConverters;
protected final List<MediaType> allSupportedMediaTypes;
private final RequestResponseBodyAdviceChain advice;
/**
* Basic constructor with converters only.
*/
public AbstractMessageConverterMethodArgumentResolver(List<HttpMessageConverter<?>> converters) {
this(converters, null);
}
/**
* Constructor with converters and {@code Request~} and {@code ResponseBodyAdvice}.
* @since 4.2
*/
public AbstractMessageConverterMethodArgumentResolver(List<HttpMessageConverter<?>> converters,
@Nullable List<Object> requestResponseBodyAdvice) {
Assert.notEmpty(converters, "'messageConverters' must not be empty");
this.messageConverters = converters;
this.allSupportedMediaTypes = getAllSupportedMediaTypes(converters);
this.advice = new RequestResponseBodyAdviceChain(requestResponseBodyAdvice);
}
/**
* Return the media types supported by all provided message converters sorted
* by specificity via {@link MediaType#sortBySpecificity(List)}.
*/
private static List<MediaType> getAllSupportedMediaTypes(List<HttpMessageConverter<?>> messageConverters) {
Set<MediaType> allSupportedMediaTypes = new LinkedHashSet<>();
for (HttpMessageConverter<?> messageConverter : messageConverters) {
allSupportedMediaTypes.addAll(messageConverter.getSupportedMediaTypes());
}
List<MediaType> result = new ArrayList<>(allSupportedMediaTypes);
MediaType.sortBySpecificity(result);
return Collections.unmodifiableList(result);
}
/**
* Return the configured {@link RequestBodyAdvice} and
* {@link RequestBodyAdvice} where each instance may be wrapped as a
* {@link org.springframework.web.method.ControllerAdviceBean ControllerAdviceBean}.
*/
RequestResponseBodyAdviceChain getAdvice() {
return this.advice;
}
/**
* Create the method argument value of the expected parameter type by
* reading from the given request.
* @param <T> the expected type of the argument value to be created
* @param webRequest the current request
* @param parameter the method parameter descriptor (may be {@code null})
* @param paramType the type of the argument value to be created
* @return the created method argument value
* @throws IOException if the reading from the request fails
* @throws HttpMediaTypeNotSupportedException if no suitable message converter is found
*/
@Nullable
protected <T> Object readWithMessageConverters(NativeWebRequest webRequest, MethodParameter parameter,
Type paramType) throws IOException, HttpMediaTypeNotSupportedException, HttpMessageNotReadableException {
HttpInputMessage inputMessage = createInputMessage(webRequest);
return readWithMessageConverters(inputMessage, parameter, paramType);
}
/**
* Create the method argument value of the expected parameter type by reading
* from the given HttpInputMessage.
* @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 (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, inputMessage);
}
if (body == NO_VALUE) {
if (httpMethod == null || !SUPPORTED_METHODS.contains(httpMethod) ||
(noContentType && !message.hasBody())) {
return null;
}
throw new HttpMediaTypeNotSupportedException(contentType, this.allSupportedMediaTypes);
}
MediaType selectedContentType = contentType;
Object theBody = body;
LogFormatUtils.traceDebug(logger, traceOn -> {
String formatted = LogFormatUtils.formatValue(theBody, !traceOn);
return "Read \"" + selectedContentType + "\" to [" + formatted + "]";
});
return body;
}
/**
* Create a new {@link HttpInputMessage} from the given {@link NativeWebRequest}.
* @param webRequest the web request to create an input message from
* @return the input message
*/
protected ServletServerHttpRequest createInputMessage(NativeWebRequest webRequest) {
HttpServletRequest servletRequest = webRequest.getNativeRequest(HttpServletRequest.class);
Assert.state(servletRequest != null, "No HttpServletRequest");
return new ServletServerHttpRequest(servletRequest);
}
/**
* Validate the binding target if applicable.
* <p>The default implementation checks for {@code @javax.validation.Valid},
* Spring's {@link org.springframework.validation.annotation.Validated},
* and custom annotations whose name starts with "Valid".
* @param binder the DataBinder to be used
* @param parameter the method parameter descriptor
* @since 4.1.5
* @see #isBindExceptionRequired
*/
protected void validateIfApplicable(WebDataBinder binder, MethodParameter parameter) {
Annotation[] annotations = parameter.getParameterAnnotations();
for (Annotation ann : annotations) {
Validated validatedAnn = AnnotationUtils.getAnnotation(ann, Validated.class);
if (validatedAnn != null || ann.annotationType().getSimpleName().startsWith("Valid")) {
Object hints = (validatedAnn != null ? validatedAnn.value() : AnnotationUtils.getValue(ann));
Object[] validationHints = (hints instanceof Object[] ? (Object[]) hints : new Object[] {hints});
binder.validate(validationHints);
break;
}
}
}
/**
* Whether to raise a fatal bind exception on validation errors.
* @param binder the data binder used to perform data binding
* @param parameter the method parameter descriptor
* @return {@code true} if the next method argument is not of type {@link Errors}
* @since 4.1.5
*/
protected boolean isBindExceptionRequired(WebDataBinder binder, MethodParameter parameter) {
int i = parameter.getParameterIndex();
Class<?>[] paramTypes = parameter.getExecutable().getParameterTypes();
boolean hasBindingResult = (paramTypes.length > (i + 1) && Errors.class.isAssignableFrom(paramTypes[i + 1]));
return !hasBindingResult;
}
/**
* Adapt the given argument against the method parameter, if necessary.
* @param arg the resolved argument
* @param parameter the method parameter descriptor
* @return the adapted argument, or the original resolved argument as-is
* @since 4.3.5
*/
@Nullable
protected Object adaptArgumentIfNecessary(@Nullable Object arg, MethodParameter parameter) {
if (parameter.getParameterType() == Optional.class) {
if (arg == null || (arg instanceof Collection && ((Collection<?>) arg).isEmpty()) ||
(arg instanceof Object[] && ((Object[]) arg).length == 0)) {
return Optional.empty();
}
else {
return Optional.of(arg);
}
}
return arg;
}
private static class EmptyBodyCheckingHttpInputMessage implements HttpInputMessage {
private final HttpHeaders headers;
@Nullable
private final InputStream body;
public EmptyBodyCheckingHttpInputMessage(HttpInputMessage inputMessage) throws IOException {
this.headers = inputMessage.getHeaders();
InputStream inputStream = inputMessage.getBody();
if (inputStream.markSupported()) {
inputStream.mark(1);
this.body = (inputStream.read() != -1 ? inputStream : null);
inputStream.reset();
}
else {
PushbackInputStream pushbackInputStream = new PushbackInputStream(inputStream);
int b = pushbackInputStream.read();
if (b == -1) {
this.body = null;
}
else {
this.body = pushbackInputStream;
pushbackInputStream.unread(b);
}
}
}
@Override
public HttpHeaders getHeaders() {
return this.headers;
}
@Override
public InputStream getBody() {
return (this.body != null ? this.body : StreamUtils.emptyInput());
}
public boolean hasBody() {
return (this.body != null);
}
}
}
