import org.springframework.lang.UsesJava8; //导入依赖的package包/类
@UsesJava8
private void setCreationTimeIfPossible(JarEntry source, JarEntry target) {
	try {
		if (source.getCreationTime() != null) {
			target.setCreationTime(source.getCreationTime());
		}
	}
	catch (NoSuchMethodError ex) {
		// Not running on Java 8. Continue.
	}
}
 

import org.springframework.lang.UsesJava8; //导入依赖的package包/类
@UsesJava8
private void setLastAccessTimeIfPossible(JarEntry source, JarEntry target) {
	try {
		if (source.getLastAccessTime() != null) {
			target.setLastAccessTime(source.getLastAccessTime());
		}
	}
	catch (NoSuchMethodError ex) {
		// Not running on Java 8. Continue.
	}
}
 

import org.springframework.lang.UsesJava8; //导入依赖的package包/类
@UsesJava8
private void setLastModifiedTimeIfPossible(JarEntry source, JarEntry target) {
	try {
		if (source.getLastModifiedTime() != null) {
			target.setLastModifiedTime(source.getLastModifiedTime());
		}
	}
	catch (NoSuchMethodError ex) {
		// Not running on Java 8. Continue.
	}
}
 

import org.springframework.lang.UsesJava8; //导入依赖的package包/类
@Override
@UsesJava8
public Object resolveArgument(MethodParameter parameter, ModelAndViewContainer mavContainer,
		NativeWebRequest request, WebDataBinderFactory binderFactory) throws Exception {

	HttpServletRequest servletRequest = request.getNativeRequest(HttpServletRequest.class);
	assertIsMultipartRequest(servletRequest);

	MultipartHttpServletRequest multipartRequest =
			WebUtils.getNativeRequest(servletRequest, MultipartHttpServletRequest.class);

	Class<?> paramType = parameter.getParameterType();
	boolean optional = paramType.getName().equals("java.util.Optional");
	if (optional) {
		parameter.increaseNestingLevel();
		paramType = parameter.getNestedParameterType();
	}

	String partName = getPartName(parameter);
	Object arg;

	if (MultipartFile.class == paramType) {
		Assert.notNull(multipartRequest, "Expected MultipartHttpServletRequest: is a MultipartResolver configured?");
		arg = multipartRequest.getFile(partName);
	}
	else if (isMultipartFileCollection(parameter)) {
		Assert.notNull(multipartRequest, "Expected MultipartHttpServletRequest: is a MultipartResolver configured?");
		arg = multipartRequest.getFiles(partName);
	}
	else if (isMultipartFileArray(parameter)) {
		Assert.notNull(multipartRequest, "Expected MultipartHttpServletRequest: is a MultipartResolver configured?");
		List<MultipartFile> files = multipartRequest.getFiles(partName);
		arg = files.toArray(new MultipartFile[files.size()]);
	}
	else if ("javax.servlet.http.Part".equals(paramType.getName())) {
		assertIsMultipartRequest(servletRequest);
		arg = servletRequest.getPart(partName);
	}
	else if (isPartCollection(parameter)) {
		assertIsMultipartRequest(servletRequest);
		arg = new ArrayList<Object>(servletRequest.getParts());
	}
	else if (isPartArray(parameter)) {
		assertIsMultipartRequest(servletRequest);
		arg = RequestPartResolver.resolvePart(servletRequest);
	}
	else {
		try {
			HttpInputMessage inputMessage = new RequestPartServletServerHttpRequest(servletRequest, partName);
			arg = readWithMessageConverters(inputMessage, parameter, parameter.getNestedGenericParameterType());
			WebDataBinder binder = binderFactory.createBinder(request, arg, partName);
			if (arg != null) {
				validateIfApplicable(binder, parameter);
				if (binder.getBindingResult().hasErrors() && isBindExceptionRequired(binder, parameter)) {
					throw new MethodArgumentNotValidException(parameter, binder.getBindingResult());
				}
			}
			mavContainer.addAttribute(BindingResult.MODEL_KEY_PREFIX + partName, binder.getBindingResult());
		}
		catch (MissingServletRequestPartException ex) {
			// handled below
			arg = null;
		}
	}

	RequestPart requestPart = parameter.getParameterAnnotation(RequestPart.class);
	boolean isRequired = ((requestPart == null || requestPart.required()) && !optional);

	if (arg == null && isRequired) {
		throw new MissingServletRequestPartException(partName);
	}
	if (optional) {
		arg = Optional.ofNullable(arg);
	}

	return arg;
}