/**
* Copyright (C) 2011 JTalks.org Team
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
package org.jtalks.jcommune.web.controller;
import org.apache.commons.lang.time.DateFormatUtils;
import org.jtalks.jcommune.service.exceptions.ImageFormatException;
import org.jtalks.jcommune.service.exceptions.ImageProcessException;
import org.jtalks.jcommune.service.exceptions.ImageSizeException;
import org.jtalks.jcommune.plugin.api.web.dto.json.FailJsonResponse;
import org.jtalks.jcommune.plugin.api.web.dto.json.JsonResponseReason;
import org.jtalks.jcommune.web.util.ImageControllerUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.context.MessageSource;
import org.springframework.http.HttpHeaders;
import org.springframework.http.MediaType;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.multipart.MultipartFile;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.text.DateFormat;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.HashMap;
import java.util.Locale;
import java.util.Map;
import java.util.concurrent.TimeUnit;
/**
* Base class for handling uploaded images and generating preview for them
*/
public class ImageUploadController {
/** We cannot set it to forever since avatars sometimes change, but this is a pretty rare event. */
static long AVATAR_CACHE_AGE_SEC = TimeUnit.DAYS.toSeconds(30);
private MessageSource messageSource;
static final String WRONG_FORMAT_RESOURCE_MESSAGE = "image.wrong.format";
static final String WRONG_SIZE_RESOURCE_MESSAGE = "image.wrong.size";
static final String COMMON_ERROR_RESOURCE_MESSAGE = "avatar.500.common.error";
protected static final String IF_MODIFIED_SINCE_HEADER = "If-Modified-Since";
static final String HTTP_HEADER_DATETIME_PATTERN = "E, dd MMM yyyy HH:mm:ss z";
private static final Logger LOGGER = LoggerFactory.getLogger(ImageUploadController.class);
public ImageUploadController(MessageSource messageSource) {
this.messageSource = messageSource;
}
/**
* Handles an exception that is thrown when the image has incorrect size.
*
* @param e exception
* @param locale locale, it's needed for error message localization
* @return DTO, that contains information about error, it will be converted to JSON
*/
@ExceptionHandler(value = ImageSizeException.class)
@ResponseBody
public FailJsonResponse handleImageSizeException(ImageSizeException e, Locale locale) {
Object[] parameters = new Object[]{e.getMaxSize()};
String errorMessage = messageSource.getMessage(WRONG_SIZE_RESOURCE_MESSAGE, parameters, locale);
return new FailJsonResponse(JsonResponseReason.VALIDATION, errorMessage);
}
/**
* Handles an exception that is thrown when the image has incorrect format.
*
* @param e exception
* @param locale locale, it's needed for error message localization
* @return DTO, that contains information about error, it will be converted to JSON
*/
@ExceptionHandler(value = ImageFormatException.class)
@ResponseBody
public FailJsonResponse handleImageFormatException(ImageFormatException e, Locale locale) {
Object[] validImageTypes = new Object[]{e.getValidImageTypes()};
String errorMessage = messageSource.getMessage(WRONG_FORMAT_RESOURCE_MESSAGE, validImageTypes, locale);
return new FailJsonResponse(JsonResponseReason.VALIDATION, errorMessage);
}
/**
* Handles common exception that can occur when loading an image.
*
* @param e exception
* @param locale locale, it's needed for error message localization
* @return DTO, that contains information about error, it will be converted to JSON
*/
@ExceptionHandler(value = ImageProcessException.class)
@ResponseBody
public FailJsonResponse handleImageProcessException(ImageProcessException e, Locale locale) {
String errorMessage = messageSource.getMessage(COMMON_ERROR_RESOURCE_MESSAGE, null, locale);
return new FailJsonResponse(JsonResponseReason.INTERNAL_SERVER_ERROR, errorMessage);
}
/**
* Gets service for resolving messages
*
* @return service for resolving messages
*/
public MessageSource getMessageSource() {
return messageSource;
}
/**
* Sets up avatar cache related headers.
*
* @param response - HTTP response object where set headers
* @param avatarLastModificationTime - last modification time of avatar
*/
protected void setupAvatarHeaders(HttpServletResponse response, Date avatarLastModificationTime) {
response.setHeader("Pragma", "public");
response.setDateHeader("Expires", System.currentTimeMillis() + AVATAR_CACHE_AGE_SEC * 1000);
response.setHeader("Cache-Control", "public");
response.addHeader("Cache-Control", "max-age=" + AVATAR_CACHE_AGE_SEC);
String formattedDateLastModified = DateFormatUtils.format(
avatarLastModificationTime,
HTTP_HEADER_DATETIME_PATTERN, Locale.US);
response.setHeader("Last-Modified", formattedDateLastModified);
}
/**
* Check 'If-Modified-Since' header in the request and converts it to
* {@link java.util.Date} representation
*
* @param ifModifiedSinceHeader - value of 'If-Modified-Since' header in
* string form
* @return If-Modified-Since header or Jan 1, 1970 if it is not set or
* can't be parsed
*/
public Date getIfModifiedSinceDate(String ifModifiedSinceHeader) {
Date ifModifiedSinceDate = new Date(0);
if (ifModifiedSinceHeader != null) {
try {
DateFormat dateFormat = new SimpleDateFormat(
HTTP_HEADER_DATETIME_PATTERN,
Locale.US);
ifModifiedSinceDate = dateFormat.parse(ifModifiedSinceHeader);
} catch (ParseException e) {
LOGGER.error("Failed to parse value of 'If-Modified-Since' header from string form.", e);
}
}
return ifModifiedSinceDate;
}
/**
* Gets uploaded image and generates preview to send back to the client
*
* @param file file, that contains uploaded image
* @param imageControllerUtils object for processing the image
* @return generated preview of the uploaded image
* @throws IOException
* @throws ImageProcessException
*/
protected ResponseEntity<String> createPreviewOfImage(MultipartFile file, ImageControllerUtils imageControllerUtils)
throws IOException, ImageProcessException {
HttpHeaders responseHeaders = new HttpHeaders();
responseHeaders.setContentType(MediaType.TEXT_HTML);
Map<String, String> responseContent = new HashMap<>();
return imageControllerUtils.prepareResponse(file, responseHeaders, responseContent);
}
/**
* Gets uploaded image and generates preview to send back to the client
*
* @param imageBytes content of the uploaded image
* @param response HTTP response
* @param imageControllerUtils object for processing the image
* @return generated preview of the uploaded image
* @throws ImageProcessException
*/
protected Map<String, String> createPreviewOfImage(byte[] imageBytes, HttpServletResponse response,
ImageControllerUtils imageControllerUtils)
throws ImageProcessException {
Map<String, String> responseContent = new HashMap<>();
imageControllerUtils.prepareResponse(imageBytes, response, responseContent);
return responseContent;
}
}