Java tutorial
package org.literacyapp.web.content.multimedia.audio; import java.io.IOException; import java.net.URLEncoder; import java.util.Calendar; import javax.servlet.ServletException; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpSession; import org.apache.commons.lang.StringUtils; import org.apache.log4j.Logger; import org.literacyapp.dao.ContentCreationEventDao; import org.literacyapp.dao.AudioDao; import org.literacyapp.model.Contributor; import org.literacyapp.model.content.multimedia.Audio; import org.literacyapp.model.contributor.ContentCreationEvent; import org.literacyapp.model.enums.ContentLicense; import org.literacyapp.model.enums.Environment; import org.literacyapp.model.enums.content.AudioFormat; import org.literacyapp.model.enums.Team; import org.literacyapp.model.enums.content.LiteracySkill; import org.literacyapp.model.enums.content.NumeracySkill; import org.literacyapp.util.SlackApiHelper; import org.literacyapp.web.context.EnvironmentContextLoaderListener; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Controller; import org.springframework.ui.Model; import org.springframework.validation.BindingResult; import org.springframework.web.bind.ServletRequestDataBinder; import org.springframework.web.bind.annotation.InitBinder; import org.springframework.web.bind.annotation.PathVariable; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RequestMethod; import org.springframework.web.bind.annotation.RequestParam; import org.springframework.web.multipart.MultipartFile; import org.springframework.web.multipart.support.ByteArrayMultipartFileEditor; @Controller @RequestMapping("/content/multimedia/audio/edit") public class AudioEditController { private final Logger logger = Logger.getLogger(getClass()); @Autowired private AudioDao audioDao; @Autowired private ContentCreationEventDao contentCreationEventDao; @RequestMapping(value = "/{id}", method = RequestMethod.GET) public String handleRequest(Model model, @PathVariable Long id) { logger.info("handleRequest"); Audio audio = audioDao.read(id); model.addAttribute("audio", audio); model.addAttribute("contentLicenses", ContentLicense.values()); model.addAttribute("literacySkills", LiteracySkill.values()); model.addAttribute("numeracySkills", NumeracySkill.values()); model.addAttribute("contentCreationEvents", contentCreationEventDao.readAll(audio)); return "content/multimedia/audio/edit"; } @RequestMapping(value = "/{id}", method = RequestMethod.POST) public String handleSubmit(HttpSession session, Audio audio, @RequestParam("bytes") MultipartFile multipartFile, BindingResult result, Model model) { logger.info("handleSubmit"); if (StringUtils.isBlank(audio.getTranscription())) { result.rejectValue("transcription", "NotNull"); } else { Audio existingAudio = audioDao.read(audio.getTranscription(), audio.getLocale()); if ((existingAudio != null) && !existingAudio.getId().equals(audio.getId())) { result.rejectValue("transcription", "NonUnique"); } } try { byte[] bytes = multipartFile.getBytes(); if (multipartFile.isEmpty() || (bytes == null) || (bytes.length == 0)) { result.rejectValue("bytes", "NotNull"); } else { String originalFileName = multipartFile.getOriginalFilename(); logger.info("originalFileName: " + originalFileName); if (originalFileName.toLowerCase().endsWith(".mp3")) { audio.setAudioFormat(AudioFormat.MP3); } else if (originalFileName.toLowerCase().endsWith(".ogg")) { audio.setAudioFormat(AudioFormat.OGG); } else if (originalFileName.toLowerCase().endsWith(".wav")) { audio.setAudioFormat(AudioFormat.WAV); } else { result.rejectValue("bytes", "typeMismatch"); } if (audio.getAudioFormat() != null) { String contentType = multipartFile.getContentType(); logger.info("contentType: " + contentType); audio.setContentType(contentType); audio.setBytes(bytes); // TODO: convert to a default audio format? } } } catch (IOException e) { logger.error(e); } if (result.hasErrors()) { model.addAttribute("audio", audio); model.addAttribute("contentLicenses", ContentLicense.values()); model.addAttribute("literacySkills", LiteracySkill.values()); model.addAttribute("numeracySkills", NumeracySkill.values()); model.addAttribute("contentCreationEvents", contentCreationEventDao.readAll(audio)); return "content/multimedia/audio/edit"; } else { audio.setTranscription(audio.getTranscription().toLowerCase()); audio.setTimeLastUpdate(Calendar.getInstance()); audio.setRevisionNumber(Integer.MIN_VALUE); audioDao.update(audio); Contributor contributor = (Contributor) session.getAttribute("contributor"); ContentCreationEvent contentCreationEvent = new ContentCreationEvent(); contentCreationEvent.setContributor(contributor); contentCreationEvent.setContent(audio); contentCreationEvent.setCalendar(Calendar.getInstance()); contentCreationEventDao.update(contentCreationEvent); if (EnvironmentContextLoaderListener.env == Environment.PROD) { String text = URLEncoder.encode(contributor.getFirstName() + " just edited an Audio:\n" + " Language: " + audio.getLocale().getLanguage() + "\n" + " Transcription: \"" + audio.getTranscription() + "\"\n" + " Audio format: " + audio.getAudioFormat() + "\n" + "See ") + "http://literacyapp.org/content/multimedia/audio/list"; String iconUrl = contributor.getImageUrl(); SlackApiHelper.postMessage(Team.CONTENT_CREATION, text, iconUrl, "http://literacyapp.org/audio/" + audio.getId() + "." + audio.getAudioFormat().toString().toLowerCase()); } return "redirect:/content/multimedia/audio/list"; } } /** * See http://www.mkyong.com/spring-mvc/spring-mvc-failed-to-convert-property-value-in-file-upload-form/ * <p></p> * Fixes this error message: * "Cannot convert value of type [org.springframework.web.multipart.support.StandardMultipartHttpServletRequest$StandardMultipartFile] to required type [byte] for property 'bytes[0]'" */ @InitBinder protected void initBinder(HttpServletRequest request, ServletRequestDataBinder binder) throws ServletException { logger.info("initBinder"); binder.registerCustomEditor(byte[].class, new ByteArrayMultipartFileEditor()); } }