MyBatis與SpringMVC相結(jié)合實(shí)現(xiàn)文件上傳、下載功能

更新時(shí)間：2016年06月23日 14:47:23 作者：Alfa

這篇文章主要介紹了MyBatis與SpringMVC相結(jié)合實(shí)現(xiàn)文件上傳、下載功能的相關(guān)資料,非常不錯(cuò)，具有參考借鑒價(jià)值，需要的朋友可以參考下

環(huán)境：maven+SpringMVC + Spring + MyBatis + MySql

本文主要說明如何使用input上傳文件到服務(wù)器指定目錄，或保存到數(shù)據(jù)庫中；如何從數(shù)據(jù)庫下載文件，和顯示圖像文件并實(shí)現(xiàn)縮放。

將文件存儲(chǔ)在數(shù)據(jù)庫中，一般是存文件的byte數(shù)組，對(duì)應(yīng)的數(shù)據(jù)庫數(shù)據(jù)類型為blob。

首先要?jiǎng)?chuàng)建數(shù)據(jù)庫，此處使用MySql數(shù)據(jù)庫。

注意：文中給出的代碼多為節(jié)選重要片段，并不齊全。

1. 前期準(zhǔn)備

使用maven創(chuàng)建一個(gè)springMVC+spring+mybatis+mysql的項(xiàng)目。

關(guān)于如何整合Spring+mybatis+mysql，請(qǐng)見MyBatis簡(jiǎn)介與配置MyBatis+Spring+MySql：

MyBatis學(xué)習(xí) 之一、MyBatis簡(jiǎn)介與配置MyBaits+Spring+MySql

關(guān)于SpringMVC環(huán)境的搭建請(qǐng)見：使用Eclipse構(gòu)建Maven的SpringMVC項(xiàng)目：

使用Eclipse構(gòu)建Maven的SpringMVC項(xiàng)目

在前臺(tái)html中，form的enctype為multipart/form-data。注意input、select的name要和StudentForm中成員一一對(duì)應(yīng)。

上傳的url為addAction.do，此action方法的參數(shù)中使用StudentForm來映射提交的數(shù)據(jù)。此時(shí)就可以獲取到提交的文件的數(shù)據(jù)。然后我們就對(duì)文件進(jìn)行操作。

創(chuàng)建PHOTO_TBL表：PHOTO_DATA字段用于存放文件，類型為MyBatis的longblob；然后寫Mapper的Java接口PhotoMapper：包括增刪改查；mapper的xml文件：對(duì)應(yīng)JAVA接口的sql語句。

并且需要Spring配置文件添加一個(gè)bean的聲明。

下面給出html、action、StudentForm的代碼片段；創(chuàng)建PHOTO_TBL表的sql、PhotoMapper.java接口代碼、PhotoMapper.xml文件代碼。

1.1 html的form表單寫法

1.<form action="<c:url value='addAction.do' />" method="post" enctype="multipart/form-data"> 
2. <table> 
3. <tr> 
4. <td width="100" align="right">照片：</td> 
5. <td><input type="file" name="studentPhoto"/></td> 
6. </tr> 
7. </table> 
8. <input type="submit"> 
9.</form>

1.2 action方法

1./** 
2. * 新增 - 提交 
3. */ 
4.@RequestMapping(value = "addAction.do") 
5.public String add_action(ModelMap model, StudentForm form) { 
6. 
7.}

1.3 StudentForm類

1.package liming.student.manager.web.model; 
2. 
3.import org.springframework.web.multipart.MultipartFile; 
4. 
5.public class StudentForm extends GeneralForm { 
6. 
7. private String studentName; 
8. private int studentSex; 
9. private String studentBirthday; 
10. private MultipartFile studentPhoto; 
11. 
12.}

1.4 創(chuàng)建PHOTO_TBL

1.CREATE TABLE PHOTO_TBL 
2.( 
3. PHOTO_ID VARCHAR(100) PRIMARY KEY, 
4. PHOTO_DATA LONGBLOB, 
5. FILE_NAME VARCHAR(10) 
6.);

1.5 PhotoMapper接口

1.@Repository 
2.@Transactional 
3.public interface PhotoMapper { 
4. 
5. public void createPhoto(PhotoEntity entity); 
6. 
7. public int deletePhotoByPhotoId(String photoId); 
8. 
9. public int updatePhotoDate(@Param("photoId") String photoId, @Param("photoDate") byte[] photoDate); 
10. 
11. public PhotoEntity getPhotoEntityByPhotoId(String photoId); 
12. 
13.}

1.6 PhotoMapper.xml文件

包括增、刪、改、查。其中新增中的photoId使用的是mysql自定義函數(shù)自動(dòng)生成主鍵。在操作blob時(shí)需要制定typeHandler為"org.apache.ibatis.type.BlobTypeHandler。insert、update時(shí)參數(shù)后面需要指定，resultMap中需要指定。

1.<?xml version="1.0" encoding="UTF-8" ?> 
2.<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd"> 
3.<mapper namespace="liming.student.manager.data.PhotoMapper"> 
4. <resultMap type="liming.student.manager.data.model.PhotoEntity" id="photoMapper_resultMap_photoEntity"> 
5. <id property="photoId" column="PHOTO_ID" javaType="String" jdbcType="VARCHAR" /> 
6. <result property="photoData" column="PHOTO_DATA" javaType="byte[]" jdbcType="BLOB" typeHandler="org.apache.ibatis.type.BlobTypeHandler" /> 
7. <result property="fileName" column="FILE_NAME" javaType="String" jdbcType="VARCHAR" /> 
8. </resultMap> 
9. 
10. <insert id="createPhoto" parameterType="liming.student.manager.data.model.PhotoEntity"> 
11. <selectKey keyProperty="photoId" resultType="String" order="BEFORE"> 
12. select nextval('photo') 
13. </selectKey> 
14. INSERT INTO PHOTO_TBL(PHOTO_ID, 
15. PHOTO_DATA, 
16. FILE_NAME) 
17. VALUES(#{photoId, jdbcType=VARCHAR}, 
18. #{photoData, javaType=byte[], jdbcType=BLOB, typeHandler=org.apache.ibatis.type.BlobTypeHandler}, 
19. #{fileName, jdbcType=VARCHAR}) 
20. </insert> 
21. 
22. <delete id="deletePhotoByPhotoId"> 
23. DELETE FROM PHOTO_TBL 
24. WHERE PHOTO_ID = #{photoId, jdbcType=VARCHAR} 
25. </delete> 
26. 
27. <update id="updatephotoData" > 
28. UPDATE PHOTO_TBL 
29. SET PHOTO_DATA = #{photoData, javaType=byte[], jdbcType=BLOB, typeHandler=org.apache.ibatis.type.BlobTypeHandler}, 
30. FILE_NAME = #{fileName, jdbcType=VARCHAR} 
31. WHERE PHOTO_ID = #{photoId, jdbcType=VARCHAR} 
32. </update> 
33. 
34. <select id="getPhotoEntityByPhotoId" resultMap="photoMapper_resultMap_photoEntity"> 
35. SELECT PHOTO_ID, 
36. PHOTO_DATA, 
37. FILE_NAME 
38. FROM PHOTO_TBL 
39. WHERE PHOTO_ID = #{photoId, jdbcType=VARCHAR} 
40. </select> 
41.</mapper>

1.7 spring配置文件

需要Spring配置文件添加一個(gè)org.springframework.web.multipart.commons.CommonsMultipartResolver的bean的聲明。

1.<bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver"> 
2. <property name="maxUploadSize" value="1073741824" /> 
3.</bean>

2. 將文件到服務(wù)器上

1.private static final String uploadFilePath = "d:\\temp_upload_file\\"; 
2. 
3./** 
4. * 新增 - 提交 – 只保存文件到服務(wù)器上 
5. */ 
6.@RequestMapping(value = "addAction.do") 
7.public String add_action(ModelMap model, StudentForm form) { 
8.try { 
9. MultipartFile uploadFile = form.getStudentPhoto(); 
10. String filename = uploadFile.getOriginalFilename(); 
11. InputStream is = uploadFile.getInputStream(); 
12. // 如果服務(wù)器已經(jīng)存在和上傳文件同名的文件，則輸出提示信息 
13. File tempFile = new File(uploadFilePath + filename); 
14. if (tempFile.exists()) { 
15. boolean delResult = tempFile.delete(); 
16. System.out.println("刪除已存在的文件：" + delResult); 
17. } 
18. // 開始保存文件到服務(wù)器 
19. if (!filename.equals("")) { 
20. FileOutputStream fos = new FileOutputStream(uploadFilePath + filename); 
21. byte[] buffer = new byte[8192]; // 每次讀8K字節(jié) 
22. int count = 0; 
23. // 開始讀取上傳文件的字節(jié)，并將其輸出到服務(wù)端的上傳文件輸出流中 
24. while ((count = is.read(buffer)) > 0) { 
25. fos.write(buffer, 0, count); // 向服務(wù)端文件寫入字節(jié)流 
26. } 
27. fos.close(); // 關(guān)閉FileOutputStream對(duì)象 
28. is.close(); // InputStream對(duì)象 
29. } 
30. } catch (FileNotFoundException e) { 
31. e.printStackTrace(); 
32. } catch (IOException e) { 
33. e.printStackTrace(); 
34. } 
35.}

3. 將文件上傳到數(shù)據(jù)庫中

1./** 
2. * 新增 - 提交 – 保存文件到數(shù)據(jù)庫 
3. */ 
4.@RequestMapping(value = "addAction.do") 
5.public String add_action(ModelMap model, StudentForm form) { 
6. InputStream is = form.getStudentPhoto().getInputStream(); 
7. byte[] studentPhotoData = new byte[(int) form.getStudentPhoto().getSize()]; 
8. is.read(studentPhotoData); 
9. String fileName = form.getStudentPhoto().getOriginalFilename(); 
10. PhotoEntity photoEntity = new PhotoEntity(); 
11. photoEntity.setPhotoData(studentPhotoData); 
12. photoEntity.setFileName(fileName); 
13. this.photoMapper.createPhoto(photoEntity); 
14.}

4.下載文件

下載文件需要將byte數(shù)組還原成文件。

首先使用mybatis將數(shù)據(jù)庫中的byte數(shù)組查出來，指定文件名(包括格式)。然后使用OutputStream將文件輸入

1.@RequestMapping(value = "downPhotoById") 
2.public void downPhotoByStudentId(String id, final HttpServletResponse response){ 
3. PhotoEntity entity = this.photoMapper.getPhotoEntityByPhotoId(id); 
4. byte[] data = entity.getPhotoData(); 
5. String fileName = entity.getFileName()== null ? "照片.png" : entity.getFileName(); 
6. fileName = URLEncoder.encode(fileName, "UTF-8"); 
7. response.reset(); 
8. response.setHeader("Content-Disposition", "attachment; filename=\"" + fileName + "\""); 
9. response.addHeader("Content-Length", "" + data.length); 
10. response.setContentType("application/octet-stream;charset=UTF-8"); 
11. OutputStream outputStream = new BufferedOutputStream(response.getOutputStream()); 
12. outputStream.write(data); 
13. outputStream.flush(); 
14. outputStream.close(); 
15.}

<a href="<%=request.getContextPath() %>/downPhotoById.do?id=8000001">下載照片</a>

5. 顯示byte圖片文件

1.@RequestMapping(value = "getPhotoById") 
2.public void getPhotoById (String id, final HttpServletResponse response){ 
3. PhotoEntity entity = this.photoMapper.getPhotoEntityByPhotoId(id); 
4. byte[] data = entity.getPhotoData(); 
5. response.setContentType("image/jpeg"); 
6. response.setCharacterEncoding("UTF-8"); 
7. OutputStream outputSream = response.getOutputStream(); 
8. InputStream in = new ByteArrayInputStream(data); 
9. int len = 0; 
10. byte[] buf = new byte[1024]; 
11. while ((len = in.read(buf, 0, 1024)) != -1) { 
12. outputSream.write(buf, 0, len); 
13. } 
14. outputSream.close(); 
15.}

<img src="<%=request.getContextPath() %>/getPhotoById.do?id=8000001"/>

6. 按長(zhǎng)寬等比例縮放圖片

1.@RequestMapping(value = "getPhotoId") 
2.public void getPhotoById (String id, int width, int height, final HttpServletResponse response){ 
3. PhotoEntity entity = this.photoMapper.getPhotoEntityByPhotoId(id); 
4. byte[] data = entity.getPhotoData(); 
5. if (width != 0 && height != 0) { 
6. data = scaleImage(data, width, height); 
7. } 
8. response.setContentType("image/jpeg"); 
9. response.setCharacterEncoding("UTF-8"); 
10. OutputStream outputSream = response.getOutputStream(); 
11. InputStream in = new ByteArrayInputStream(data); 
12. int len = 0; 
13. byte[] buf = new byte[1024]; 
14. while ((len = in.read(buf, 0, 1024)) != -1) { 
15. outputSream.write(buf, 0, len); 
16. } 
17. outputSream.close(); 
18.} 
19. 
20.public static byte[] scaleImage(byte[] data, int width, int height) throws IOException { 
21. BufferedImage buffered_oldImage = ImageIO.read(new ByteArrayInputStream(data)); 
22. int imageOldWidth = buffered_oldImage.getWidth(); 
23. int imageOldHeight = buffered_oldImage.getHeight(); 
24. double scale_x = (double) width / imageOldWidth; 
25. double scale_y = (double) height / imageOldHeight; 
26. double scale_xy = Math.min(scale_x, scale_y); 
27. int imageNewWidth = (int) (imageOldWidth * scale_xy); 
28. int imageNewHeight = (int) (imageOldHeight * scale_xy); 
29. BufferedImage buffered_newImage = new BufferedImage(imageNewWidth, imageNewHeight, BufferedImage.TYPE_INT_RGB); 
30. buffered_newImage.getGraphics().drawImage(buffered_oldImage.getScaledInstance(imageNewWidth, imageNewHeight, BufferedImage.SCALE_SMOOTH), 0, 0, null); 
31. buffered_newImage.getGraphics().dispose(); 
32. ByteArrayOutputStream outPutStream = new ByteArrayOutputStream(); 
33. ImageIO.write(buffered_newImage, "jpeg", outPutStream); 
34. return outPutStream.toByteArray(); 
35.}

<img src="<%=request.getContextPath() %>/getPhotoById.do?id=8000001&width=300&height=300"/>

以上所述是小編給大家介紹的MyBatis與SpringMVC相結(jié)合實(shí)現(xiàn)文件上傳、下載功能，希望對(duì)大家有所幫助，如果大家有任何疑問請(qǐng)給我留言，小編會(huì)及時(shí)回復(fù)大家的。在此也非常感謝大家對(duì)腳本之家網(wǎng)站的支持！

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