SpringMVC實(shí)現(xiàn)上傳下載文件

更新時(shí)間：2022年09月06日 11:24:26 作者：凌冰_

這篇文章主要為大家詳細(xì)介紹了SpringMVC實(shí)現(xiàn)上傳下載文件，文中示例代碼介紹的非常詳細(xì)，具有一定的參考價(jià)值，感興趣的小伙伴們可以參考一下

本文實(shí)例為大家分享了SpringMVC實(shí)現(xiàn)上傳下載文件的具體代碼，供大家參考，具體內(nèi)容如下

一、SpringMVC專門提供了CommonsMultipartResolver組件用于文件上傳：

（1）maxUploadSize 文件最大限制，單位是byte
（2）maxInMemorySize 低于這個(gè)大小的文件暫存內(nèi)存中
（3）defaultEncoding 默認(rèn)編碼utf-8

必須在spring-mvc.xml文件

<!-- (2)配置 MultipartResolver 實(shí)現(xiàn)文件上傳 ?
?? ? ? ? ? ? ? ? ?注意：id="multipartResolver"是固定寫法
?? ? ? -->
?? ? ? <bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
?? ? ? ? <!-- 字符編碼 -->
?? ? ? ?<property name="defaultEncoding" value="utf-8"/>
?? ? ? ?<!-- max size 10M -->
?? ? ? ?<property name="maxUploadSize" value="10485760000"/>
?? ? ? ?<!--內(nèi)存中最大 4K ?-->
?? ? ? ?<property name="maxInMemorySize" value="4096"/>
?? ? ? </bean>

二、SpringMVC文件上傳引入jar包

必須在配置Pom.xml文件

<!-- fileupload start -->
?? ??? ?<dependency>
?? ??? ??? ?<groupId>commons-fileupload</groupId>
?? ??? ??? ?<artifactId>commons-fileupload</artifactId>
?? ??? ??? ?<version>1.3.1</version>
?? ??? ?</dependency>
?
?? ??? ?<dependency>
?? ??? ??? ?<groupId>commons-io</groupId>
?? ??? ??? ?<artifactId>commons-io</artifactId>
?? ??? ??? ?<version>2.4</version>
?? ??? ?</dependency>
?
?? ??? ?<!-- end -->

三、實(shí)現(xiàn)【單個(gè)文件】上傳

（1）JSP頁面必須放在WEB-INF下 upload1.jsp 必須添加enctype="multipart/form-data"

<body>
?? ?<div style="margin: 0 auto; margin-top: 100px; background:snow">
?? ??? ?<form method="post" action="upload1.html" name="form1"
?? ??? ??? ?enctype="multipart/form-data">
?? ??? ??? ?<p>
?? ??? ??? ??? ? ?照片：<input type="file" name="imagefile">
?? ??? ??? ??? ?<input type="submit" value="上傳" name="button1"> <br>
?? ??? ??? ?</p>
?? ??? ?</form>
?? ?</div>

(2) 寫控制類 UploadController.java

@Controller
public class UploadController {
?
?? ?@RequestMapping("upload1")
?? ?public String getUpload(@RequestParam("imagefile") MultipartFile imagefile,
?? ??? ??? ?HttpServletRequest request) {
?? ??? ?// 獲取上傳的服務(wù)器路徑
?? ??? ?String pathString = request.getSession().getServletContext().getRealPath("/upload/");
?? ??? ?// 獲取文件
?? ??? ?String fileName = imagefile.getOriginalFilename();
?? ??? ?
?? ??? ?System.out.println(fileName);
?
?? ??? ?// 判斷上傳的路徑是否存在
?? ??? ?File file = new File(pathString);
?? ??? ?if (!file.exists()) {
?? ??? ??? ?file.mkdirs();
?? ??? ?}
?
?? ??? ?System.out.println("上傳路徑=" + pathString +"/"+ fileName);
?? ??? ?// 文件不存在
?? ??? ?File targetFile = new File(pathString +"/"+ fileName);
?? ??? ?if (!targetFile.exists()) {
?? ??? ??? ?try {
?? ??? ??? ??? ?targetFile.createNewFile();
?? ??? ??? ?} catch (IOException e) {
?? ??? ??? ??? ?// TODO Auto-generated catch block
?? ??? ??? ??? ?e.printStackTrace();
?? ??? ??? ?}
?? ??? ?}
?
?? ??? ?try {
?? ??? ??? ?// 上傳
?? ??? ??? ?imagefile.transferTo(targetFile);
?? ??? ?} catch (IllegalStateException e) {
?? ??? ??? ?// TODO Auto-generated catch block
?? ??? ??? ?e.printStackTrace();
?? ??? ?} catch (IOException e) {
?? ??? ??? ?// TODO Auto-generated catch block
?? ??? ??? ?e.printStackTrace();
?? ??? ?}
?
?? ??? ?//注意：/springmvc5/WEB-INF/jsp/http:/localhost:8888/springmvc5/upload/1.gif.jsp
?? ??? ?//返回文件，必須是重定向文件
?? ??? ?return "redirect:http://localhost:8888/springmvc5/upload/" + fileName;
?
?? ?} }

(3)效果

選擇圖片路徑:

單擊上傳：

四、實(shí)現(xiàn)【多個(gè)文件】上傳

（1）JSP頁面(必須放在WEB-INF下) upload2.jsp 必須添加enctype="multipart/form-data"

<body>
?? ?<div style="margin: 0 auto; margin-top: 100px; background:snow">
?? ??? ?<form method="post" action="upload2.html" name="form1"
?? ??? ??? ?enctype="multipart/form-data">
?? ??? ??? ?<p>
?? ??? ??? ??? ? ?照片1：<input type="file" name="imagefile1"><p/>
?? ??? ??? ??? ? ?照片2：<input type="file" name="imagefile2"><p/>
?? ??? ??? ??? ?<input type="submit" value="上傳" name="button1"> <br>
?? ??? ??? ?</p>
?? ??? ?</form>
?? ?</div>
</body>

(2) 寫控制類 UploadController.java

@RequestMapping("upload2")
?? ?public String getUpload2(HttpServletRequest request) {
?
?? ??? ?// 多文件上傳
?? ??? ?MultipartHttpServletRequest multipartRequest = (MultipartHttpServletRequest) request;
?? ??? ?// 獲得多個(gè)文件
?? ??? ?Map<String, MultipartFile> map = multipartRequest.getFileMap();
?
?? ??? ?// 獲取上傳的服務(wù)器路徑
?? ??? ?String pathString = request.getSession().getServletContext().getRealPath("/upload/");
?? ??? ?// 判斷上傳的路徑是否存在
?? ??? ?File file1 = new File(pathString);
?? ??? ?if (!file1.exists()) {
?? ??? ??? ?file1.mkdirs();
?? ??? ?}
?
?? ??? ?// 獲取文件
?? ??? ?List<String> list = new ArrayList<String>();
?
?? ??? ?// 遍歷數(shù)據(jù)
?? ??? ?for (MultipartFile file : map.values()) {
?? ??? ??? ?String fileName = file.getOriginalFilename();
?? ??? ??? ?System.out.println("上傳路徑=" + pathString +"/"+ fileName);
?? ??? ??? ?// 文件不存在
?? ??? ??? ?File targetFile = new File(pathString ?+"/"+ fileName);
?? ??? ??? ?if (!targetFile.exists()) {
?? ??? ??? ??? ?try {
?? ??? ??? ??? ??? ?targetFile.createNewFile();
?? ??? ??? ??? ?} catch (IOException e) {
?? ??? ??? ??? ??? ?// TODO Auto-generated catch block
?? ??? ??? ??? ??? ?e.printStackTrace();
?? ??? ??? ??? ?}
?? ??? ??? ?}
?
?? ??? ??? ?try {
?? ??? ??? ??? ?// 上傳
?? ??? ??? ??? ?file.transferTo(targetFile);
?
?? ??? ??? ??? ?// 保存路徑
?? ??? ??? ??? ?list.add("http://localhost:8888/springmvc5/upload/" + fileName);
?? ??? ??? ?} catch (IllegalStateException e) {
?? ??? ??? ??? ?// TODO Auto-generated catch block
?? ??? ??? ??? ?e.printStackTrace();
?? ??? ??? ?} catch (IOException e) {
?? ??? ??? ??? ?// TODO Auto-generated catch block
?? ??? ??? ??? ?e.printStackTrace();
?? ??? ??? ?}
?
?? ??? ?}
?? ??? ?// 保存每個(gè)上傳的路徑
?? ??? ?request.setAttribute("files", list);
?? ??? ?
?? ??? ?return "showUpload"; ? //跳轉(zhuǎn)到showUpload.jsp頁面哦！
?
?? ?}

注意：return "showUpload";是具體顯示的頁面;必須配置視圖解析器在spring-mvc.xml文件中

<!--(1) spring 視圖解析器 -->
<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver"
p:prefix="/WEB-INF/jsp/" ?p:suffix=".jsp"></bean>

(3)JSP頁面: showUpload.jsp

<div style="margin: 0 auto; margin-top: 100px; background:snow">
?? ? ?<%
?? ? ? ?List<String> list =(List<String>) request.getAttribute("files");
?? ? ? ?
?? ? ? ?for(String str:list){
?? ? ?
?? ? ? %>
?? ? ? ? ?<a href="<%=str%>" rel="external nofollow" ><img src="<%=str%>" alt=""/></a>
?? ? ??
?? ? ? <%} %>
</div>

(4)效果

單擊上傳：

查看上傳到服務(wù)器的圖片

五、下載圖片

(1)JSP頁面 login.jsp

<a href="download.html?fileName=08.gif" >下載圖片</a><p/>

(2)控制類DownController

@Controller
public class DownController {
?
?? ?@RequestMapping("/download")
?? ?public String download(@RequestParam String fileName,
?? ??? ??? ?HttpServletRequest request, HttpServletResponse response) {
?
?? ??? ?// 設(shè)置響應(yīng)編碼
?? ??? ?response.setContentType("text/html;charset=utf-8");
?
?? ??? ?// 設(shè)置請(qǐng)求編碼
?? ??? ?try {
?? ??? ??? ?request.setCharacterEncoding("utf-8");
?? ??? ?} catch (UnsupportedEncodingException e) {
?? ??? ??? ?// TODO Auto-generated catch block
?? ??? ??? ?e.printStackTrace();
?? ??? ?}
?
?? ??? ?// 字節(jié)流
?? ??? ?BufferedInputStream bis=null;
?? ??? ?BufferedOutputStream bos=null;
?
?? ??? ?// 獲取服務(wù)器的路徑
?? ??? ?String path = request.getSession().getServletContext().getRealPath("/upload/");
?
?? ??? ?// 下載的路徑
?? ??? ?String downPath = path +"/"+ fileName;
?
?? ??? ?try {
?? ??? ??? ?// 文件大小
?? ??? ??? ?long fileSize = new File(downPath).length();
?? ??? ??? ?
?? ??? ??? ?//設(shè)置內(nèi)容類型
?? ??? ??? ?response.setContentType("application/x-msdownload");
?? ??? ??? ?//設(shè)置頭信息
?? ??? ??? ?response.setHeader("Content-disposition", "attachment; filename="+new String(fileName.getBytes("utf-8"),"ISO8859-1"));
?? ??? ??? ?response.setHeader("Content-Length",String.valueOf(fileSize));
?? ??? ??? ?//字節(jié)流
?? ??? ??? ?bis = new BufferedInputStream(new FileInputStream(downPath));
?? ??? ??? ?bos= new BufferedOutputStream(response.getOutputStream());
?? ??? ??? ?//字節(jié)數(shù)組
?? ??? ??? ?byte[] by = new byte[2048];
?? ??? ??? ?
?? ??? ??? ?//
?? ??? ??? ?int length=0;
?? ??? ??? ?
?? ??? ??? ?//讀取
?? ??? ??? ?while((length=bis.read(by,0,by.length))!=-1){
?? ??? ??? ??? ?//寫入
?? ??? ??? ??? ?bos.write(by, 0, length);
?? ??? ??? ??? ?
?? ??? ??? ?}
?? ??? ??? ?
?? ??? ?} catch (Exception e) {
?? ??? ??? ?// TODO: handle exception
?? ??? ??? ?e.printStackTrace();
?? ??? ?}finally{
?? ??? ??? ?//關(guān)閉連接
?? ??? ??? ? if(bis!=null){
?? ??? ??? ??? ? try {
?? ??? ??? ??? ??? ?bis.close();
?? ??? ??? ??? ?} catch (IOException e) {
?? ??? ??? ??? ??? ?// TODO Auto-generated catch block
?? ??? ??? ??? ??? ?e.printStackTrace();
?? ??? ??? ??? ?}
?? ??? ??? ? }
?? ??? ??? ? if(bos!=null){
?? ??? ??? ??? ? try {
?? ??? ??? ??? ??? ? bos.close();
?? ??? ??? ??? ? } catch (IOException e) {
?? ??? ??? ??? ??? ? // TODO Auto-generated catch block
?? ??? ??? ??? ??? ? e.printStackTrace();
?? ??? ??? ??? ? }
?? ??? ??? ? }
?? ??? ?}
?
?? ??? ?return null;
?
?? ?}
}

(3)效果